Influenza vaccine

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Influenza vaccine , also known as flu shot or jabs flu , is a vaccine that protects against infection by the Influenza virus. New versions of the vaccine are developed twice a year, as the influenza virus quickly changes. Although its effectiveness varies from year to year, most provide low protection against influenza. CDC estimates that vaccination against influenza reduces illness, medical visits, hospitalization, and death. When immunized workers are exposed to the flu, they return on average to work half a day faster. The effectiveness of vaccines in those under two years and above 65 years remains unknown due to the low quality of the study. Children's vaccinations can protect the people around them.

The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) recommend annual vaccinations for almost anyone over six months of age, especially those at high risk. The European Center for Disease Prevention and Control also recommends an annual vaccination of high-risk groups. These groups include pregnant women, the elderly, children between six months and five years, those with other health problems, and those who work in health care.

Vaccines are generally safe. Fever occurs in five to ten percent of the children vaccinated. Temporary muscle pains or fatigue may also occur. In certain years, the vaccine has been associated with an increase in Guillain-BarrÃÆ'Â Â © Â © syncope among elderly people at a rate of about one case per million doses. Should not be given to those who are allergic to eggs or previous versions of vaccines. The vaccine comes in both inactive and weak forms of virus. Inactive versions should be used for those who are pregnant. They come in a form that is injected into the muscle, sprayed onto the nose, or injected into the middle layer of the skin.

Vaccination against influenza began in the 1930s with large-scale availability in the United States beginning in 1945. This is a List of Essential Medicines of the World Health Organization, the most effective and safe medicines needed in the health system. Wholesale prices in developing countries are around $ 5.25 USD per dose in 2014. In the United States, it costs less than $ 25 USD in 2015.

Video Influenza vaccine

Medical use

The US Centers for Disease Control and Prevention (CDC) recommends flu vaccine as the best way to protect people from the flu and prevent its spread. Flu vaccines can also reduce the severity of the flu if a person has a flu strain that does not contain the vaccine. It takes about two weeks after vaccination for protective antibodies is formed.

A 2012 meta-analysis found that flu vaccination was effective 67 Ã, percent of the time; the most beneficiary populations were HIV-positive adults aged 18 to 55 years (76 percent), healthy adults age 18 to 46 (about 70 percent), and healthy children sons ages six to 24 months (66 Ã, percent).

Effectiveness

The vaccine is assessed by its efficacy ; the extent to which it reduces the risk of disease under controlled conditions, and its effectiveness , the risk reduction observed after the vaccine begins to be used. In the case of influenza, the effectiveness is expected to be lower than efficacy as measured by the level of diseases such as influenza, which is not always caused by influenza. Influenza vaccines generally show high efficacy, as measured by antibody production in animal models or vaccinated individuals. However, the study of the effectiveness of flu vaccines in the real world is difficult; vaccines may not be perfectly matched, the viral prevalence varies greatly between years, and influenza is often confused with diseases like other influenza. However, in most of the year (16 of 19 years before 2007), flu vaccine strains have been suitable for circulating strains, and even unsuitable vaccines can often provide cross protection.

Live and inactive influenza vaccine trials have been summarized in several meta-analyzes 2012. Studies of live vaccines have very limited data, but these preparations may be more effective than inactivated vaccines. Meta-analysis checks the efficacy and effectiveness of inactivated vaccines against seasonal influenza in adults, children, and the elderly.

Children

The CDC recommends that everyone except infants under six months of age should receive seasonal influenza vaccines. Vaccination campaigns typically focus on people at high risk of serious complications if they have flu, such as pregnant women, children over six months old, and people with chronic illness or weak immune systems, and those who they are exposed to, such as health care workers.

Because mortality rates are also high among infants infected with influenza, household contact and infant caregivers should be vaccinated to reduce the risk of transmitting infections in infants.

In children, the vaccine again shows high efficacy, but low effectiveness in preventing "flu-like illness". In children under the age of two, the data are very limited, but vaccinations do not seem to provide measurable benefits. During the 2017-18 flu season, the CDC director indicated that 85 percent of children who die "are unlikely to be vaccinated."

Adult

In unvaccinated adults, 16% received symptoms similar to flu, while about 10% of adults were vaccinated. Vaccination reduced confirmed cases of influenza from about 2.4% to 1.1%. No effect on hospitalization was found.

In working adults, a review by Cochrane Collaboration found that vaccination resulted in a slight decrease in both influenza symptoms and lost working days, without affecting influenza-related transmission or complications. In healthy working adults, influenza vaccine can provide moderate protection against virologically confirmed influenza, although the protection is greatly reduced or absent in some seasons.

In health care workers, a 2006 review found net benefits. Of the eighteen studies in this review, only two also assessed the patient's mortality relationship relative to staff influenza vaccine uptake; both found that higher rates of health care workers vaccinated were correlated with reduced patient mortality. The 2014 review finds benefits for patients when health care workers are immunized, as supported by moderate evidence that is based in part on observed reductions in all causes of death in patients whose health care workers are immunized compared to comparison patients where healthcare workers are not offered the vaccine.

Elderly

Evidence for effects in adults over 65 years is unclear. A systematic review examined both randomized controlled studies and case studies found a lack of high-quality evidence. A case study review of controls found an effect on laboratory-confirmed influenza, pneumonia, and death among elderly people living in the community.

The group most vulnerable to the non-pandemic flu, the elderly, the least benefit of the vaccine. There are several reasons behind the sharp decline in vaccine efficacy, the most common being the decline in immunological function and the fragility associated with old age. In a non-pandemic year, a person in the United States aged 50-64 is almost ten times more likely to die from influenza-related deaths than younger people, and people over 65 are more than ten times more likely to die. influenza-related deaths than the 50-64 age group.

There is a high dose flu vaccine that is specifically formulated to provide a stronger immune response. Evidence suggests that vaccinating older people with high-dose vaccines leads to a stronger immune response to influenza than regular dose vaccines.

The adjuvant-containing flu vaccine has been approved by the US Food and Drug Administration (FDA) in November 2015, for use by adults aged 65 and older. The vaccine is marketed as Fluad in the US and is first available in flu season 2016-2017. The vaccine contains an adjuvant MF59C.1 which is an oil-in-water emulsion of squalene oil. This is the first seasonally adapted flu vaccine marketed in the United States. It is unclear whether there is a significant benefit for parents to use flu vaccine containing adjuvant MF59C.1. Per the Advisory Committee on Immunization Practice Guidelines, Fluad can be used as an alternative to other approved influenza vaccines for people aged 65 and older.

Vaccination of health care workers working with parents is recommended in many countries, with the aim of reducing the outbreak of influenza in this vulnerable population. Although there is no conclusive evidence from randomized clinical trials that vaccinations of health care workers help protect elderly people from influenza, there is evidence of temporary benefits.

Pregnancy

In addition to protecting mothers and children from the effects of influenza infection, immunization of pregnant women tends to increase their chances of having successful full pregnancies.

Inactivated trivalent influenza vaccine is protective in HIV-infected pregnant women.

Maps Influenza vaccine

Security

While side effects of flu vaccines may occur, they are usually small. Flu vaccines can cause serious side effects, including allergic reactions, but this is rare. In addition, the usual side effects and risks of inoculation are mild and transient when compared with the risks and adverse health effects of well documented annual influenza epidemics of disease, hospitalization, and death.

Flu vaccines can cause side effects like colds and sore throats, which can last up to several days. An egg allergy can also be a concern, since flu vaccines are usually made using eggs; However, research on egg allergies and influenza vaccinations has led some advisory groups to recommend vaccines for those with mild allergies and monitor vaccinations for those with more severe symptoms. A large study of nearly 800 children in the UK with egg allergies, including more than 250 with previous anaphylactic reactions, had a systemic allergic reaction of zero when administered an attenuated live flu vaccine. On January 17, 2013, the US FDA approved Flublok, the fast-moving influenza vaccine that was the first to grow in insect cells, not eggs. Since the egg is not used in its production, it will not have any problems with the egg allergy.

Although Guillain-BarrÃÆ' © s syndrome has been feared as a complication of vaccination, the CDC states that most studies on modern influenza vaccines do not see anything to do with Guillain-Barrà ©  ©. Influenza virus infection itself increases the risk of death (up to 1 in 10,000) and increases the risk of developing Guillain-Barrà © Ã… © syndrome to a much higher level than the highest level of suspected vaccine involvement (about 10 times higher in 2009 estimates).

Although one review provides an incident of about one case of Guillain-BarrÃÆ'  © per million vaccinations, a major study in China, reported in The New England Journal of Medicine that includes nearly 100 million sponsors the dose of vaccine against the 2009 H1N1 flu "swine flu" found only eleven cases of Guillain-Barrà © Ã… © syndrome (0.1 per million doses) total incidence in vaccinated people is actually lower than the normal level of disease in China, and no effect other important side; "The risk-benefit ratio, which is what vaccines and everything in medicine, strongly supports vaccinations." Several studies have identified an increased incidence of narcolepsy among pandemic recipients of the H1N1 influenza ASO3-adjuvanted vaccine; attempts to identify mechanisms for this suggest that narcolepsy is autoimmune, and that ASO3-adjuvanted H1N1 vaccine can mimic hypocretin, acting as a trigger.

Some injectable flu vaccines intended for adults in the United States contain thiomersal (also known as thimerosal), a mercury-based preservative. Despite some media controversies, the World Health Advisory Committee on Global Vaccine Safety has concluded that there is no evidence of toxicity from thiomersal in the vaccine and there is no reason on the basis of security to turn into a more expensive single dose administration.

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Injection versus nasal spray

The flu vaccine is available as either:

• trivalent or quadrivalent injection (TIV or QIV), which contains inactive virus forms
• a live attenuated influenza vaccine spray (LAIV, Q/LAIV), which contains an attenuated or weakened form of the virus.

TIV induces protection after injection (usually intramuscularly, although subcutaneous and intradermal routes may also be protective) based on immune responses to antigens present in inactive viruses, while cold-adapted LAIV works by establishing infections of the nasal passages.

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Recommendations

Various public health organizations, including the World Health Organization, have recommended that annual influenza vaccinations are routinely offered, especially for people at risk of influenza complications and people living with or treating high-risk individuals, including:

• elderly (UK recommendation is those 65 years old)
• people with chronic lung disease (asthma, COPD, etc.)
• people with chronic heart disease (congenital heart disease, chronic heart failure, ischemic heart disease)
• people with chronic liver disease (including cirrhosis)
• people with chronic kidney disease (such as nephrotic syndrome)
• people who are immunosuppressed (people with HIV or who receive drugs to suppress the immune system such as chemotherapy and long-term steroids) and their household contacts
• people who live together in large numbers in an environment where influenza can spread rapidly, such as prisons, nursing homes, schools, and dormitories.
• healthcare workers (both to prevent disease and prevent spread to patients)
• pregnant woman. However, the 2009 review concludes that there is insufficient evidence to recommend routine use of trivalent influenza vaccine during the first trimester of pregnancy. Influenza vaccination during the flu season is part of a recommendation for influenza vaccination in pregnant women in the United States.

Both types of flu vaccine are contraindicated for those who have severe allergies to egg proteins and people with a history of Guillain-Barrà ©  © syndrome.

World Health Organization

In 2016, the World Health Organization recommends seasonal influenza vaccinations to:

Highest priority:

1. Pregnant women

Priority (in no particular order):

1. Children aged 6-59 months
2. Elderly
3. Individuals with certain chronic medical conditions
4. Health care workers

Canada

In 2008, the National Advisory Committee on Immunization, a group advising the Canadian Public Health Agency, recommended that all persons two to 64 years old are encouraged to receive annual influenza vaccinations, and that children between the ages of six and 24 months, and their household contacts, should be regarded as a high priority for flu vaccines. NACI also recommends flu vaccines to:

• High-risk people experience influenza-related complications or hospitalization, including healthy and unhealthy pregnant women, children aged six to 59 months, parents, indigenous peoples, and people suffering from one of the detailed lists chronic health provisions
• Persons capable of transmitting influenza to those at high risk, including household contacts and health care workers
• The person providing the essential community services
• Certain poultry workers

Europe

The European Center for Disease Prevention and Control recommends to vaccinate the elderly as a priority, with secondary priority people with chronic medical conditions and healthcare workers.

Influenza vaccination strategies generally protect vulnerable people, rather than limiting the circulation of influenza or completely eliminating human influenza illness. This is in contrast to high flock immunity strategies for other infectious diseases such as polio and measles. This is also partly due to the financial and logistical burdens associated with annual injection requirements.

United States

In the United States routine influenza vaccination is recommended for all people aged> = 6 Ã, months.

According to the CDC, the attenuated live virus (which comes in the form of a nasal spray in the US) should be avoided by:

• Children younger than two years
• Adult 50 years
• People with a history of severe allergic reactions to any vaccine component or with previous influenza vaccine doses
• People with asthma
• Children or adolescents on long-term aspirin treatment.
• Children and adults suffering from chronic lung disease, cardiovascular (except for hypertension), kidney, liver, neurological/neuromuscular, haematological, or metabolic disorders
• Immunosuppressed children and adults (including immunosuppression caused by drugs or by HIV)
• Pregnant women

In a comprehensive recommendation for generalized vaccination in the United States, the Centers for Disease Control and Prevention (CDC), which began recommending influenza vaccines to health care workers in 1981, emphasized to physicians the importance of special vaccinations for members of certain vulnerable groups. , and their caregivers:

Vaccinations are especially important for people at high risk of serious complications of influenza or people living with or caring for people at high risk for serious complications. In 2009, a new high-dose formulation of the standard influenza vaccine was approved. High Dose Fluzone specifically for people aged 65 years and over; the difference is that it has four times the standard Fluzone antigen dose.

The US government requires hospitals to report on vaccination rates for workers. Several US states and hundreds of US hospitals require health workers to get vaccinated or wear masks during the flu season. These requirements sometimes lead to union lawsuits at narrow collective bargaining places, but supporters note that courts generally support enforced vaccination laws affecting the general population during disease outbreaks.

Vaccination against influenza is very important for members of high-risk groups who are likely to have complications from influenza, such as pregnant women and children and adolescents from six months to 18 years;

• In increasing the age limit of up to 18 years, the goal is to reduce the time children and parents lose from visits to pediatricians and missing schools and antibiotic needs for complications
• An additional benefit expected from childhood vaccination is the reduced number of influenza cases among parents and other household members, and possibly spread to the general public.

In the United States: CDC has indicated that live attenuated influenza vaccine (LAIV), also called nasal spray vaccine, is not recommended for flu season 2016-2017, in the United States.

Furthermore, health care personnel caring for people with severe immune disorders should receive injections (TIV or QIV) rather than LAIV.

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Absorb

In risky group

The uptake of flu vaccination, both seasonal and pandemic, is often low. A systematic review of the absorption of flu pandemic vaccination has identified several personal factors that may affect the taking, including sex (higher uptake in men), ethnicity (higher in people of ethnic minorities) and have chronic illnesses. Confidence in the safety and effectiveness of vaccines is also important.

Health worker

Front-line health care is often recommended for seasonal flu and pandemic vaccinations. For example, in the UK all healthcare workers involved in patient care are recommended to receive seasonal flu vaccines, and are also recommended to be vaccinated against H1N1/09 (later renamed A (H1N1) pdm09) during the 2009 pandemic. However, the uptake is often low. During the 2009 pandemic, low uptake by healthcare workers was seen in countries including Britain, Italy, Greece and Hong Kong.

In the 2010 survey of health care workers of the United States, 63.5% reported that they received the flu vaccine during the 2010-11 season, an increase of 61.9% reporting the previous season. US Health Professionals with direct patient contact had higher vaccination uptake, such as doctors and dentists (84.2%) and nursing practitioners (82.6%).

The main reason for vaccinating healthcare workers is preventing staff from spreading the flu to their patients and reducing staff absenteeism when service demand is high, but the reason healthcare workers declare their decision to accept or reject vaccinations may be more often done with perceived personal benefits.

In Victoria (Australia) general hospital, the rate of vaccination of health workers in 2005 ranged from 34% for non-clinical staff to 42% for laboratory staff. One reason for rejecting a vaccine is a concern for adverse reactions; In one study, 31% of resident doctors at the hospital's education mistakenly believed the Australian vaccine could cause influenza.

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Manufacturing

A flu vaccine is usually grown by a vaccine manufacturer in a fertilized chicken egg. In the Northern Hemisphere, the manufacturing process begins after the announcement (usually in February) of the WHO strain suggested for the winter flu season. Three strains (representing H1N1, H3N2, and strain B) flu were selected and the chicken eggs inoculated separately, the monovalent harvest was then combined to make the trivalent vaccine.

In November 2007, both conventional injections and nasal sprays were produced using chicken eggs. The EU has also approved Optaflu, a vaccine produced by Novartis using an animal cell vat. This technique is expected to be more measurable and avoid problems with eggs, such as allergic reactions and incompatibility with strains that affect avians like chickens. Research continues into the idea of ​​a "universal" influenza vaccine that does not require adjustment for certain strains, but will be effective against many types of influenza viruses. However, no vaccine candidate was announced in November 2007.

DNA-based vaccination, which is expected to be faster to produce, is in 2011 in clinical trials, determining safety and efficacy.

On Nov. 20, Novartis received FDA approval for the first cell culture vaccine.

In a 2007 report, the global capacity of about 826 million spores of seasonal (inactive and live) influenza vaccines doubled the production of 413 Ã, million doses. In an aggressive scenario of producing pandemic influenza vaccines in 2013, only 2.8 Ã, billion programs can be produced within six months. If all middle-income countries look up vaccines for their entire population in a pandemic, almost 2 billion will be required. If China pursues this goal too, more than 3 billion courses will be needed to serve this population. Vaccine research and development is underway to identify new vaccine approaches that can produce vaccines in large quantities at prices affordable to the global population.

The method of making vaccines that cut the need for eggs includes the development of particles similar to influenza virus (VLP). VLPs resemble viruses, but do not need inactivation, because they do not include the virus coding element, but only present the antigen in a similar way to the virion. Some methods produce VLP including insect cell culture Spodoptera frugiperda Sf9 and production of plant-based vaccines (eg, Production at Nicotiana benthamiana ). There is evidence that some VLPs cause antibodies that recognize wider panels of different antigenicase virus antigens compared with other vaccines in the hemagglutination-inhibition test (HIA).

Influenza vaccine is produced in pathogen-free eggs that are 11 to 12 days old. The top of the egg is disinfected by wiping it with alcohol and then the egg is wound to identify a non-veinous area in the allantoic cavity where a small hole is pierced to act as a pressure release. The second hole is made at the top of the egg, where the influenza virus is injected into the allantoic cavity, passing through the corioalanto membrane. The two holes were then covered with liquid paraffin and the inoculated egg was incubated for 48 hours at 37 degrees Celsius. During the incubation period, replicating virus and newly replicated virus are released into the allantoic fluid

After 48 hours of incubation period, the top of the cracked egg and 10 milliliters of aloisois fluid are removed, from which about 15 micrograms of flu vaccine can be obtained. At this point, the virus has been weakened or killed and the viral antigen is purified and placed in a vial, syringe, or nasal spray. Completed on a large scale, this method is used to produce flu vaccines for human populations.

Annual reform

Each year, three strains are selected for selection in this year's flu vaccination by the WHO Global Influenza Surveillance Network. The selected strains are H1N1, H3N2, and Type-B strains that are thought to be most likely to cause significant human suffering in the upcoming season. Beginning with the Northern Hurricane season 2012-2013 (coinciding with the approval of the quadrivalent influenza vaccine), WHO also recommends a second B strain for use in quadrivalent vaccines. The World Health Organization coordinates vaccine content annually to contain the most likely strain of virus next year.

"The WHO Global Influenza Surveillance Network was established in 1952. The network consists of four WHO Collaboration Centers (CC WHO) and 112 institutions in 83 countries, recognized by WHO as WHO National Influenza Centers (NICs).NIC these collect specimens in their country, perform primary viral isolation and early antigenic characterization. They transmit newly isolated strains to the WHO CC for high-level antigenic and genetic analysis, the results on which the WHO recommendation on the influenza vaccine composition for the Northern and Southern Hemispaces year. "

The selection of the Influenza Surveillance Network Global virus for the vaccine-making process is based on the best estimate of which strain will dominate next year, which will ultimately provide a good but inviolable estimate.

The WHO's official recommendation was first issued in 1973. In early 1999 there were two recommendations per year: one for the northern hemisphere (N) and the other for the southern hemisphere (S).

The annual historical reformulation of the influenza vaccine is listed in a separate article. Recommendation of WHO's latest seasonal influenza vaccine composition:

2016 Hemisphere Southern Hemisphere season

The composition of the viral vaccine for use in the Southern Hemisphere Southern influenza season recommended by the World Health Organization on September 24, 2015 is:

• A/California/7/2009 (H1N1) viruses like pdm09
• A/Hong Kong/4801/2014 (like H3N2)
virus
• B/Brisbane/60/2008-like virus

WHO recommends that quadrivalent vaccines containing two influenza B viruses should contain the above three viruses and B/Phuket/3073/2013-like viruses.

2016-2017 Northern Hemisphere Season

The composition of the trivalent viral vaccine for use in the Northern Hemisphere 2016-2017 season recommended by the World Health Organization on 25 February 2016 is:

• A/California/7/2009 (H1N1) viruses like pdm09
• A/Hong Kong/4801/2014 (like H3N2)
virus
• B/Brisbane/60/2008-like virus

WHO recommends that a quadrivalent vaccine containing two influenza B viruses contain the above three viruses and B/Phuket/3073/2013-like viruses.

2017 Hemisphere Southern Hemisphere

The composition of the viral vaccine for use in the 2017 Hemisphere influenza season recommended by the World Health Organization on 29 September 2016 is:

• A/Michigan/45/2015 (H1N1) viruses like pdm09
• A/Hong Kong/4801/2014 (like H3N2)
virus
• B/Brisbane/60/2008-like virus

WHO recommends that quadrivalent vaccines containing two influenza B viruses should contain the above three viruses and B/Phuket/3073/2013-like viruses.

The Southern Hemisphere is experiencing "poor vaccine effectiveness" against H3N2 this season.

2017-2018 Northern Hemisphere Season

The composition of the trivalent viral vaccine for use in the Northern Hemisphere season 2017-2018 season recommended by the Immunization Practices Advisory Committee on 25 August 2017 is:

• A/Michigan/45/2015 (H1N1) viruses like pdm09
• A/Hong Kong/4801/2014 (like H3N2)
virus
• B/Brisbane/60/2008-like virus (Victorian lineage)

In addition to these components, the quadrivalent vaccine will also include B/Phuket virus/3073/2013-like (Yamagata lineage).

In California, some emergency systems are plagued by surges in H3N2 flu cases. In addition, some areas have local oseltamivir deficiency. The severity of the flu season looks somewhat comparable to the 2009-10 swine flu outbreak. The February 2018 CDC interim report estimated the effectiveness of the vaccine to 25% against H3N2, 67% against H1N1, and 42% against influenza B.

2018 Hemisphere Southern Hemisphere Season

The composition of the viral vaccine for use in the 2018 Southern Hemisphere season recommended by the World Health Organization on September 28, 2017 is:

• A/Michigan/45/2015 (H1N1) viruses like pdm09
• A/Singapore/INFIMH-16-0019/2016 (H3N2) virus-like
• B/Phuket/3073/2013-like virus

WHO recommends that quadrivalent vaccines containing two influenza B viruses should contain the above three viruses and B/Brisbane/60/2008 viruses.

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History

Vaccines are used in both humans and non-humans. The human vaccine is intended unless specifically identified as an animal, poultry or livestock vaccine.

Origin and development

In a Spanish flu pandemic worldwide in 1918, "Doctors try everything they know, everything they've heard, from the ancient art of bleeding patients, to deliver oxygen, to develop new vaccines and sera (especially against what we now call Hemophilus influenzae - a name derived from the fact that it was originally thought of as an etiologic agent - and some types of pneumococcus). Only one therapeutic action, blood transfusion from the recovered patient to new victim, suggests the presence of a successful clue. "

In 1931, the growth of the virus in the hens eggs that had been bred was reported by Ernest William Goodpasture and colleagues at Vanderbilt University. The work was extended to the growth of influenza viruses by several workers, including Thomas Francis, Jonas Salk, Wilson Wilson and Macfarlane Burnet, leading to the first experimental influenza vaccine. In the 1940s, the US military developed the first approved inactivated vaccine for influenza, used in the Second World War. Hen eggs continue to be used to produce viruses used in influenza vaccines, but producers make improvements in viral purity by developing better processes to remove egg proteins and to reduce systemic reactivity of the vaccine. Recently, the US FDA approved an influenza vaccine made by a virus that grows in cell culture and an influenza vaccine made from recombinant protein has been approved, with a plant-based influenza vaccine tested in clinical trials.

Reception

According to the CDC: "Influenza vaccination is the primary method to prevent influenza and severe complications.Vaccination is associated with influenza-related respiratory illness and physician visits among all age groups, hospitalization and deaths among people at high risk, otitis media in between children, and absenteeism among adults.Although the rate of influenza vaccination increased substantially during the 1990s, further improvement in vaccine coverage rates was required.

Egg-based technology (still used in 2005) to produce influenza vaccines was created in the 1950s. In the fear of the US swine flu of 1976, President Gerald Ford was confronted with a potential swine flu pandemic. Vaccination programs are in a hurry, but are overwhelmed by issues of delays and public relations. Meanwhile, maximum military detention attempts unexpectedly succeed in limiting the new tension to a single military base from which it originated. At the base a number of soldiers fell seriously ill, but only one died. The program was canceled, after about 24% of the population had received the vaccination. The advantages in deaths twenty-five more than the normal annual rate as well as 400 excessive hospitalizations, both from the Guillain-Barrà © Å © syndrome, are thought to have occurred from the vaccination program itself, which illustrates that the vaccine itself is not risk-free. The results have been cited to spark the remaining doubts about vaccinations. Ultimately, however, even a vilable 1976 vaccine could save lives. A 2010 study found a significantly increased immune response to the 2009 pandemic H1N1 in study participants who had received vaccinations against swine flu in 1976.

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Society and culture

Evidence of evidence

Tom Jefferson, who has headed the Cochrane Collaboration review of the flu vaccine, has called clinical evidence of a "junk" flu vaccine and hence says they are ineffective; she has called for a placebo-controlled, randomized clinical trial. His views on clinical trials are considered unethical by mainstream medicine and his views on the efficacy of vaccines are rejected by medical institutions including the CDC and National Institutes of Health, and by key figures in the field such as Anthony Fauci.

Michael Osterholm who has led the Infectious Disease Research Center and Policy 2012 review of flu vaccines recommends getting the vaccine but criticizing his promotion "We have overpromoted and overhyped this vaccine... it does not protect because it is promoted. : it's all public relations ".

Cost effectiveness

The cost effectiveness of seasonal influenza vaccinations has been widely evaluated for different groups and in different settings. In the elderly (over the age of 65) the majority of published studies have found that vaccination is cost-saving, with the cost savings associated with influenza vaccination (eg preventable health care visits) exceeding the cost of vaccination. In older adults (ages 50-64), some published studies have found that influenza vaccinations may be cost-effective, but the results of this study are often found to depend on the main assumptions used in the economic evaluation. Uncertainty in influenza cost effectiveness models can in part be explained by the complexities involved in estimating disease burden, as well as seasonal variability in circulating strains and vaccine matches. In healthy working adults (aged 18-49 years), a 2012 review found that vaccination generally does not save costs, with suitability for funding depending on the willingness to pay for related health benefits. In children, the majority of studies have found that influenza vaccination is cost-effective, but many studies include an (indirect) increase in productivity, which may not be given the same weight in all settings. Several studies have tried to predict the cost-effectiveness of interventions (including pre-pregnancy vaccination) to help protect against future pandemics, but predict cost-effectiveness has been complicated by uncertainty about the future severity of future pandemic potential and efficacy of action. against it.

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Research

Influenza studies include molecular virology, molecular evolution, pathogenesis, host immune response, genomics, and epidemiology. It helps in developing influenza handling such as vaccines, therapies and diagnostic tools. An improved influenza response requires basic research on how viruses enter cells, replicate, mutate, evolve into new strains and induce an immune response. The Influenza Genome Sequencing Project makes an influenza series library that will help us understand what makes one strain more deadly than another, what genetic determinants most affect immunogenicity, and how the virus evolves over time. Solutions to limitations in vaccine methods are currently being investigated.

Different approaches use Internet content to estimate the impact of influenza vaccination campaigns. More specifically, researchers have used data from Twitter and Microsoft Bing (search engines), and proposed a statistical framework that, after a series of operations, mapped this information to estimate the percentage reduction of diseases such as influenza in various fields, where vaccinations have been performed. do. This method has been used to measure the impact of two flu vaccination programs in the UK (2013/14 and 2014/15), in which school-age children are given live-attenuated influenza vaccines (LAIV). In particular, the impact estimates are consistent with estimates from Public Health England based on the endpoint of traditional syndrome surveillance.

Rapid response to pandemic flu

The rapid development, production and distribution of pandemic influenza vaccines has the potential to save millions of lives during an influenza pandemic. Due to the short span of time between the identification of pandemic strains and the need for vaccination, researchers are looking for new technologies for vaccine production that can provide better and more affordable "real-time" access, thus increasing access for people living in low places. - and middle-income countries, where influenza pandemics may originate, such as direct attenuated (egg-based or cell-based) technologies and recombinant technologies (proteins and virus-like particles). As of July 2009, more than 70 known clinical trials have been completed or are underway for the influenza pandemic vaccine. In September 2009, the US Food and Drug Administration (FDA) approved four vaccines against the 2009 H1N1 influenza virus (pandemic strain 2009), and expects many initial vaccines to be available within the next month.

Quadrivalent vaccine for seasonal flu

The quadrivalent flu vaccine administered by the nasal fog was approved by the US Food and Drug Administration (FDA) in March 2012. Fluarix Quadrivalent is approved by the FDA in December 2012.

Universal flu vaccine

The "universal vaccine" that does not have to be designed and made for every flu season in each hemisphere would be useful, to stabilize the supply and to ascertain the error in design or escape from the strain circulating through the mutation. Such a vaccine has been the subject of research for decades.

One promising approach is to use broadly neutralizing antibodies that unlike the currently used vaccines, which provoke the body to produce an immune response, but provide a component of the immune response itself. The first neutralizing antibodies were identified in 1993 through experiments; with time the researchers understood that flu neutralizing antibodies bind the stem of the Hemagglutinin protein; researchers then identified antibodies that could bind the head of the protein. Later, the researchers identified a highly preserved M2 proton channel as a potential target for broadly neutralizing antibodies.

The challenge for researchers has been to identify single antibodies that can neutralize many subtypes of the virus, so they can be useful in every season, and that target preserves domains that are resistant to antigenic drift.

Another approach has taken the conserved domains identified from these projects, and sends these antigen groups to provoke immune responses; various approaches with different antigens, presented in different ways (as fusion proteins, mounted on virus-like particles, in non-pathogenic viruses, such as DNA, etc.), are under development.

Efforts have also been made to develop a universal vaccine that specifically activates T-cell responses, based on clinical data showing that people with strong initial T cell responses have better results when infected with influenza and because T cells respond to the epitope preserved.. The challenge for developers is that these epitopes are in the domain of a few immunogenic internal proteins.

Along with the rest of the vaccine field, people working on the universal vaccine have experimented with adjuvant vaccines to improve their vaccine ability to create a strong and lasting immune response.

src: www.ufmcpueblo.com

Veterinary use

"Vaccination in the veterinary world pursues four objectives: (i) protection from clinical illness, (ii) protection from viral infections, (iii) protection from viral excretion, and (iv) infectious serologic differentiation of vaccinated animals (so-called DIVA principles.) In the field of influenza vaccination, both commercially available and experimental-tested vaccines have been shown so far to meet all these requirements. "

Horse

Horses with horse flu can have fever, dry cough, runny nose, and become depressed and reluctant to eat or drink for several days but usually heal within two to three weeks. "The vaccination schedule generally requires two dose main courses, 3-6 weeks apart, followed by boosters at 6-12 months intervals.It is generally recognized that in many cases these schedules may not maintain antibodies and administration levels more often are advised in risky situations high. "

It is a general requirement at an exhibition in England that horses vaccinated against equine flu and vaccination cards should be produced; The International Federation for Equestrian Sports (FEI) requires vaccinations every six months.

Poultry

Fowl vaccines for avian influenza are made cheaply and are not filtered and purified like human vaccines to remove little bacteria or other viruses. They usually contain an entire virus, not just hemagglutinin as in most human flu vaccines. Another difference between human and poultry vaccines is a rejuvenated poultry vaccine with mineral oil, which induces a strong immune reaction but can cause inflammation and abscesses. "Chicken vaccinators that accidentally thrust themselves have developed painful or even loss of fingers, doctors say.The effectiveness may also be limited.The chicken vaccine is often just similar to the circulating flu strain - some contain isolated H5N2 strains in Mexico last year... 'With chickens, if you use a vaccine that is only 85% connected, you will get protection,' says Dr. Cardona. 'In humans, you can get a point of mutation, and vaccine that 99.99 Ã, related percent will not protect you.'And they are weaker [than human vaccines]. "Chickens are smaller and you only need to protect them for six weeks, because that's how long they live until you eat them, "says Dr. John J. Treanor, a vaccine expert at the University of Rochester.The human seasonal flu vaccine contains about 45 micrograms of antigen, while experimental vaccine al A (H5N1) contains 180. Chicken vaccine may contain less than one microgram. 'You have to be careful in extrapolating data from birds to humans,' warns Dr. David E. Swayne, director of the Southeast Poultry Research Laboratory of the agricultural department. 'Birds are more closely related to dinosaurs.' "

The researchers, led by Nicholas Savill of the University of Edinburgh in Scotland, used a mathematical model to simulate the spread of H5N1 and concluded that "at least 95 Ã,/span> percent of birds need to be protected to prevent the spread of the virus." In practice, it is difficult to protect more than 90 percent of the flock, the level of protection achieved by vaccines is usually much lower than this. "The UN Food and Agriculture Organization has issued recommendations on the prevention and control of avian influenza in poultry, including the use of vaccinations.

The filtered and purified influenza A vaccine for humans is being developed and many countries have recommended it to be stockpiled so that if an Avian influenza pandemic starts jumping into humans, vaccines can be quickly given to avoid fatalities. Avian influenza is sometimes called bird flu, and is generally avian influenza.

Pig

Swine influenza vaccine is widely used in pig farms in Europe and North America. Most swine flu vaccines include H1N1 and H3N2 strains.

Swine influenza pigs have been recognized as a major problem since the outbreak in 1976. Viral evolution has resulted in inconsistent responses to traditional vaccines. The standard commercial swine flu vaccine is effective in controlling problems when viral strains are suitable enough to have significant cross-protection. An autogenous vaccine made from certain viruses isolated, made and used in more difficult cases. Novartis vaccine producers claim that the H3N2 strain (first identified in 1998) has brought huge losses to pig farmers. An abortion storm is a common sign and the mother pig stops eating for a few days and the fever is high. The mortality rate can be as high as 15 percent.

Dog

In 2004, influenza A H3N8 virus subtype was found to cause influenza canines. Due to lack of prior exposure to this virus, dogs have no natural resistance to this virus. However, vaccines are now available.

src: pediatrics.aappublications.org

Note

src: i.ytimg.com

References

src: www.healthline.com

External links

• PATH Resources Library Resource Library PATH
• Vaccine Information Statement Vaccine Information Enabled CDC
• Preventable Vaccines and Diseases - Seasonal Influenza Vaccination (Flu)
• Misunderstanding of Influenza and Seasonal Influenza Vaccines

Source of the article : Wikipedia