Directly attenuated influenza vaccine ( LAIV ) is a type of influenza vaccine in the form of a recommended nasal spray for influenza prevention. In June 2016 the CDC ceased recommending the use of LAIV because its effectiveness has declined between 2013 and 2016, but this recommendation was reversed in February 2018 for influenza season 2018-2019.
This is an inactivated vaccine, unlike most influenza vaccines, which are inactive vaccines. LAIV is given intranasally, while inactivated vaccines are administered by intramuscular injection. LAIV is sold under the trade name FluMist in the United States and Canada, and Fluenz in Europe. FluMist was produced by MedImmune and was first introduced in 2003.
Video Live attenuated influenza vaccine
Medication using
By 2016, the CDC recommends that LAIV not be used for flu season 2016-2017 and instead another type of influenza vaccine is used. This is due to the low effectiveness of this type of vaccine between 2013 and 2016 with ineffective during the 2015-2016 season. A 2012 review found that LAIV prevents influenza in about one in six children under six given to. It is believed to prevent about 50% more flu cases than the flu that was shot in younger children. However, in those aged less than 2 years, the evidence is not clear. Why there seems to be a decrease in unknown effectiveness.
However, in February 2018, the CDC Advisory Committee on Immunization Practices (ACIP) returned the use of LAIV for flu season 2018-2019. Inactivation and recombinant influenza vaccines are no longer favored by ACIPs rather than LAIV.
Contraindications
The use of LAIV is contraindicated, and therefore should not be used, in the following populations:
- child & lt; age 24 months, due to increased risk of wheezing
- individuals with a history of hypersensitivity to previous influenza vaccinations.
- individuals with a history of hypersensitivity, particularly anaphylactic reactions, in eggs, egg proteins, gentamicin, gelatin, or arginine or other ingredients in the formulation
- Persons with medical conditions that place them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airway disease
- People with medical conditions such as diabetes or kidney failure or people with diseases that weaken the immune system, or who take drugs that can weaken the immune system
- Children younger than 5 years with a recurring wheeze history
- Children or adolescents who receive aspirin
- People with a history of Guillain-Barrà © à © syndrome, a rare disorder of the nervous system
- Pregnant women
- People who have severe allergies to chicken eggs or who are allergic to one component of the nasal spray vaccine
Maps Live attenuated influenza vaccine
Risk
Although the virus in LAIV is attenuated (low in virulence), the virus is alive, and can cause complications with complications in people with weakened immune systems or other underlying medical conditions. In 2010, LAIV is recommended only for people aged 2-49 years, and is not recommended for people who have weakened immune systems, for pregnant women, or for people with certain chronic diseases. In contrast, an attenuated virus vaccine does not contain live virus, and can not cause live infection. People who receive LAIV may release a small amount of vaccine virus during the first week. People who make contact with a vaccinated person are not considered at risk unless their immune system is very weak (eg, bone marrow transplant recipient).
History
FluMist was originally developed by Hunein "John" Maassab, Professor of Epidemiology at the University of Michigan School of Public Health in Ann Arbor, Michigan and then by Aviron, in Mountain View, California, under NIH sponsorship in the mid-1990s. MedImmune, Inc. bought Aviron in 2002, and FDA approved FluMist in June 2003. FluMist was first available in September 2003.
The FDA initially approved FluMist only for healthy people aged 5 to 49 years due to concerns about possible side effects. Now FluMist is approved and recommended for healthy children aged 24 months and older. The FDA approved the current freeze-cooling version for the same age group (ages 5-49) in August 2006 after completing phase 3 clinical trials. CAIV-T was approved by the FDA and was the version offered at the start of the market in the fall of 2007.
The current version of the vaccine is called CAIV-T, and is stable for storage in refrigerators, rather than requiring freezer storage as performed on previously approved formulations. Approved for the 2007-2008 flu season, cooling formulations can be distributed more economically, so price differentials with shots (which have stunted the sale of the original FluMist original version) are now largely eliminated. FluMist initially valued higher than injectable vaccines, but sold only 500,000 of the 4 million doses produced in the first year on the market, despite the comparative shortcomings of the flu vaccine in the fall of 2004. Prices dropped sharply the following year, and the company report distributed 1.6 million dose in 2005. Due to falling prices, despite selling nearly three times as many doses in 2005, the company reported $ 21 million in FluMist sales, compared to $ 48 million a year earlier. Further price cuts should wait for FDA approval of cooled refrigerator-cooled FluMist formulations, since the initial formulation required freezer storage and disbursement on demand prior to administration. Although positioned as a premium product, the premium price left for FluMist for the cost of a small syringe injection.
The FDA regulatory pathway for FluMist has been suggested as a possible precedent for phage therapy.
Society and culture
MedImmune is one of the companies that produce LAIV, which is sold under the trade name "FluMist" in the United States and "Fluenz" in Europe. For flu season 2010-2011, FluMist is the only LAIV approved by the FDA for use in the US. All other FDA-approved are the attenuated virus vaccines. In September 2009, the LAIV intranasal vaccine for the newly approved H1N1 influenza virus and seasonal intranasal vaccine was approved by the European Drug Agency for use in the European Union in 2011, although the distribution of the possibility will not begin until 2012.
In 2007, the only other company that holds the LAIV vaccine right is BioDiem Australia. BioDiem licenses the right to private production of vaccines in China to BCHT Biochemical Changchun, which also holds the public rights to production in China sublicensed by the World Health Organization. BCHT plans to market a trivalent LAIV vaccine for H1N1 flu by the end of 2016. The BCHT flu vaccine is one of the few candidates for the WHO prequalification in the near future, reflecting the shift of China's market priorities from the large domestic market to exports. BioDiem also has production licenses to the Serum Institute of India, which holds exclusive licenses for production in Mexico, Argentina, Peru, South Africa, Bangladesh, Bhutan, Nepal, Pakistan and Sri Lanka, and Thai Government Pharmaceutical Office. This is the first and (in 2007) the only live-attenuated vaccine for influenza available outside Europe. In September 2009, the LAIV intranasal vaccine for the newly approved H1N1 influenza virus. In 2011, the vaccine was approved by the European Drug Agency for use in the European Union under the name Fluenz.
Research
FluMist is designed to be quickly modified to present seasonal flu surface antigens. Modifiability can also allow to be quickly adjusted as a vaccine against pandemic influenza if one appears. Given the global spread of H5N1 preparations to reduce human deaths in the event of an H5N1 pandemic has begun. Modifying FluMist to serve as a specific human H5N1 vaccine is one of the measures studied.
In June 2006, the National Institutes of Health (NIH) began enrolling participants in a Phase 1 H5N1 study of intranasal influenza vaccine candidates based on MedImmune's live vaccine technology.
In September 2006 NIH NIAID reported that inoculation with modified FluMist vaccine to present a specific H5N1 variant surface antigen provides extensive protection against other H5N1 variants in mouse and ferret models. The attenuated live virus was found to be protective against H5N1 in mice and chickens in a 2009 study.
Although initial work focuses on the looming H5N1 threat, the CDC team led by Kanta Subbarao and others intends to eventually prepare and store surface antigens for all known influenza strains, ready to be transplanted to the FluMist core virus base that is attenuated whenever there is a threat pandemic. may appear.
"Several trials have reported that LAIVs can increase virus-specific CTLs as well as mucosal and serum antibodies and provide broad cross-protection against heterologous human A human influenza virus." (58, 59) "[V] estimating a formula that stimulates T cell-mediated heterocubial T cell immunity can provide widespread protection against avian and human influenza A viruses."
In September 2009, the LAIV intranasal vaccine for the newly approved H1N1 influenza virus.
References
External links
- FluMist nasal flu vaccine - Official website
- FluMist Information at the University of Michigan, School of Public Health's website
- Weak Vaccines in Russia presentations on Russian live influenza vaccines since 1961
- CDC Live Vaccine Information Statement, Infantile Atheruation vaccine
- CDC 2009 Vaccine Information Report H1N1 LAIV
- Summary of the European public assessment report (EPAR) for Fluenz
- FDA prescribing information
Source of the article : Wikipedia
0 Comments