FluMist

Influenza (Flu)
Types
Avian (A/H5N1 subtype) · Canine Equine · Swine (A/H1N1 subtype)
Vaccines
2009 pandemic (Pandemrix) ACAM-FLU-A · Fluzone · Influvac Live attenuated (FluMist) · Optaflu
Treatment
Amantadine · Arbidol · Laninamivir Oseltamivir · Peramivir · Rimantadine Vitamin D · Zanamivir
Pandemics
2009 Swine · 1968–1969 Hong Kong · 1918
Outbreaks
2008 West Bengal 2007 Bernard Matthews H5N1 2007 Australian equine 2006 H5N1 India · 1976 swine flu
See also
Flu season · Influenza evolution Influenza research Influenza-like illness
v · d · e

FluMist is a nasal spray influenza vaccine manufactured by MedImmune, Inc. that was first introduced in 2003.^[1] It was the first and (as of 2007) the only live attenuated vaccine for influenza available outside of Europe.^[2] It is also called live attenuated influenza vaccine (LAIV).^[3] In September 2009 a LAIV intranasal vaccine for the novel H1N1 influenza virus was approved.^[4] In 2011, the vaccine was approved by the European Medicines Agency for use in the European Union under the name Fluenz.^[5]

Groups for whom FluMist is recommended

Influenza vaccine is a cost-effective counter-measure to the threat of seasonal or pandemic outbreaks of influenza.^[6][7]

In Canada, the National Advisory Committee on Immunization (NACI), the group that advises the Public Health Agency of Canada, currently recommends that everyone aged 2 to 64 years be encouraged to receive annual influenza vaccination, and that children between the age of 6 and 24 months, and their household contacts, should be considered a high priority for the flu vaccine.^[8]

In February 2008, the U.S. Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) recommended vaccination for all children and teenagers between six months and 18 years of age.^[8]

FluMist is a vaccine of demonstrated effectiveness against seasonal influenza.^[3] Reviews conducted in 2008^[9] and 2011^[10] suggest that FluMist may be equal to or more effective than injected influenza vaccines in children aged 6–71 months and in children aged 6–17 years.

In 2007, FluMist received additional approval from the U.S. Food and Drug Administration (FDA) extending the age groups it is approved for, to include healthy children two years old and onward.^[11] And the CDC's Advisory Committee on Immunization Practices (ACIP), endorsed the needle-free vaccine as a good option for healthy (non-asthmatic) children aged 2 through 4 years.^[12] This extended approval supplemented approvals for children over four years of age that were already effective. The sum of these approvals is that FluMist is approved and recommended from the child's 25th month through the adult's 49th year of age.

FluMist is currently recommended for all healthy persons at least two years old and under 50 years of age wishing to protect themselves from influenza and its complications, or to avoid spreading the flu to members of certain vulnerable groups:

"All healthy, non-pregnant persons age 49 yrs and younger who want to reduce the likelihood of becoming ill with influenza, or of spreading it to others who meet any of the criteria listed below:

-Working or living with at-risk people as listed in the section above.

-Healthcare personnel or other persons who provide direct care to at-risk people (except persons in close contact with severely immunosuppressed persons).

-Household contacts and out-of-home caregivers of children age 0–59m.

-Travelers who may be among people from areas of the world where there is current influenza activity (e.g., on organized tours).

-Students or other persons in institutional settings (e.g., dormitory residents)." ^[13]

For comparison, only Sanofi-Aventis's injectable influenza vaccine is approved for children 7 months of age and older; FluMist is approved after the second year, and other injectable vaccines from four years of age onward. Injectable influenza vaccine approvals have no upper age limit, while FluMist has not yet been tested or presented for FDA approval for use by persons 50 or older.

Within the age groups they are approved for, injectable vaccines do occasionally present mild side effects such as soreness, redness, swelling, fever, and aches, and FluMist sometimes causes brief and mild symptoms such as a runny nose. Side effects of both FluMist and injected vaccines tend to be slightly more prevalent the first year, and to diminish with vaccinations given in subsequent years.^[14]

Tests against injected (killed virus) vaccinations have shown that FluMist is more effective than needle shots in preventing influenza, especially in children aged 6 to 17^[15][16] but one smaller study in adults showed lower effectiveness against influenza B viruses in adults.^[17]

In past years when flu vaccine has been in short supply, healthy people were requested to abstain from vaccination early in the season, to leave the limited supply for the most vulnerable groups. Flu vaccine supplies are now abundant, and since healthy people benefit from vaccination they are now encouraged to protect themselves and others by being vaccinated.

The 2007 recommendations by the US Advisory Committee on Immunization Practices (ACIP) include six principal changes or updates. These stress that all persons who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others should be vaccinated, and that young children not previously vaccinated should be vaccinated twice, and include these specific recommendations:

ACIP reiterates a previous recommendation that all persons, including school-aged children, who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others should be vaccinated (see Box and Recommendations for Using TIV and LAIV During the 2007--08 Influenza Season).

ACIP emphasizes that immunization providers should offer influenza vaccine and schedule immunization clinics throughout the influenza season (see Timing of Vaccination).

ACIP recommends that health-care administrators consider the level of vaccination coverage among health-care personnel (HCP) to be one measure of a patient safety quality program and implement policies to encourage HCP vaccination (e.g., obtaining signed statements from HCP who decline influenza vaccination) (see Additional Information Regarding Vaccination of Specific Populations).^[18]

In 2000, a study found FluMist be well tolerated in 57 adults with asymptomatic HIV and median CD4 counts of 541.^[19] The FluMist patient information further clarifies, "Although FluMist was studied in 57 asymptomatic or mildly symptomatic adults with HIV infection [...], data supporting the safety and effectiveness of FluMist administration in immunocompromised individuals are limited."^[20] In 2008, FluMist was tested and found safe for children suffering from HIV and taking anti-retrovirals.^{[21][dead link]}

However, the U.S. Centers for Disease Control state clearly that people with HIV/AIDS should not receive FluMist ^[22] and that advice is augmented by the suggestion that close household contacts or caregivers of severely immunocompromised individuals should not receive FluMist due to transmission risks from individuals immunized with FluMist.

The vaccine was approved for use in the European Union by the European Medicines Agency in 2011. Marketing approval in Europe, where it will be called Fluenz, is for the prevention of seasonal influenza in children aged from two to less than 18 years,^[23] though distribution will not likely begin until 2012.^[5]

Groups for whom FluMist is not recommended

• People less than 2 years of age^[3]
• People 50 years of age and over^[3]
• People with a medical condition that places them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airways disease
• People with medical conditions such as diabetes or kidney failure or people with illnesses that weaken the immune system, or who take medications that can weaken the immune system
• Children less than 5 years old with a history of recurrent wheezing
• Children or adolescents receiving aspirin
• People with a history of Guillain-Barré syndrome, a rare disorder of the nervous system
• Pregnant women
• People who have a severe allergy to chicken eggs or who are allergic to any of the nasal spray vaccine components^[3]

It is possible for individuals vaccinated with FluMist to spread the virus to others for up to 21 days after vaccination. For this reason it is recommended that those vaccinated with FluMist avoid close contact with individuals with weak immune systems during that time.^[24]

Testing pandemic FluMist variants

FluMist is designed to be quickly modifiable to present the surface antigens of seasonal flu. The modifiability could also allow it to be quickly customized as a vaccine against a pandemic influenza if one were to emerge. In light of the Global spread of H5N1 advance preparation to reduce human mortality in the event of an H5N1 pandemic has begun. Modifying FluMist to serve as a specific human H5N1 vaccine is among the measures studied.^[25]

In June 2006, the National Institutes of Health (NIH) began enrolling participants in a Phase 1 H5N1 study of an intranasal influenza vaccine candidate based on MedImmune's live, attenuated vaccine technology.^[26]

In September 2006 the NIH NIAID reported that inoculation with a FluMist vaccine modified to present the surface antigens of certain H5N1 variants provided broad protection against other H5N1 variants in the mouse and ferret models.^[27] Attenuated live viruses were found protective against H5N1 in mice and chickens in a 2009 study.^[28]

Although early work is focusing 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 strains of influenza, ready to be grafted onto the base attenuated FluMist core virus whenever a pandemic threat might emerge.

"Several trials have reported that LAIVs can boost virus-specific CTLs as well as mucosal and serum antibodies and provide broad cross-protection against heterologous human influenza A viruses." (58, 59)^[29] "[V]accine formulas inducing heterosubtypic T cell–mediated immunity may confer broad protection against avian and human influenza A viruses." ^[29]

In September 2009 a LAIV intranasal vaccine for the novel H1N1 influenza virus was approved.^[4]

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 later by Aviron, in Mountain View, California, under the sponsorship of NIH in the mid-1990s. MedImmune, Inc. purchased Aviron in 2002, and the FDA approved FluMist in June 2003.^[30] FluMist was first made available in September 2003.

The U.S. FDA initially approved FluMist only for healthy people ages 5 to 49 because of concerns over possible side effects. Now FluMist is approved and recommended for healthy children 24 months of age and older. The FDA approved the current unfrozen refrigerated version for the same age group (ages 5–49) in August 2006 following completion of phase 3 clinical trials.^[31] CAIV-T has been approved by the FDA and is the version offered on the market beginning in fall of 2007.

The current version of the vaccine is called CAIV-T, and is stable for storage in a refrigerator, rather than requiring freezer storage as did the originally-approved formulation. Approved for the 2007-2008 flu season, the refrigerated formulation can be distributed more economically, so that the price differential with shots (which had hampered sales of the original frozen version of FluMist) is now largely eliminated. FluMist was initially priced higher than the injectable vaccines, but sold only 500,000 of the 4 million doses it produced its first year on the market, despite a comparative shortage of flu vaccine in fall 2004.^[32] The price was sharply lowered the next year, and the company reports distributing 1.6 million doses in 2005.^[33] Because of the price drop, despite selling almost three times as many doses in 2005, the company reported $21 million in FluMist sales, compared to $48 million the previous year.^[34] Further cuts in pricing had to await FDA approval of a refrigerator-cooled FluMist formulation, as the initial formulation required freezer storage and thawing on demand before administration. Although it is positioned as a premium product, the remaining price premium for FluMist over the cost of needle-injected vaccine is small.^{[citation needed]}

References

1. ^ Midthun, Karen; Steven Masiello (2003-07-17). "CBER Approval Letter, Influenza Virus Vaccine, Live, Intranasal (FluMist)". U.S. Food and Drug Administration. Archived from the original on September 29, 2007. http://web.archive.org/web/20070929154324/http%3A//www.fda.gov/cber/approvltr/inflmed061703L.htm. Retrieved 2008-07-06. 
2. ^ http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5213a1.htm Recommendations and Reports September 26, 2003 / 52(RR13);1-8 Using Live, Attenuated Influenza Vaccine for Prevention and Control of Influenza Supplemental Recommendations of the Advisory Committee on Immunization Practices (ACIP) Prepared by Scott A. Harper, M.D.1 Keiji Fukuda, M.D.1 Nancy J. Cox, Ph.D.1 Carolyn B. Bridges, M.D.2 1Division of Viral and Rickettsial Diseases National Center for Infectious Diseases 2Epidemiology and Surveillance Division National Immunization Program
3. ^ ^{a b c d e} "The Nasal-Spray Flu Vaccine (Live Attenuated Influenza Vaccine [LAIV])". National Center for Immunization and Respiratory Diseases. 2008-01-22. http://www.cdc.gov/flu/about/qa/nasalspray.htm. Retrieved 2008-07-06. 
4. ^ ^{a b} "Update on Influenza A (H1N1) 2009 Monovalent Vaccines". October 9, 2009. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5839a3.htm. Retrieved October 23, 2009. 
5. ^ ^{a b} AstraZeneca's Nasal Flu Vaccine Approved In Europe
6. ^ "Comparisons of LAIV and TAIV Efficacy". National Center for Immunization and Respiratory Diseases. 2007-10-26. http://www.cdc.gov/flu/professionals/acip/efficacycomparison.htm. Retrieved 2008-07-06. "Neither the comparative advantages of FluMist in the first study nor the apparent advantages of needle-injected vaccine in the second rose to statistical significance." 
7. ^ Bright, Rick; Donald Carter, Corey Crevar, Franklin Toapanta, Jonathan Steckbeck, Kelly Cole, Niranjan Kumar, Peter Pushko, Gale Smith, Terrence Tumpey and Ted Ross (January 2008). Rodrigues, Mauricio. ed. "Cross-Clade Protective Immune Responses to Influenza Viruses with H5N1 HA and NA Elicited by an Influenza Virus-Like Particle". PLoS ONE (Public Library of Science) 3 (1): e1501. doi:10.1371/journal.pone.0001501. PMC 2200794. PMID 18231588. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2200794. 
8. ^ ^{a b} "U.S. panel recommends all kids get the flu shot". CTV.ca. 2008-02-27. http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20080227/flu_shot_080226/20080227. Retrieved 2008-07-06. 
9. ^ Rhorer J, Ambrose CS, Dickinson S, et al. (February 2009). "Efficacy of live attenuated influenza vaccine in children: A meta-analysis of nine randomized clinical trials". Vaccine 27 (7): 1101–10. doi:10.1016/j.vaccine.2008.11.093. PMID 19095024. 
10. ^ http://www.medscape.com/viewarticle/741036 Christopher S. Ambrose; Myron J. Levin; Robert B. Belshe The Relative Efficacy of Trivalent Live Attenuated and Inactivated Influenza Vaccines in Children and Adults 04/25/2011; Influenza Resp Viruses. 2011;5(2):67-75 Influenza Other Respi Viruses. 2011 March; 5(2): 67–75 PMID 21306569; PMCID PMC3151550; Free PMC Article http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3151550/ doi: 10.1111/j.1750-2659.2010.00183.x
11. ^ http://www.fda.gov/bbs/topics/NEWS/2007/NEW01705.html FDA Approves Nasal Influenza Vaccine for Use in Younger Children
12. ^ CIDRAP >> ACIP endorses FluMist for 2-, 3-, and 4-year-olds
13. ^ http://www.immunize.org/catg.d/p2011.pdf Summary of Recommendations for Adult Immunization linked from CDC website http://www.cdc.gov/vaccines/recs/schedules/adult-schedule.htm#print
14. ^ Ohmit SE, Gross J, Victor JC, Monto AS (February 2009). "Reduced Reaction Frequencies with Repeated Inactivated or Live-attenuated Influenza Vaccination". Vaccine 27 (7): 1050–4. doi:10.1016/j.vaccine.2008.11.100. PMC 2665993. PMID 19095028. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2665993. 
15. ^ FluMist More Effective Than Injections For Small Children And Babies. Medical News Today. 1 May 2006.
16. ^ 'FluMist MedImmune clinical data (phase III) (influenza).' R&D Focus Drug News 30 January 2006.
17. ^ Study: Flu Shots Better Than FluMist. cbsnews.com. 13 December 2006.
18. ^ Primary Changes and Updates in the Recommendations (2007) http://www.cdc.gov/MMWR/preview/mmwrhtml/rr5606a1.htm
19. ^ http://www.journals.uchicago.edu/doi/abs/10.1086/315246 Comparison of the Safety, Vaccine Virus Shedding, and Immunogenicity of Influenza Virus Vaccine, Trivalent, Types A and B, Live Cold-Adapted, Administered to Human Immunodeficiency Virus (HIV)–Infected and Non–HIV-Infected Adults James C. King, Jr.,1 John Treanor,4 Patricia E. Fast,5 Mark Wolff,2 Lihan Yan,2 Dominic Iacuzio,3,a Bernard Readmond,1 Diane O'Brien,4 Kenneth Mallon,5 William E. Highsmith,1 John S. Lambert,1 and Robert B. Belshe6 http://www.journals.uchicago.edu/doi/abs/10.1086/315246
20. ^ 5.4 Altered Immunocompetence, http://www.medimmune.com/pdf/products/flumist_pi.pdf
21. ^ New Research Finds Live Influenza Vaccine is Just as Safe for HIV-Infected Children – Current Recommendation Has Been for Inactivated Vaccine http://www.uchsc.edu/news/newsrelease/2008/jul/vaccine.htm^{[dead link]}
22. ^ Seasonal Influenza (Flu): HIV/AIDS and the Flu http://www.cdc.gov/flu/protect/hiv-flu.htm
23. ^ Fluenz: EPAR - Summary for the public
24. ^ "Risks of FluMist Vaccine". http://www.vaccineinfo.net/immunization/vaccine/influenza/flumist_vaccine_risks.shtml. 
25. ^ See, e.g., http://www.cdc.gov/ncidod/EID/vol12no01/05-1147-G.htm | Volume 12, Number 1, January 2006 Vaccines for Pandemic Influenza Catherine J. Luke* and Kanta Subbarao*
    • National Institutes of Health, Bethesda, Maryland, USA
26. ^ MedImmune Press release MedImmune and National Institutes of Health Begin Clinical Testing of a Live, Attenuated Intranasal Vaccine Against an H5N1 Avian Influenza Virus published June 15, 2006
27. ^ Suguitan, A. L. (2006). [www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030360 "Live, Attenuated Influenza a H5N1 Candidate Vaccines Provide Broad Cross-Protection in Mice and Ferrets"]. PLoS Medicine 3: e360. doi:10.1371/journal.pmed.0030360
28. ^ Steel, J.; Lowen, A. C.; Pena, L.; Angel, M.; Solorzano, A.; Albrecht, R.; Perez, D. R.; Garcia-sastre, A. et al. (2008). "Live Attenuated Influenza Viruses Containing NS1 Truncations as Vaccine Candidates against H5N1 Highly Pathogenic Avian Influenza". Journal of Virology 83: 1742. doi:10.1128/JVI.01920-08.
29. ^ ^{a b} Lee et al. Memory T cells established by seasonal human influenza A infection cross-react with avian influenza A (H5N1) in healthy individuals. Journal of Clinical Investigation, 2008; DOI: 10.1172/JCI32460
30. ^ Appleby, Julie (2004-01-07). "Nasal FluMist overcomes obstacles to reach public". USA Today. http://www.usatoday.com/news/health/2004-01-07-flumist_x.htm. Retrieved 2008-07-06. 
31. ^ "MedImmune begins shipping live intranasal flu vaccine for 2006-2007 after U.S. FDA release". Lab Law Weekly. 2006-08-25. http://www.newsrx.com/newsletters/Lab-Law-Weekly/2006-08-25/08212006333927LL.html. Retrieved 2008-07-06. 
32. ^ Rosenwald, Michael (2005-01-06). "FluMist Sales Falling Short, Survey Finds". The Washington Post: p. E05. http://www.washingtonpost.com/ac2/wp-dyn/A51955-2005Jan5. Retrieved 2008-07-06. 
33. ^ "MedImmune reports revenues of $1.2 billion". Pharma Business Week. 2006-02-27. http://www.newsrx.com/issue_article/Pharma-Business-Week/2006-02-27/02272006333154PB.html. Retrieved 2008-07-06. 
34. ^ Rosenwald, Michael (2006-02-03). "Sales of MedImmune's Flu Vaccine Drop Sharply". The Washington Post: p. D04. http://www.washingtonpost.com/wp-dyn/content/article/2006/02/02/AR2006020202320.html. Retrieved 2008-07-06. 

External links

• FluMist nasal flu vaccine - Official website
• FluMist information on University of Michigan, School of Public Health website
• Live Attenuated Vaccine in Russia presentation on Russian live influenza vaccines since 1961
• CDC Vaccine Information Statement Live, Attenuated Influenza Vaccine
• CDC Vaccine Information Statement 2009 H1N1 LAIV
• Summary of the European public assessment report (EPAR) for Fluenz