Influenza vaccine

vaccine against influenza

Influenza vaccines, also known as flu shots or flu jabs, are vaccines that protect against infection by influenza viruses.[1] New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes.[1] While their effectiveness varies from year to year, most provide modest to high protection against influenza.[1][2] The United States Centers for Disease Control and Prevention (CDC) estimates that vaccination against influenza reduces sickness, medical visits, hospitalizations, and deaths.[3][4] Immunized workers who do catch the flu return to work half a day sooner on average.[5] Vaccine effectiveness in those over 65 years old remains uncertain due to a lack of high-quality research.[6][7] Vaccinating children may protect those around them.[1]

Vaccination against influenza began in the 1930s, with large-scale availability in the United States beginning in 1945.[8][9] It is on the World Health Organization's List of Essential Medicines.[10]

The vaccines are generally safe; fever occurs in five to ten percent of children vaccinated, and temporary muscle pains or feelings of tiredness may occur. In certain years, the vaccine was linked to an increase in Guillain–Barré syndrome among older people at a rate of about one case per million doses.[1] Although most influenza vaccines are produced using egg proteins, they are still recommended as safe for people who have severe egg allergies,[11] as no increased risk of allergic reaction to the egg-based vaccines has been shown for people with egg allergies.[12] Vaccines produced using other technologies, notably recombinant vaccines and those based on cell culture rather than egg protein, started to become available from 2012 in the US,[13] and later in Europe[14] and Australia.[12] Influenza vaccines are not recommended in those who have had a severe allergy to previous versions of the vaccine itself.[1][11] The vaccine comes in inactive and weakened viral forms. The live, weakened vaccine is generally not recommended in pregnant women, children less than two years old, adults older than 50, or people with a weakened immune system.[1] Depending on the type they can be injected into a muscle, sprayed into the nose, or injected into the middle layer of the skin (intradermal).[1] The intradermal vaccine was not available during the 2018–2019 and 2019–2020 influenza seasons.[15][16][17][18]

ReferencesEdit

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 World Health Organization (November 2012). "Vaccines against influenza WHO position paper". Weekly Epidemiological Record. 87 (47): 461–76. hdl:10665/241993. PMID 23210147. Lay summary (PDF).
  2. Manzoli L, Ioannidis JP, Flacco ME, De Vito C, Villari P (July 2012). "Effectiveness and harms of seasonal and pandemic influenza vaccines in children, adults and elderly: a critical review and re-analysis of 15 meta-analyses". Human Vaccines & Immunotherapeutics. 8 (7): 851–62. doi:10.4161/hv.19917. PMC 3495721. PMID 22777099.
  3. Rolfes MA, Foppa IM, Garg S, Flannery B, Brammer L, Singleton JA, et al. (December 9, 2016). "2015–2016 Estimated Influenza Illnesses, Medical visits, and Hospitalizations Averted by Vaccination in the United States". U.S. Centers for Disease Control and Prevention (CDC). Archived from the original on December 2, 2019. Retrieved December 24, 2017.   This article incorporates text from this source, which is in the public domain.
  4. Centers for Disease Control and Prevention (16 January 2020). "Benefits of Flu Vaccination During 2018-2019 Flu Season". Centers for Disease Control and Prevention (CDC). Retrieved 10 April 2020.
  5. Demicheli V, Jefferson T, Ferroni E, Rivetti A, Di Pietrantonj C (February 2018). "Vaccines for preventing influenza in healthy adults". Cochrane Database of Systematic Reviews. 2: CD001269. doi:10.1002/14651858.CD001269.pub6. PMC 6491184. PMID 29388196.
  6. Osterholm MT, Kelley NS, Sommer A, Belongia EA (January 2012). "Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis". The Lancet. Infectious Diseases. 12 (1): 36–44. doi:10.1016/S1473-3099(11)70295-X. PMID 22032844.
  7. Demicheli V, Jefferson T, Di Pietrantonj C, Ferroni E, Thorning S, Thomas RE, Rivetti A (February 2018). "Vaccines for preventing influenza in the elderly". Cochrane Database of Systematic Reviews. 2: CD004876. doi:10.1002/14651858.CD004876.pub4. PMC 6491101. PMID 29388197.
  8. Compans RW (2009). Vaccines for pandemic influenza. Dordrecht: Springer. p. 49. ISBN 978-3540921653.
  9. Vaccine Analysis: Strategies, Principles, and Control. Springer. 2014. p. 61. ISBN 978-3662450246.
  10. World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  11. 11.0 11.1 "Flu Vaccine and People with Egg Allergies". U.S. Centers for Disease Control and Prevention (CDC). November 25, 2019. Archived from the original on December 2, 2019. Retrieved December 2, 2019.   This article incorporates text from this source, which is in the public domain.
  12. 12.0 12.1 Roberts, Lauren (27 March 2021). "Australia's first cell-based influenza vaccines to roll out this flu season". ABC News. Retrieved 28 April 2021.
  13. Cite error: The named reference novartiscell was used but no text was provided for refs named (see the help page).
  14. Cite error: The named reference Supemtek EPAR was used but no text was provided for refs named (see the help page).
  15. Cite error: The named reference pmid31441906 was used but no text was provided for refs named (see the help page).
  16. "Intradermal Influenza (Flu) Vaccination". U.S. Centers for Disease Control and Prevention (CDC). October 31, 2018. Archived from the original on October 14, 2019. Retrieved October 14, 2019.   This article incorporates text from this source, which is in the public domain.
  17. "Influenza vaccines – United States, 2019–20 influenza season". U.S. Centers for Disease Control and Prevention (CDC). August 22, 2019. Archived from the original on October 14, 2019. Retrieved October 14, 2019.   This article incorporates text from this source, which is in the public domain.
  18. "Influenza Virus Vaccine Inactivated". The American Society of Health-System Pharmacists. November 19, 2018. Archived from the original on October 14, 2019. Retrieved October 13, 2019.