H5N1 vaccine

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H5N1 vaccine
Vaccine description
TargetH5N1
Vaccine type Inactivated
Clinical data
Trade names Audenz, Aflunov
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A H5N1 vaccine is an influenza vaccine intended to provide immunization to influenza A virus subtype H5N1.

Contents

Vaccination of poultry against the avian H5N1 influenza epizootic is widespread in certain countries. [6] [7] Some vaccines also exist for use in humans, and others are in testing. As of July 2024 these include Aflunov, Celldemic and Seqirus/Audenz. [8] [9]

The hemagglutinin protein is the main viral antigen of influenza A viruses, including the H5N1 subtype. Vaccination can induce antibodies that block the functions of the H5 hemagglutinin and neutralize virus infectivity. [10]

The influenza virus is highly variable - the H5N1 virus now infecting cattle in the USA [a] is different from the H5N1 viruses that first showed up in poultry in 1997 and subsequently spread through wild bird populations in all continents except Australia. Scott Hensley, Professor of Microbiology at Perelman School of Medicine, has stated “If this H5 causes a pandemic, it likely is not going to be identical to whatever is circulating in cows [currently].” This means that any vaccine developed in anticipation of a human pandemic is unlikely to be an exact match to the pandemic strain. [11] However licensed vaccines can be updated in a process similar to that used for updating seasonal influenza vaccines. [12]

Timeline

In December 2024 the UK government announced the purchase of five million doses of human H5 influenza vaccine to boost the country’s resilience in the event of a possible H5 influenza pandemic. The vaccine will be manufactured by CSL Seqirus UK Limited. [13] The vaccine is based on the A/H5N8/Astrakhan/3212/2020 clade 2.3.4.4b strain of influenza. [14] If needed, the H5 vaccine could be used while a pandemic-specific vaccine is developed and produced. [15]

In June 2024, the European Commission signed a four-year contract with CSL Seqirus to secure 665,000 pre-pandemic vaccines with a provision for a further 40 million doses of avian flu vaccines for 15 member states. [16]

In May 2024, CSL Seqirus was selected by the US government to supply 4.8 million doses of an H5 vaccine to the National Pre-Pandemic Influenza Vaccine Stockpile program. The vaccine is well matched to the H5N1 strains currently circulating in wild birds and cattle. [17]

In January 2020, the U.S. Food and Drug Administration (FDA) approved Audenz, an adjuvanted influenza A (H5N1) monovalent vaccine. [2] [18] Audenz is a vaccine indicated for active immunization for the prevention of disease caused by the influenza strain which is contained in the vaccine (currently A/turkey/Turkey/1/2005 NIBRG-23). [19] In the event of an outbreak of the disease in humans, the strain could be updated in a process similar to that used for updating seasonal vaccines. [2] [12]

In November 2013, the U.S. Food and Drug Administration (FDA) approved an experimental H5N1 bird flu vaccine to be held in stockpiles. [20] [21] In a clinical trial including 3,400 adults, 91% of people age 18–64 and 74% of people age 65 or older formed an immune response sufficient to provide protection. Reported adverse effects were generally mild, with pain at the injection site being the most common adverse effect. [22]

Some older, egg-based H5N1 vaccines for humans that have been licensed are:

Other licensed H5N1 vaccines include:

Vaccine Production

H5N1 continually mutates, meaning vaccines based on current samples of avian H5N1 cannot be depended upon to work in the case of a future pandemic of H5N1. While there can be some cross-protection against related flu strains, the best protection would be from a vaccine specifically produced for any future pandemic flu virus strain. Daniel R. Lucey, co-director of the Biohazardous Threats and Emerging Diseases graduate program at Georgetown University, has made this point, "There is no H5N1 pandemic so there can be no pandemic vaccine." [30] However, "pre-pandemic vaccines" have been created; are being refined and tested; and do have some promise both in furthering research and preparedness for the next pandemic. [31] Vaccine manufacturing companies are being funded to increase flexible capacity so that if a pandemic vaccine is needed, facilities will be available for rapid production of large amounts of a vaccine specific to a new pandemic strain. [32]

Notes

  1. ↑ As of December 2024

Related Research Articles

<i>Influenza A virus</i> Species of virus

Influenza A virus (IAV) is the only species of the genus Alphainfluenzavirus of the virus family Orthomyxoviridae. It is a pathogen with strains that infect birds and some mammals, as well as causing seasonal flu in humans. Mammals in which different strains of IAV circulate with sustained transmission are bats, pigs, horses and dogs; other mammals can occasionally become infected.

<span class="mw-page-title-main">Avian influenza</span> Influenza caused by viruses adapted to birds

Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A virus, which is enzootic in many bird populations.

<span class="mw-page-title-main">Influenza A virus subtype H5N1</span> Subtype of influenza A virus

Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations, and also panzootic. A/H5N1 virus can also infect mammals that have been exposed to infected birds; in these cases, symptoms are frequently severe or fatal.

<span class="mw-page-title-main">Influenza vaccine</span> Vaccine against influenza

Influenza vaccines, colloquially known as flu shots or the flu jab, are vaccines that protect against infection by influenza viruses. New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes. While their effectiveness varies from year to year, most provide modest to high protection against influenza. Vaccination against influenza began in the 1930s, with large-scale availability in the United States beginning in 1945.

<span class="mw-page-title-main">Live attenuated influenza vaccine</span> Nasal influenza vaccine

Live attenuated influenza vaccine (LAIV) is a type of influenza vaccine in the form of a nasal spray that is recommended for the prevention of influenza.

<span class="mw-page-title-main">Influenza pandemic</span> Pandemic involving influenza

An influenza pandemic is an epidemic of an influenza virus that spreads across a large region and infects a large proportion of the population. There have been five major influenza pandemics in the last 140 years, with the 1918 flu pandemic being the most severe; this is estimated to have been responsible for the deaths of 50–100 million people. The 2009 swine flu pandemic resulted in under 300,000 deaths and is considered relatively mild. These pandemics occur irregularly.

Singapore has taken a series of measures against avian influenza and the potential threat of a pandemic.

<span class="mw-page-title-main">Transmission and infection of H5N1</span> Spread of an influenza virus

Transmission and infection of H5N1 from infected avian sources to humans has been a concern since the first documented case of human infection in 1997, due to the global spread of H5N1 that constitutes a pandemic threat.

<span class="mw-page-title-main">H5N1 genetic structure</span> Genetic structure of Influenza A virus

The genetic structure of H5N1, a highly pathogenic avian influenza virus, is characterized by a segmented RNA genome consisting of eight gene segments that encode for various viral proteins essential for replication, host adaptation, and immune evasion.

<span class="mw-page-title-main">H5N1 vaccine clinical trials</span> Clinical trials of influenza vaccine

H5N1 clinical trials are clinical trials concerning H5N1 vaccines, which are intended to provide immunization to influenza A virus subtype H5N1. They are intended to discover pharmacological effects and identify any adverse reactions the vaccines may achieve in humans.

<span class="mw-page-title-main">Fujian flu</span> Strains of influenza

Fujian flu refers to flu caused by either a Fujian human flu strain of the H3N2 subtype of the Influenza A virus or a Fujian bird flu strain of the H5N1 subtype of the Influenza A virus. These strains are named after Fujian, a coastal province in Southeast China.

<span class="mw-page-title-main">Human mortality from H5N1</span>

H5N1 influenza virus is a type of influenza A virus which mostly infects birds. H5N1 flu is a concern due to the fact that its global spread that may constitute a pandemic threat. The yardstick for human mortality from H5N1 is the case-fatality rate (CFR); the ratio of the number of confirmed human deaths resulting from infection of H5N1 to the number of those confirmed cases of infection with the virus. For example, if there are 100 confirmed cases of a disease and 50 die as a consequence, then the CFR is 50%. The case fatality rate does not take into account cases of a disease which are unconfirmed or undiagnosed, perhaps because symptoms were mild and unremarkable or because of a lack of diagnostic facilities. The Infection Fatality Rate (IFR) is adjusted to allow for undiagnosed cases.

<span class="mw-page-title-main">Pandemrix</span> Flu vaccine

Pandemrix is an influenza vaccine for influenza pandemics, such as the 2009 flu pandemic. The vaccine was developed by GlaxoSmithKline (GSK) and patented in September 2006.

<span class="mw-page-title-main">Influenza</span> Infectious disease

Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin one to four days after exposure to the virus and last for about two to eight days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia from the virus or a subsequent bacterial infection. Other complications include acute respiratory distress syndrome, meningitis, encephalitis, and worsening of pre-existing health problems such as asthma and cardiovascular disease.

<span class="mw-page-title-main">2009 swine flu pandemic vaccine</span> Protection against the H1N1/09 virus

The 2009 swine flu pandemic vaccines were influenza vaccines developed to protect against the pandemic H1N1/09 virus. These vaccines either contained inactivated (killed) influenza virus, or weakened live virus that could not cause influenza. The killed virus was injected, while the live virus was given as a nasal spray. Both these types of vaccine were produced by growing the virus in chicken eggs. Around three billion doses were produced, with delivery in November 2009.

<span class="mw-page-title-main">Influenza A virus subtype H7N9</span> Subtype of the influenza A virus

Influenza A virus subtype H7N9 (A/H7N9) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations. The virus can spread rapidly through poultry flocks and among wild birds; it can also infect humans that have been exposed to infected birds.

Cell-based vaccines are developed from mammalian or more rarely avian or insect cell lines rather than the more common method which uses the cells in embryonic chicken eggs to develop the antigens. The potential use of cell culture techniques in developing viral vaccines has been widely investigated in the 2000s as a complementary and alternative platform to the current egg-based strategies.

Type A influenza vaccine is for the prevention of infection of influenza A virus and also the influenza-related complications. Different monovalent type A influenza vaccines have been developed for different subtypes of influenza A virus including H1N1 and H5N1. Both intramuscular injection or intranasal spray are available on market. Unlike the seasonal influenza vaccines which are used annually, they are usually used during the outbreak of certain strand of subtypes of influenza A. Common adverse effects includes injection site reaction and local tenderness. Incidences of headache and myalgia were also reported with H1N1 whereas cases of fever has also been demonstrated with H5N1 vaccines. It is stated that immunosuppressant therapies would reduce the therapeutic effects of vaccines and that people with egg allergy should go for the egg-free preparations.

An H5N8 vaccine is an influenza vaccine intended to provide acquired immunity against H5 subtype influenza A viruses. It is given via Intramuscular injection.

References

  1. ↑ "Health product highlights 2021: Annexes of products approved in 2021". Health Canada . 3 August 2022. Retrieved 25 March 2024.
  2. 1 2 3 "Audenz". U.S. Food and Drug Administration (FDA). 31 January 2020. STN: 125692. Retrieved 5 February 2020.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  3. ↑ "Influenza A (H5N1) Virus Monovalent Vaccine, Adjuvanted". U.S. Food and Drug Administration. 14 November 2019. Retrieved 21 September 2024.
  4. ↑ "Influenza A (H5N1) Virus Monovalent Vaccine, Adjuvanted, manufactured". U.S. Food and Drug Administration. 22 November 2013. Retrieved 21 September 2024.
  5. ↑ "Aflunov EPAR". European Medicines Agency (EMA). 29 November 2010. Retrieved 21 September 2024.
  6. ↑ "Bird flu vaccination policies by country". Reuters. 17 February 2023. Retrieved 30 July 2024.
  7. ↑ "Vaccination of poultry against highly pathogenic avian influenza – Available vaccines and vaccination strategies". efsa.europa.eu. 10 October 2023. Retrieved 9 May 2024.
  8. ↑ "Vaccines for pandemic influenza". European Medicines Agency. Retrieved 30 July 2024.
  9. ↑ "Audenz". U.S. Food and Drug Administration (FDA). 31 January 2020. STN: 125692. Archived from the original on 6 August 2020. Retrieved 5 February 2020.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  10. ↑ Xiong X, Corti D, Liu J, Pinna D, Foglierini M, Calder LJ, et al. (July 2015). "Structures of complexes formed by H5 influenza hemagglutinin with a potent broadly neutralizing human monoclonal antibody". Proceedings of the National Academy of Sciences of the United States of America. 112 (30): 9430–9435. Bibcode:2015PNAS..112.9430X. doi: 10.1073/pnas.1510816112 . PMC   4522749 . PMID   26170284.{{cite journal}}: CS1 maint: overridden setting (link)
  11. ↑ Fox M. "We May Not Have Enough Bird Flu Vaccines when We Need Them". Scientific American. Retrieved 12 December 2024.
  12. 1 2 "FDA Briefing Document - Vaccines and Related Biological Products Advisory Committee Meeting". Food and Drug Administration . 10 October 2024. Retrieved 12 December 2024.
  13. ↑ "UK secures H5 influenza vaccine to boost pandemic preparedness". GOV.UK. Retrieved 12 December 2024.
  14. ↑ "CSL Seqirus Announces New Pandemic Preparedness Award from the UK Government". www.cslseqirus.co.uk. Retrieved 12 December 2024.
  15. ↑ "UK orders H5 avian flu vaccine for pandemic preparedness | CIDRAP". www.cidrap.umn.edu. 3 December 2024. Retrieved 12 December 2024.
  16. ↑ "Commission secures access for Member States to 665,000 doses of zoonotic influenza vaccines to prevent avian flu". European Commission. 11 June 2024.
  17. ↑ "CSL Seqirus Announces US Government Award in Response to Avian Influenza". CSL Seqirus. 30 May 2024. Retrieved 13 December 2024.
  18. ↑ Keown A (4 February 2020). "FDA Approves Seqirus' Audenz as Vaccine Against Potential Flu Pandemic". BioSpace. Retrieved 5 February 2020.
  19. ↑ "Package Insert - AUDENZ". US Food and Drug Administration. October 2023. Retrieved 12 December 2024.
  20. ↑ "Influenza A (H5N1) Virus Monovalent Vaccine, Adjuvanted, manufactured". U.S. Food and Drug Administration (FDA). 22 November 2013. Retrieved 5 February 2020.
  21. ↑ "Influenza A (H5N1) Virus Monovalent Vaccine, Adjuvanted". U.S. Food and Drug Administration (FDA). 23 April 2019. STN#: 125419. Retrieved 5 February 2020.
  22. ↑ Lowes R (22 November 2013). "FDA Approves First Adjuvanted Vaccine for H5N1 Bird Flu". Medscape. Retrieved 16 March 2015.
  23. ↑ "H5N1 Influenza Virus Vaccine Questions and Answers". U.S. Food and Drug Administration (FDA). 17 April 2007. Retrieved 5 February 2020.
  24. ↑ "Diagnostic Targets and Potential Vaccine Against H5n1 Avian Influenza". U.S. Food and Drug Administration (FDA). 11 September 2019. Retrieved 5 February 2020.
  25. ↑ "EU licenses first pre-pandemic bird flu vaccine LONDON". Reuters. 19 May 2008.
  26. 1 2 "Adjupanrix EPAR". European Medicines Agency (EMA). 17 September 2018. Retrieved 13 January 2021.
  27. 1 2 "Foclivia EPAR". European Medicines Agency . 17 September 2018. Retrieved 13 January 2021.
  28. 1 2 "Aflunov EPAR". European Medicines Agency (EMA). 17 September 2018. Retrieved 13 January 2021.
  29. ↑ "Pumarix EPAR". European Medicines Agency (EMA). 17 September 2018. Retrieved 13 January 2021.
  30. ↑ "H5N1 Influenza Pandemic Threat (Avian Flu) | Sino Biological". www.sinobiological.com. Archived from the original on 12 September 2024. Retrieved 13 December 2024.
  31. ↑ "Vaccines for pandemic influenza | European Medicines Agency (EMA)". www.ema.europa.eu. Retrieved 13 December 2024.
  32. ↑ McElwee F, Newall A (July 2024). "The Value of Flexible Vaccine Manufacturing Capacity: Value Drivers, Estimation Methods, and Approaches to Value Recognition in Health Technology Assessment". PharmacoEconomics. 42 (Suppl 2): 187–197. doi:10.1007/s40273-024-01396-6. PMC   11230966 . PMID   38819720.

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