Avian Influenza Vaccines

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Last reviewed
April 19, 2024
Content Overview
Avian influenza and Pandemic Bird Flu vaccines are U.S. FDA approved.

Avian Influenza (Bird Flu) Vaccines 2024

The U.S. National Influenza Vaccine Modernization Strategy and the American Pandemic Preparedness Plan outlined the United States (U.S.) priorities in avian influenza (Bird Flu) vaccines. According to the U.S. Centers for Disease Control and Prevention (CDC), about 20 million H5N1 and 12 million H7N9 vaccines were available in the National Strategic Stockpile as of June 2023. The CDC also confirmed in October 2023 that an H5 candidate vaccine virus (CVV) similar to the hemagglutinin (H.A.) protein of H5N1 clade A(H5) Candidate Vaccine Virus Development (pg. 37). The CDC says this H5 CVV could be used to produce a highly pathogenic avian influenza (HPAI) A(H5N1) virus vaccine for people. On September 15, 2009, four influenza vaccine manufacturers received approval from the FDA to use the influenza A (H1N1) 2009 monovalent influenza vaccine to prevent outbreaks caused by the 2009 pandemic influenza A (H1N1) virus.

On April 1, 2024, the U.S. FDA's Dr. Peter Marks informed the media that the U.S. stockpile of avian flu-specific vaccines would work well if deployed. As of April 19, 2024, U.S. FDA-approved avian influenza vaccines are not commercially available in the U.S. The FDA says annual flu shots are unlikely to protect people during avian influenza (bird flu) pandemic outbreaks.

U.S. FDA-Approved Avian Influenza Vaccines

The U.S. Food and Drug Administration (FDA) authorized CSL Seqirus Inc. Audenz™ (Influenza A(H5N1) Monovalent Vaccine, Adjuvanted) cell-based vaccine on January 31, 2020. Audenz is manufactured by I.D. Biomedical Corporation, a Canadian subsidiary of GlaxoSmithKline Biologicals.

On November 14, 2013, the FDA licensed the ID Biomedical Corporation Influenza A (H5N1) Virus Monovalent Vaccine, Adjuvante (STN#: 125419) to prevent H5N1 influenza disease. The vaccine was not commercially available. The U.S. federal government purchased it for the National Stockpile for as-needed distribution. Sanofi Pasteur's Influenza Virus Vaccine, H5N1, was FDA-approved in 2007.

CSL Seqirus BARDA Influenza Pandemic Vaccine Agreements

CSL Seqirus has been working with the U.S. Biomedical Advanced Research and Development Authority (BARDA) to support U.S. pandemic preparedness objectives. CSL Seqirus announced on August 28, 2023, that BARDA selected the company to deliver one bulk lot of H5N8 A/Astrakhan antigen to support the U.S. government's pandemic response readiness under contract number 75A50122D00004 ($46.3 million). Seqirus received an award from BARDA to produce an H5N8 A/Astrakhan virus vaccine seed, and the subsequent October 2022 announcement of the selection of CSL Seqirus to deliver an H5N8 A/Astrakhan virus vaccine candidate for assessment in a Phase 2 clinical study. Under the $30.1 million agreement, BARDA is partnering with GSK and CSL Seqirus to manufacture investigational lots of H5N8 vaccines and clinically assess the safety, immunogenicity, and dose-sparing ability of adjuvants in combination with the manufactured vaccine candidates. CSL Seqirus has established and maintains the required pandemic readiness to deliver 150 million doses of cell-based pandemic influenza vaccine within six months of an influenza pandemic declaration in the U.S. In 2022, Sequirus's Holly Springs facility successfully achieved BARDA's criteria to establish domestic manufacturing capability for innovative cell-based seasonal and pandemic influenza vaccines. 

On October 5, 2022, CSL announced results from the preclinical studies of the company's self-amplifying messenger RNA (sa-mRNA) influenza vaccine candidates. The data, published in Molecular Therapy – Methods and Clinical Development, indicate that the sa-mRNA influenza vaccine candidates produced a potent, cross-reactive immune response against pandemic and seasonal influenza strains, A(H5N1) and A(H1N1) (Swine flu). Roberta Duncan, CSL's mRNA Program Lead, commented in an article in March 2024, "The innovation of sa-mRNA brings the opportunity to provide greater public health protection against respiratory viruses and in other disease states." 

BARDA Awarded Vir Biotechnology

On October 4, 2022, the BARDA awarded California-based Vir Biotechnology, Inc. a multi-year contract with a potential value of up to $1 billion to advance the development of a complete portfolio of innovative solutions (vaccines) to address influenza and other infectious disease threats. BARDA will initially invest approximately $55 million for the ongoing and rapid development of VIR-2482, an investigational prophylactic monoclonal antibody (mAb) designed to protect against seasonal and pandemic influenza. On July 20, 2023, Vir announced that the Phase 2 PENINSULA trial evaluating VIR-2482 for preventing symptomatic influenza A illness did not meet primary or secondary efficacy endpoints.

European Recommended Avian Influenza Vaccines

According to the European Medicines Agency (EMA), one vaccine (Aflunov) is authorized for use in the European Union (EU) during avian influenza outbreaks without a declared pandemic. Aflunov contains a flu strain called A/turkey/Turkey/1/2005 (H5N1)-like strain (NIBRG-23) (clade 2.2.1). Additionally, the EMA says four pandemic-preparedness influenza vaccines authorized in the EU can be rapidly modified to protect people in a pandemic situation. The EMA's human medicines committee recommended at its February 2024 meeting Celldemic (zoonotic influenza vaccine (H5N1)(surface antigen, inactivated, adjuvanted, prepared in cell cultures)). This vaccine is intended for immunization during outbreaks of influenza coming from animals, including when public health authorities anticipate a possible pandemic. Incellipan (pandemic influenza vaccine (H5N1) (surface antigen, inactivated, adjuvanted, prepared in cell cultures)) is a pandemic preparedness vaccine intended for use only if a flu pandemic has been officially declared.

The European Commission (EC) signed a framework contract on July 28, 2022, for the joint procurement of GSK's Adjupanrix, a pandemic influenza vaccine. As a result, EC Member States can purchase up to 85 million vaccine doses, if necessary, during an influenza pandemic.

Japan Avian Influenza Vaccines

Japan Health Ministry announced in May 2023 that it is changing its avian influenza vaccine stockpile from H7N9 to the H5N1 virus. On May 25, 2023, local media reported that Japan intends to stockpile 10 million vaccines for people. In 2018, Japan began culling infected chickens. In 2008, Japan started testing bird flu vaccine versions. And in 2003, after 79 years, a HAPI virus was detected in the dead chickens.

United Kingdom Influenza Pandemic Vaccines

The U.K. Health Security Agency announced on September 26, 2023, an advance purchase agreement with CSL Seqirus to produce over 100 million influenza pandemic vaccines if or when they are needed.

Avian Influenza Monoclonal Antibody

Vir Biotechnology, Inc. VIR-2482 is an intramuscularly administered investigational prophylactic monoclonal antibody that has demonstrated in vitro the ability to neutralize significant strains of influenza A that have arisen since the 1918 Spanish flu pandemic.

Avian Influenza Vaccine Adjuvant

According to Vanderbilt University Medical Center research published in The Journal of Infectious Diseases (January 2024), avian (bird) influenza vaccines created a more robust immune response in a phase 1 study when paired with the adjuvant AS03 adjuvant manufactured by GSK.

Avian Influenza Vaccines for Birds

The United States Department of Agriculture's Agricultural Research Service (APHIS) researchers confirmed on April 14, 2023, that they are currently testing several vaccine candidates for use with birds. On May 16, 2023, APHIS approved the emergency use of an HPAI vaccine to prevent additional deaths of California Condors. The authorized vaccine is a killed, inactivated product conditionally licensed by APHIS' Center for Veterinary Biologics in 2016.   

The DIVA strategy uses an inactivated oil emulsion vaccine containing the same haemagglutinin (H) subtype as the challenge virus but a different neuraminidase (N). The possibility of using the heterologous N subtype to differentiate between vaccinated and naturally infected birds was investigated by developing an "ad hoc" serological test to detect specific anti-N1 antibodies.

The World Organisation for Animal Health (WOAH) announced on June 7, 2023, it issued a comprehensive report - Animal Health Forum on Avian Influenza – Policy to Action: The Case of Avian Influenza – Reflections for Change. It was recognized that a successful vaccination strategy must rely on authorized (bird flu) vaccines. "Vaccinating is not the end; it is just the beginning. Vaccination application needs to be managed along the supply chain, including a surveillance program to detect active infection in vaccinated animals," said Dr. David Swayne, Disease Expert and Forum rapporteur.

Influenza Pandemic Vaccine News

April 3, 2024 - Texas Biomedical Research Institute researchers are studying potential vaccines, antivirals, and antibodies against HAPI, including H5N1 strains.

April 2, 2024 - Longhorn Vaccines and Diagnostics presents a mouse study examining LHNVD-110, a novel, unconjugated single peptide vaccine comprising multiple epitopes to broadly target human and influenza viruses. Results from the poster show that LHNVD-110 generated broadly reactive antibodies to human and highly pathogenic avian influenza viruses while neutralizing seasonal and pandemic influenza strains. Peptide-based vaccines with broad strain coverage may offer useful strategies for preventing influenza, no matter the strain.

January 4, 2024 - Sanofi Pasteur manufactured an investigational subvirion inactivated monovalent vaccine from the A/Indonesia/05/2005 (H5N1) PR8-IBCDC-RG2 influenza virus, clade 2.1.3. Results from a phase 1 clinical trial sponsored by the National Institute of Allergy and Infectious Diseases published in January 2024 indicate that tryptophan, tyrosine, and nicotinate metabolism are upregulated among IIV plus GSK's AS03 adjuvant recipients compared with IIV alone. Metabolites within these pathways may serve as measures of immunogenicity and may provide mechanistic insights for adjuvanted vaccines.