$34 Million Funds Sixth Avian Influenza Pandemic Preparedness Award

Donald Hackett — Mon, 07 Oct 2024 16:21:36 +0000

Reviewer:

As the United States continues reporting avian influenza cases in animals and people, the U.S. government is making another investment in pandemic prevention vaccines.

The emergence of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b viruses and their transmission to animals and humans poses a significant global public health threat.

CSL Seqirus recently announced it had been selected by the Biomedical Advanced Research and Development Authority (BARDA) to fill and finish additional pre-pandemic vaccine doses as part of the National Pre-Pandemic Influenza Vaccine Stockpile (NPIVS).

The NPIVS utilizes the HHS Influenza Risk Assessment Tool to identify and evaluate potential pandemic influenza virus threats.

Under the terms of the $34 million award, CSL Seqirus will deliver approximately three million finished doses of MF59®-adjuvanted H5N1 pre-pandemic vaccine and manufacture an additional lot of H5N8 antigen.

Recent evidence produced by the U.S. CDC indicates both the H5N1 strain and the H5N8 strain are similar to A(H5N1) strains circulating among U.S. dairy cattle. It suggests that both strains could induce protection in vaccinated people.

Avian influenza viruses do not usually infect humans; however, humans have been infected with them in rare cases.

The U.S. latest acquisition of a pre-pandemic vaccine will further supplement BARDA's stockpile of vaccines to support the U.S. government's pre-pandemic response to avian influenza.

"Although the risk to Americans from influenza A(H5) virus infection remains low, we're leaning forward with our preparedness efforts," said BARDA Director and Deputy Assistant Secretary for Preparedness and Response Gary Disbrow, Ph.D, in a press release.

CSL Seqirus' manufacturing facility utilizes a highly scalable production method. It is positioned to deliver 150 million influenza vaccine doses within six months of a pandemic declaration to support an influenza pandemic response.

"As a global leader in pandemic preparedness, this new award from BARDA emphasizes the value of collaboration in tackling global health threats as they emerge," said Marc Lacey, CSL Seqirus, Global Executive Director for Pandemic, in a press release on October 4, 2024.

"We're proud to be a pandemic partner to over thirty governments globally and to do our part to help safeguard and protect public health."

According to a Brief Communication published in July 2024 by Nature Medicine, the stockpiled US-licensed adjuvanted H5N1 vaccines generate cross-neutralizing antibodies against circulating HPAI H5N1 clade 2.3.4.4b in humans and may be helpful as bridging vaccines until updated H5N1 vaccines become available.

As of October 6, 2024, U.S. FDA-approved avian influenza vaccines, such as Audenz™, are not commercially available. Furthermore, the FDA says annual flu shots are unlikely to protect people during avian influenza (bird flu) pandemics.

Sub Title:

CSL Seqirus Audenz vaccine protect people from disease caused by the influenza A virus H5N1

References:

$34 million investment is the sixth avian influenza pandemic preparedness award made to CSL Seqirus by BARDA

Licensed H5N1 vaccines generate cross-neutralizing antibodies against highly pathogenic H5N1 clade 2.3.4.4b influenza virus

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health, vaccines, vaccinations

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Fact checked:

Tuesday, October 8, 2024 - 07:15

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Mortality Due to H5N1 Human Infections Could Decrease by Switching Receptor

Don Hackett — Tue, 30 Jul 2024 19:11:16 +0000

Reviewer:

Robert Carlson, MD

The Lancet Infectious Disease recently published a Correspondence offering insights regarding the current influenza A(H5N1) outbreak in dairy cattle and poultry, raising concerns about increased risk for sustained human-to-human transmission.

On July 24, 2024, these researchers wrote that avian influenza viruses' increasing host range and ability to spread between mammals and humans raise concerns about a potential pandemic risk. This pandemic risk is a concern as mortality was 52% of the 876 influenza A(H5N1) cases reported in Europe since 2002.

Our experience from the 2009 H1N1 pandemic was that admissions to intensive care were due to H1N1 pneumonia.

They argue that the high mortality might be due to an H5N1 virus pneumonia, and should the H5N1 switch to the upper airway receptor for human influenza (H1, H2, and H3), α2,6-sialic acid (SA α2,6), we hypothesize that the mortality would be lower because most infections would be restricted to the upper respiratory tract infections and only in rare cases pneumonia.

The influenza virus hemagglutinin protein binds to sialic acid receptors on the host cells, which can be either SA α2,3 or SA α2,6. SA α2,3 is found on specific human tissues, especially lung alveoli, and conjunctiva, while SA α2,6 is predominantly found in the upper respiratory tract of humans.

The avian influenza virus uses the SA α2,3 receptor, whereas the three human influenza viruses (H1N1, H2N2, and H3N2) use the SA α2,6 receptor.

These researchers say Avian influenza can occasionally cross the species barrier from animals to humans. This transmission likely requires exposure to a high number of avian influenza viruses for the virus to reach the SA α2,3 receptor in the alveoli, after which the infected person will develop diffuse, double-sided pneumonia.

Receptor distribution also explains why conjunctivitis has been reported in at least three of the five reported human H5N1 cases infected from cattle in the USA.

Therefore, we hypothesize that if the H5N1 virus switched receptor preference from SA α2,3 to the human upper respiratory receptor SA α2,6, the virus might cause a less severe upper respiratory infection, and the mortality rate would decrease because most cases would no longer be due to influenza virus pneumonia.

Even if mortality were lower due to receptor switching, widespread transmission could still lead to a substantial healthcare burden and morbidity and mortality due to potentially high numbers of concurrent cases.

These researchers were supported by a Danish National Research Foundation grant and declared no competing interests.

The complete, unedited article is posted at this link.

As of July 30, 2024, various governments have invested in producing avian influenza vaccines, which would become available during a bird flu or cow flu pandemic.

Sub Title:

Avian influenza mortality might be due to a H5N1 virus pneumonia

Reference:

Mortality of H5N1 human infections might be due to H5N1 virus pneumonia and could decrease by switching receptor

Image:

Google News Keywords:

Bird flu, vaccinations

Featured:

Fact checked:

Wednesday, July 31, 2024 - 06:00

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by Matthias Böckel

Audenz Avian Influenza Vaccine

$34 Million Funds Sixth Avian Influenza Pandemic Preparedness Award

Mortality Due to H5N1 Human Infections Could Decrease by Switching Receptor