US poised to invest millions in mRNA bird flu vaccine amid H5N1 scare

Test tubes labelled "Bird Flu" and a piece of paper in the colours of the U.S. national flag are seen in this picture illustration
The US is understood to be nearing an agreement with Moderna to finance human trials for its experimental mRNA bird flu vaccine - Dado Ruvic/REUTERS

The US government is poised to announce a multimillion-dollar investment in mRNA vaccines for H5N1 bird flu. The move comes as the virus continues to spread in mammals, threatening a new pandemic if it makes the jump to humans.

The US Biomedical Advanced Research and Development Authority (BARDA) is understood to be nearing an agreement with Moderna to finance human trials for its experimental mRNA bird flu vaccine. The deal would include a commitment to stockpile millions of vaccines if the trials were successful, the Financial Times reported on Thursday.

Senior officials at the World Health Organization (WHO) in Geneva welcomed the news, amid fears the H5N1 outbreak, which has killed millions of animals in the last two years, could yet spread to humans.

Jeremy Farrar, chief scientist at the WHO, said investing in mRNA jabs for H5N1 was “an important step forward”, while Maria Van Kerkhove, head of the emerging diseases and zoonosis unit, said it demonstrated “active pandemic preparedness” on the part of the Americans. The recent progress of H5N1 into US cattle was “concerning,” she added.

H5N1, which has a human case fatality rate of 50 per cent, has been circulating for more than 20 years, causing thousands of human infections and more than 400 deaths primarily in people working with animals over that period.

Dairy cattle feed at a farm in New Mexico
The H5N1 strain of avian influenza has infected cattle at a number of dairy farms in the US - Rodrigo Abd/AP

In the last few years, it has surged again globally, infecting millions of wild and domesticated birds as well as mammals ranging from foxes and mink to penguins and seals.

The infection of cattle across the US has experts worried that the virus could yet mutate to spread efficiently in humans, causing another pandemic. At least two US farm workers have become infected with mild disease and more are expected to be found as testing on US farms becomes more widespread.

According to an unnamed source involved in the discussions, tens of millions of dollars of funding from BARDA could be made available to Moderna as soon as next month.

The move comes as health ministers from across the world are gathered at the World Health Assembly in Geneva to consider how to improve pandemic preparedness.

One of the major advantages of mRNA vaccines, as demonstrated during the Covid-19 pandemic, is their potential for rapid and relatively straightforward production.

Currently, over 80 per cent of the world’s influenza vaccines are grown inside chicken eggs, a process that can take up to six months and is especially difficult with the H5N1 influenza strain.

Jabs in the US’s pandemic portfolio from GSK, Sanofi, and CSL Seqirus all provide immunity to H5N1, but rely on this time-intensive method – meaning that if H5N1 begins to spread among humans, they may not be ready in time to fully combat the first wave of a pandemic.

Eggs may also run short as chicken flocks contract the virus and are culled.

In past influenza pandemics, including the Swine Flu outbreak in 2009, vaccines were often delayed until after the initial waves had already subsided.

Prof Paul Kelly, chief medical officer of Australia, welcomed the news, saying it was important to “learn the lessons of the Covid pandemic”, think ahead on vaccine production, and ensure that “not all eggs were in the same basket”.

An early investment by BARDA in mRNA vaccines for H5N1 would be “appropriate and wise”, he added.

The US government is also said to be in talks with Pfizer over supporting the development of its mRNA vaccine in targeting H5N1, but no agreement has yet been reached.

Dr Rick Bright, an immunologist and influenza expert, said the US government should consider more options, casting its net wide.

“While it a good to see BARDA considering partnerships with Moderna and Pfizer, it’s also important that they look at additional companies and technologies that could be helpful in pandemic response and even seasonal influenza vaccine impact,” he said.

“For example, GSK and Curevac recently launched an H5N1 vaccine clinical trial and there are other companies that are developing influenza vaccines that can be delivered in the form of an oral capsule or skin patch,” Dr Bright added.

Bird flu has so far been detected in poultry farms across the world, including the UK.  In the US, over 68 herds of dairy cattle across nine states have also become infected.

So far this year, two dairy workers – one in Texas, one in Michigan – have tested positive for the virus. In the most recent case, the virus demonstrated a mutation that evidenced it has better adapted to spread between humans.

The WHO still considers the risk to humans low but urged countries to rapidly share information to enable real-time monitoring of the situation to ensure preparedness as the virus continues to spread.

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