Scientists are racing to develop a new bird flu vaccine

I became a 13-year-old girl in Canada Very sick with H5N1or bird flu, in late 2024, forcing her to be placed on a ventilator. Around the same time, an elderly person in Louisiana was diagnosed with the first “serious” case in the United States

As bird flu continues to increase, many are asking what tools we should use to fight it – vaccines in particular – if such intervention becomes necessary.

“Public health and infectious disease professionals around the world are monitoring bird flu very carefully,” says Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center and spokesman for the Infectious Diseases Society of America. “The concern is that this virus could gain the ability to attach to human cells and spread widely. This would certainly open the door to a new pandemic.”

For this to happen, the H5N1 virus must develop the right mutations that allow it to infect human cells more easily — a process that could happen more easily if someone were infected with seasonal influenza and the H5N1 virus, for example, allowing the virus to replicate. Two viruses exchange genetic information and recombine into a strain that infects humans and spreads easily.

Fortunately, that has not happened yet, but health officials are not waiting. A vaccine is being worked on to protect the public in the event of a pandemic, and earlier this year, Dr. Mandy Cohen, director of the US Centers for Disease Control and Prevention (CDC), pointed to mRNA as a preferred platform for the shootout where vaccines could be developed and distributed quickly.

Here are the latest efforts to develop a new bird flu vaccine.

Is there really an H5N1 vaccine??

Several vaccines target the H5N1 virus, and the national stockpile contains doses of all of them. These vaccines target variants of the H5N1 virus that were circulating when the vaccines were developed years ago, but health experts expect they will still provide some protection against serious disease.

“Fortunately, current vaccine candidates neutralize strains circulating in the laboratory,” health officials from the US National Institute of Allergy and Infectious Diseases wrote on December 31. Editorial in New England Journal of Medicine. A small number of healthy volunteers have been vaccinated with these H5N1 vaccines, and the antibodies they create appear to neutralize the circulating virus in laboratory tests. But these vaccines have not yet been tested in clinical trials, as there have not been enough cases of H5N1 infection in humans to compare vaccinated people to unvaccinated people.

What about an mRNA vaccine for H5N1?

There’s no vaccine yet, but several companies — including Moderna, Pfizer, and GlaxoSmithKline (in collaboration with CureVac) — are working on such a shot. In July, the US government’s Biomedical Advanced Research and Development Authority (BARDA) announced. Moderna awarded $176 million To develop an updated mRNA H5N1 vaccine. All mRNA vaccine candidates are in the early stages of testing in humans for safety and efficacy.

The shots are based on the same mRNA technology that has been used to create COVID-19 vaccines. In recent weeks, scientists led a team from the CDC I mentioned The mRNA-based H5N1 vaccine helped ferrets generate strong antibody responses against the virus and survive the lethal dose that killed ferrets that did not receive the vaccine.

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Dr. Drew Weissman, director of vaccine research at the University of Pennsylvania and a 2023 Nobel Prize winner for his work on pioneering mRNA technology in vaccines, and colleagues also reported encouraging results with a vaccine they developed and tested in ferrets. The shot, which targets the H5N1 strain that has caused recent infections in chickens and livestock, prevented serious illness and death from H5N1 in rodents. Unvaccinated animals did not survive.

“The real advantage of mRNA vaccines in the context of a pandemic is the ability to update vaccines as needed,” says Scott Hensley, a professor of microbiology at the University of Pennsylvania School of Medicine, who worked with Weissman to develop the vaccine. “The beauty of mRNA is the ability to change the vaccine in a single moment.”

When can an updated vaccine be available?

While developing an mRNA vaccine may only take a few months, testing the vaccine in clinical trials will take much longer. “We know the vaccines will be well-tolerated and safe because they have been in the context of COVID-19,” Hensley says. “But any new antigen needs to be tested.”

In order to avoid delays in making vaccines available to the public in the event of a pandemic, governments must invest in conducting large-scale, late-stage clinical testing before the outbreak, Hensley says. “It would be an investment in something that you’re not sure will cause a pandemic,” he says. “But this is a decision that governments have to make. In my opinion, it would be a good idea to spend money when dealing with a virus that has the potential of this particular virus.

Another way to avoid this delay and reduce the number of people who become ill with bird flu at an epidemic level is to develop and more widely distribute a targeted vaccine. Influenza comes in four main subtypes – A, B, C and D – and types A and B cause most infections in humans. (H5N1 is type A.) Hensley developed a vaccine candidate that could recognize all 20 types of influenza A and B — including H5N1 — and found that it generated strong immune responses in mice and ferrets. In addition, when vaccinated ferrets were exposed to slightly different flu variants within those subtypes, they still produced good immune responses against them.

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While the vaccine did not protect the animals from infection, they did not get as sick. “What it does is prime the immune system to respond and eliminate the virus more quickly,” Hensley says. “So the idea is to provide the population with the kind of vaccine that would limit the initial severe illness and death in a pandemic. This would buy some time for more specifically matched vaccines that could be developed and used as boosters. Schools would not have to “Closing their doors, people may still get infected but not die.”

The National Institutes of Health is sponsoring trials of this vaccine, which could change the way we vaccinate against influenza and other emerging threats. If such broad-spectrum vaccinations prove safe and effective, they would be best given to young children so their immune systems can be trained to recognize a wide range of flu types early on, Hensley says. This would prime them for faster and more effective immune responses to vaccines and infections as they get older.

Who should be vaccinated against H5N1?

Because the CDC says that The risk of bird flu remains low For the general public, there are no recommendations for anyone in the United States to get vaccinated against H5N1 at this time. Some experts believe that dairy workers and others who have close contact with potentially infected animals, such as poultry and livestock, She should be vaccinated To protect them from infection, but American health officials have not yet made this decision, indicating that a full understanding of the risks of the H5N1 virus to people and the benefits of the vaccine Not entirely clear.

Finland has offered people most at risk of bird flu – including fur industry workers who handle wild pigs and workers in the poultry industry – bird flu. Serum It’s made by Seqirus, which uses a more traditional vaccine technology that involves an inactivated form of the virus.