Drug makers are making Covid-19 vaccines that would target more than one strain of the virus, hoping to strengthen the immunization campaign against the pathogen as it evolves.
Moderna researchers Inc.,
and Oxford University are designing the injections, known as multivalent vaccines, to protect not only against the form of the virus that is commonly circulating globally, but also against potentially contagious strains that have emerged or could in the future.
The work is one of a series of efforts that vaccine manufacturers and drug researchers are undertaking to stay ahead of variants such as that identified in the United Kingdom, South Africa and Brazil.
Research indicates that some vaccines currently in use elicit weaker immune responses against the strain found in South Africa in particular, although there is no evidence to indicate that current vaccines do not protect against the variants.
To be safe, companies are exploring strengthening the protection conferred by existing injections by adding doses, updating injections, or creating a booster. A multivalent shot is another approach in the works.
Testing of multivalent vaccine candidates in people has not yet begun. Some companies hope to start in the spring so that the vaccines will be available for use beginning in the summer.
Health experts say broad-acting vaccines could make a difference in the fight against the pandemic by blocking coronavirus mutations that could help you evade existing vaccines before widespread herd immunity is achieved.
“If there are two or three predominant strains worldwide, and infection or immunity to one does not protect against the others, we may need multivalent vaccines,” said Buddy Creech, director of the Vaccine Research Program at Vanderbilt University. .
Multivalent vaccines are a widely used weapon against other viruses, such as measles, mumps, and rubella. Some pneumonia vaccines target up to 23 strains, while most flu vaccines target four different strains of influenza.
“Nobody wants to be in a position where one variant suddenly infects everyone again.”
To defeat a variety of variants, vaccines essentially combine several different injections. As long as researchers choose the right combinations, the vaccines should work, though not if the mix spreads protection too much, vaccine experts say.
Multivalent vaccines would be especially helpful against Covid-19, virologists and vaccine experts say, if scientists can predict which mutations could spread, as influenza is done every year.
“The real question is what the virus will evolve into, and if we knew the answer, we could stop it,” said Dr. Sean Whelan, a virologist at Washington University in St. Louis, whose lab is trying to predict major mutations.
Companies began looking for multivalent Covid-19 vaccines in recent months, as research suggested emerging variants could escape the protection of currently available vaccines.
Companies may prefer to make multivalent Covid-19 vaccines, rather than tailor injections to various regions of the world with different variants.
However, multivalent vaccines are more complex to research and manufacture, which can increase company costs and the time it takes to manufacture them, vaccine experts say.
The global market for Covid-19 vaccines would be worth more than $ 15 billion if annual injections are needed to address waning protection over time and multivalent vaccines are required to avoid variants, Bernstein Research estimates.
Moderna, which is developing a vaccine specifically targeting the identified strain in South Africa, is also looking for a candidate that combines the variant-focused injection with the company’s currently used vaccine.
The combination “could ultimately be the best approach,” Moderna president Stephen Hoge said during an earnings call last month. Moderna has not specified when a study for the multivalent candidate would begin.
Novavax, which has a Covid-19 vaccine targeting the parent version of the virus in late-stage US trials, plans to begin testing a bivalent vaccine targeting the parent version of the virus as well as the variant mid-year. first identified in South Africa. Dr. Gregory Glenn, the company’s head of R&D, said on a conference call this month.
It settled on this approach after analyzing data from its clinical trials in the UK, indicating that targeting the South African variant would offer protection against other strains, a Novavax spokeswoman said.
Researchers at the University of Oxford are following a multivalent approach that includes the strains first identified in Brazil and South Africa, according to AstraZeneca AZN. 1.34%
PLC, which authorized the distribution of the shot.
Testing could begin this spring with the injection available in the summer, Dr. Mene Pangalos, AstraZeneca’s R&D executive, said in a conference call with analysts last month.
Drew Weissman, an immunologist at the University of Pennsylvania whose research contributed to the mRNA technology used by BioNTech SE BNTX 4.01%
and Moderna, said their team is working on a multivalent vaccine to cover all current and future variants.
“Nobody wants to be in a position where one variant suddenly infects everyone again, so people want to have their vaccines ready to go. We have not reached that point. So we have time to get this right, “he said in an interview.
Johnson & Johnson JNJ 0.82%
he has said he is preparing an antigen, the substance on which a vaccine relies to generate an immune response, that would target the variant that spread in South Africa.
The company, which has a recently licensed Covid-19 vaccine, has not committed to a multivalent injection, but would develop one if a variant escaped the protection of the vaccine.
which developed the first Covid-19 vaccine licensed in the US with its partner BioNTech, is only working on a vaccine targeting the South African variant. Pfizer believes that targeting just one strain is sufficient because it is crowding out other variants, so a multivalent vaccine that targets multiple strains is not necessary, said Phil Dormitzer, the drugmaker’s scientific director of viral vaccines.
However, Dr. Ofer Levy, director of the vaccine program at Boston Children’s Hospital, said that multiple variants can circulate simultaneously until one becomes the dominant strain.
Write to Jared S. Hopkins at [email protected]
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