Covid-19 vaccines targeting multiple strains are underway

The work belongs to a series of efforts that vaccine manufacturers and drug researchers are undertaking to anticipate variants such as the one identified in the United Kingdom, South Africa and Brazil.

The research indicates that some vaccines currently in use generate weaker immune responses against the strain found in South Africa in particular, although there is no evidence indicating that current vaccines do not protect against variants.

For safety, companies are exploring strengthening the protection afforded by existing injections, adding doses, updating the injections or creating a backup. A multivalent take is another approach in development.

The testing of multivalent candidate vaccines in people has not yet begun. Some companies hope to start in the spring so that the photos can be made available for use in the summer.

Health experts say broad-acting injections can make a difference in the fight against the pandemic, blocking mutations in the coronavirus that can help you escape existing vaccines before generalized herd immunity is achieved.

“If there are two or three strains prevalent worldwide, and infection or immunity to one does not protect against the others, then 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.

To defeat a variety of variants, vaccines basically mix a series of different injections. As long as researchers choose the right combinations, vaccines should work, although the mixture does not spread the protection too thin, vaccine experts say.

Multivalent vaccines would be especially useful against Covid-19, say virologists and vaccine experts, if scientists could predict which mutations could spread, as is done with the flu each year.

“The real question is where the virus is going to evolve, and if we knew the answer to that, we could stop it,” said Dr. Sean Whelan, a virologist at Washington University in St. Louis, whose laboratory is trying to predict important mutations.

Companies have started looking for Covid-19 multivalent vaccines in recent months, as research suggested that emerging variants could escape protection from currently available vaccines.

Companies may prefer to make multivalent Covid-19 vaccines, rather than tailoring vaccines to different regions of the world with different variants.

However, multivalent vaccines are more complex to research and manufacture, which can increase the company’s costs and the time it takes to produce them, vaccine experts say.

The global Covid-19 vaccine market would be worth more than $ 15 billion if annual injections were needed to deal with declining protection over time and multivalent vaccines were needed to avoid variants, Bernstein Research estimates.

Moderna, which is developing a vaccine targeting the strain identified in South Africa specifically, is also looking for a candidate who would combine the injection focused on the variant with the company’s vaccine currently in use.

The combination “may ultimately be the best approach,” said Moderna’s president Stephen Hoge during a results conference call last month. Moderna did not specify when a study would begin for the multivalent candidate.

Novavax, which has a Covid-19 vaccine targeting the original version of the virus in the final stage of testing in the United States, plans to begin testing a bivalent vaccine that targets the original version of the virus as well as the variant in the middle of the year. First identified in South Africa, Dr. Gregory Glenn, the company’s head of R&D, said in a conference call this month.

She decided to take this approach after analyzing data from her clinical trials in the UK, indicating that targeting the South African variant would offer protection against other strains, a Novavax spokesman said.

Oxford University researchers are looking for a multivalent approach that includes targeted strains initially identified in Brazil and South Africa, according to AstraZeneca AZN 1.30%

PLC, which licensed the shot for distribution.

Testing may begin this spring with the injection available in the summer, said Dr. Mene Pangalos, R&D executive at AstraZeneca, 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 2.50%

and Moderna, said his team is working on a multivalent vaccine to cover all current and future variants.

“Nobody wants to be in a position where a variant suddenly infects everyone again, so people want to have their vaccines ready for use. We have not yet reached that point. So we have time to do it right, ”he said in an interview.

Johnson & Johnson JNJ 1.08%

he said he is preparing an antigen – the substance on which a vaccine depends to generate an immune response – that would target the variant that has spread across South Africa.

The company, which has a newly authorized Covid-19 vaccine, has not committed to a multivalent injection, but would develop one if a variant escapes vaccine protection.

Pfizer Inc.,

PFE 0.89%

who developed with the partner BioNTech the first vaccine Covid-19 authorized in the USA, is working only on a vaccine aimed at the South African variant. Pfizer believes it is sufficient to target only one strain because it is eliminating other variants, so a multivalent vaccine that attacks multiple strains is not needed, said Phil Dormitzer, the pharmaceutical’s scientific director of viral vaccines.

Even so, Ofer Levy, director of the vaccine program at Boston Children’s Hospital, said that several variants can circulate simultaneously until one becomes the dominant strain.

Write to Jared S. Hopkins at [email protected]