Covid-19 vaccines targeting several strains are in process

The work is part of a series of efforts by vaccinists and drug researchers to move forward with variants such as the one identified in the UK, South Africa and Brazil.

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 to indicate that current vaccines do not protect against variants.

To be safe, companies are exploring strengthening the protection afforded by existing shots by adding doses, updating shots, or crafting a reinforcement. A multivalent plan is another approach to the works.

Multivalent vaccine candidates in people have not yet begun testing. Some companies hope to start in the spring so the shots can be used as early as the summer.

Health experts say broad-based traits could make a difference in fighting the pandemic by preventing coronavirus mutations that could help it bypass existing vaccines before widespread herd immunity is achieved.

“If there are two or three predominant strains worldwide and one infection or immunity does not protect against the other, we may need multivalent vaccines,” said Buddy Creech, director of the University of California’s vaccine research program. Vanderbilt.

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 flu strains.

To defeat a variety of variants, vaccines are basically combined with a number of different traits. As long as researchers choose the right combinations, vaccines should work, though not if the mixture extends the protection too thin, vaccine experts say.

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

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

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

Companies may prefer to make multivalent vaccines against Covid-19, rather than adapting shots to various 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 manufacture them, vaccine experts say.

The global Covid-19 vaccine market will be worth more than $ 15 billion if annual shots are needed to cope with declining protection over time and multivalent vaccines are needed to prevent variants, according to Bernstein Research.

Moderna, which is developing a vaccine specifically targeted to the strain identified in South Africa, is also pursuing a candidate who combines the variant-centered trait with the company’s vaccine currently in use.

The combination “ultimately could be the best approach,” Moderna president Stephen Hoge said during a earnings call last month. Modern has not specified when a study for the multivalent candidate would begin.

Novavax, which has a Covid-19 vaccine targeting the original version of the virus in final-stage US testing, plans to start testing a bivalent vaccine targeting the original version of the virus in half a year, as well as the variant identified by first time in South Africa, Dr Gregory Glenn, the company’s head of R&D, said in a conference call this month.

It was established in this approach after analyzing data from clinical trials conducted in the UK, indicating that targeting the South African variant would offer protection against other strains, a Novavax spokeswoman said.

Oxford University researchers are following a multivalent approach that includes targeting strains first identified in Brazil and South Africa, according to AstraZeneca AZN 1.33%

PLC, which licensed the shot to distribute it.

Trials could begin this spring with the shot available in the summer, Dr. Mene Pangalos, an AstraZeneca 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 2.40%

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

“No one wants to be in a position where a variant suddenly infects everyone, so people want to have their vaccines ready to begin with. We have not reached this point. So we have time to do well, ”he said in an interview.

Johnson & Johnson JNJ 1.09%

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

The company, which has a recently licensed Covid-19 vaccine, has not promised to make a multivalent shot, but would develop one if a variant escaped vaccine protection.

Pfizer Inc.,

PFE 0.85%

who developed with partner BioNTech the first Covid-19 vaccine authorized in the US, is only working on a vaccine aimed at the South African variant. Pfizer believes it is enough to target only one strain, as it is eliminating other variants, so a multivalent vaccine that attacks multiple strains is not necessary, said Phil Dormitzer, chief scientist of the drug manufacturer’s viral vaccines. .

However, Dr. Ofer Levy, director of the Boston Children’s Hospital vaccination program, said several variants can circulate simultaneously until one becomes the dominant strain.

Write to Jared S. Hopkins at [email protected]