Covid-19 vaccines targeting multiple strains are in the works

The work is part of a series of efforts that vaccine manufacturers and drug researchers are undertaking to stay ahead of variants such as those identified in the UK, South Africa and Brazil.

Research indicates that some vaccines currently in use generate a weaker immune response against the strain found particularly in South Africa, although there is no evidence that current vaccines do not protect against variants.

To be on the safe side, companies are looking into bolstering the protection offered by existing shots by adding doses, updating the shots, or creating a booster. A multi-value recording is another approach in the making.

Testing of multivalent vaccine candidates in humans has not yet begun. Some companies hope to start in the spring so shots can be available for use as early as the summer.

Health experts say the broad-ranging shots could make a difference in the pandemic battle by stunting mutations in the coronavirus that could help bypass existing vaccines before broad herd immunity is achieved.

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

Multivalent vaccines are a common weapon against other viruses, such as measles, mumps and rubella. Some pneumonia vaccines target as many as 23 strains, while most flu shots target four different flu strains.

To beat different variants, the vaccines essentially mix a number of different shots. As long as researchers choose the right combinations, the vaccines should work, but not if the mixture spreads protection too thinly, 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 happens every year with the flu.

“The real question is what the virus is evolving into, and if we knew the answer to that, then we could stop it,” said Dr. Sean Whelan, a virologist at Washington University in St. Louis whose lab is trying to predict key mutations. .

Companies have begun to look for multivalent Covid-19 vaccines in recent months, as research suggested emerging variants could escape protection from the vaccines currently available.

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

Still, multivalent vaccines are more complex to research and manufacture, which can increase operating costs and the time it takes to make them, vaccine experts say.

The global market for Covid-19 vaccines would be worth more than $ 15 billion if annual injections are required to address declining protection over time and multivalent vaccines are needed to prevent variants, Bernstein Research estimates.

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

The combination “may ultimately be the best approach,” said Moderna president Stephen Hoge during an earnings call last month. Moderna did not specify when a study would start for the multivalent candidate.

Novavax, which has a Covid-19 vaccine targeting the original version of the virus in late-stage US testing, plans to begin testing a bivalent vaccine targeting the original version mid-year of the virus and on the variant first identified in South Africa Dr. Gregory Glenn, the company’s R&D chief, said during a conference call this month.

It decided on this approach after analyzing data from its UK clinical trials, indicating that targeting the South African variety would provide protection against other species, a Novavax spokeswoman said.

Researchers at the University of Oxford are pursuing a multivalent approach, including targeting strains first identified in Brazil and South Africa, according to AstraZeneca AZN. 1.30%

PLC, which licensed the recording for distribution.

The trials could begin this spring with the shot available in the summer, said Dr. Mene Pangalos, an AstraZeneca R&D manager, during 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 3.07%

and Moderna, said his team is working on a multivalent vaccine for 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 get this right, ”he said in an interview.

Johnson & Johnson JNJ 1.01%

has said it prepares an antigen – the substance a vaccine relies on to trigger an immune response – that would target the variant that spread in South Africa.

The company, which has a recently approved Covid-19 vaccine, has not committed to a multivalent injection, but would develop one if a variant escaped protection from the vaccine.

Pfizer Inc.,

PFE 0.83%

which, together with partner BioNTech, developed the first Covid-19 vaccine approved in the US, is only working on a vaccine targeting the South African variant. Pfizer believes targeting just one strain is enough because it displaces other variants, so a multivalent vaccine targeting multiple strains isn’t necessary, said Phil Dormitzer, chief scientific director of viral vaccines at the drug manufacturer. .

Still, 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]