Covid-19 Vaccine Makers Take Aim at Dangerous New Strains
Pfizer, Moderna and J&J are among the companies working on new vaccines that would protect against the South Africa strain better than current shots do
Covid-19 vaccine makers are racing to create new shots that can better protect people from dangerous new strains of the coronavirus, after recent testing showed the variants present a bigger-than-expected threat.
The chase marks a new phase in vaccine research to fight off the virus, indicating it may shift into a kind of long-running contest between a changing virus and shots that can keep up, rather than a shorter effort that would once and for all derail the pandemic.
When new strains were first identified in the U.K., South Africa and Brazil, the companies said they believed their shots would still protect against Covid-19. Then several studies indicated Covid-19 vaccines, while still working, aren’t as effective against the variant that spread widely in South Africa.
Now Moderna Inc., Pfizer Inc. and its partner BioNTech SE, Johnson & Johnson and Novavax Inc. are designing new vaccines that would target variants of the virus, particularly the variant first identified in South Africa and now detected in other countries including the U.S.
On Wednesday, British drugmaker GlaxoSmithKline PLC said it was partnering with Germany’s CureVac NV in a deal worth up to €150 million, equivalent to $181 million, to develop Covid-19 vaccines that can tackle new variants, while AstraZeneca PLC and partner University of Oxford said they plan to develop a new version of their vaccine that would target variants and could be available by autumn.
The U.S. Food and Drug Administration, meanwhile, is taking steps such as requiring smaller trials in order to accelerate the review and authorization of modified vaccines.
“It highlights this arms race we have right now between getting enough people vaccinated and seeing the virus change,” said Dr. C. Buddy Creech, director of Vanderbilt University’s vaccine-research center.
All viruses mutate. Early in the pandemic researchers expressed optimism the new coronavirus wouldn’t change too significantly and vaccines in development would be able to rid the world of the virus.
Pfizer’s and Moderna’s vaccines, which were cleared for use in the U.S. in December before the variants were identified, appear to provide at least some protection against emerging strains in lab tests.
Yet they weren’t tested in humans exposed to the new strains. And vaccines from J&J and Novavax recorded lower effectiveness levels in studies in South Africa that took place after the variant was identified there, compared with their performance in other regions.
J&J’s shot, for example, was 57% effective in South Africa versus 72% in the U.S. J&J plans to seek U.S. authorization for its vaccine this week.
While the current vaccines still work, it is important to start developing potential follow-on vaccines to be prepared for even more significant mutations that could evade current shots, companies and infectious-disease specialists say.
Pfizer Chief Executive Albert Bourla said during the 2021 Davos World Economic Forum last week that there is a “high possibility” a variant would emerge rendering Covid-19 vaccines ineffective.
“It’s very highly likely that one day that will happen,” Mr. Bourla said, adding this isn’t the case right now.
The new shots would be given as booster doses after a person gets one of the original vaccines, or companies could make new vaccines that target both the common viral strain and one or more of the new variants.
It would be akin to the tweaks that companies make each year to seasonal influenza shots to target a specific flu strain.
Makers of flu shots use the same basic ingredients of a vaccine but alter it depending on which strain is expected to be predominant. Because of this process, flu shots don’t undergo full-scale clinical trials each year.
Like flu shots, Covid-19 vaccines could become a sizable market for drugmakers beyond the pandemic emergency period if they have to be modified regularly.
Pfizer anticipates $15 billion in Covid-19 vaccine sales this year. Sales could prove durable, Mr. Bourla told analysts Tuesday, because people will likely need booster shots, either to stay protected against the virus or to combat emerging variants.
Pfizer—which had waited longer than most other vaccine makers to announce it was pursuing a new shot, should it be needed—said Tuesday it would study if using a booster shot provides additional protection, and it is tweaking its vaccine so it could guard against the strains found in Brazil and South Africa.
Pfizer hasn’t decided whether it would test a new vaccine in people, but would aim to finish any study in 100 days, Mr. Bourla said in an interview. “We don’t want to develop a vaccine if we don’t need to,” he said. “But we want to be able to develop it with the speed of light if there is a need.”
Moderna President Stephen Hoge said the company will monitor new variants and develop strain-specific vaccine booster shots if necessary. Within a few months, Moderna plans to start studying in people a booster shot targeting the variant first identified in South Africa.
Novavax is manufacturing some of the variant proteins for use in potential new vaccines, including the strain seen in South Africa, said Gregory Glenn, the company’s head of R&D.
J&J is preparing an antigen—the substance that a vaccine relies upon to induce an immune response—for testing that would target the variant that spread in South Africa, according to Mathai Mammen, head of research and development at J&J’s pharmaceutical unit.
“We’re acting in anticipation of a variant being a potential problem,” he said on a conference call with reporters last week.
Vaccine makers are focused initially on the variant first identified in South Africa because it is more contagious and has shown signs of evading the effects of the original vaccines and some treatments.
The variant that spread widely in South Africa has a large number of mutations in the spike protein, which researchers say may account for the reduced potency seen for some of the vaccines.
Pfizer and Moderna say they can modify their vaccines to target new strains fairly quickly because they can simply insert the genetic code of a new virus strain into the same basic building blocks used to make their original vaccines.
Their vaccines, using messenger RNA technology, don’t require the growth of viral material or proteins as some other vaccine types do.
GSK and CureVac are also using mRNA technology to develop their vaccines, one of which the companies say could be ready for use in 2022. “The increase in emerging variants with the potential to reduce the efficacy of first-generation Covid-19 vaccines requires acceleration of efforts to develop vaccines against new variants to keep one step ahead of the pandemic,” the companies said.
It also shouldn’t be difficult to tweak vaccines from J&J, AstraZeneca and Novavax because of the new technologies used to make those shots, though the process could take slightly longer, said Robert Garry, professor of microbiology and immunology at Tulane Medical School.
The FDA plans to speed up the approval process for such follow-on vaccines by requiring smaller, shorter clinical trials demonstrating they induce certain immune responses, rather than the large efficacy trials that were conducted for the original vaccines, Peter Marks, director of FDA’s biologics center, said Friday in an online discussion hosted by the American Medical Association.