Johnson & Johnson JNJ -0.19%
is working on several next-generation versions of its Covid-19 vaccine that may be needed to reinforce protection against some of the variants of the coronavirus that have emerged.
J&J Chief Executive Alex Gorsky said on Thursday that he was hopeful that the newly authorized J&J vaccine and other current Covid-19 vaccines will provide some protection against new variants, but booster doses or modified versions of original vaccines may be needed.
“We need to be prepared,” said Gorsky on Thursday. “We must prepare for the worst and hope for the best.”
J&J’s original Covid-19 vaccine was authorized by US regulators in late February. In a final stage test, the injection was 66% effective in protecting people in a large international study of moderate to severe Covid-19 disease.
But its effectiveness was less so in the testing part in South Africa, where a variant has spread that has shown resistance to vaccines designed to work mainly against an earlier version of the virus that circulated widely last year.
Other companies, including Moderna Inc.
they are also taking steps to develop and test modified vaccines that can better target variants.
Researchers are exploring whether some variant-targeted vaccines should be administered as a booster injection or as part of a “multivalent” vaccine that also targets other strains.
Laboratory tests and clinical trials have generally shown that the original Covid-19 vaccines retain much of their protection against a highly transmissible variant first identified in the UK
Its potency appears low against the strain first identified in South Africa, although the J&J vaccine was solidly effective in a clinical trial in preventing serious and critical cases of Covid-19 there.
Some variants of the virus “are more worrying because they result in fundamental mechanical changes that can have an impact, for example, on the transmission rate or potentially even on morbidity or mortality,” said Gorsky during an online discussion hosted by the New York Economic Club.
He said the need for booster doses or modified vaccines will depend on how the variants will evolve in the coming months, but the company is preparing now. “We are working on several of the next generation of vaccines,” he said.
J&J, based in New Brunswick, NJ, is also conducting a study to see whether two doses of its vaccine are more effective than the currently authorized single dose regimen. The results are expected later this year.
J&J executives said earlier that they were working on a potential vaccine to target the variant first identified in South Africa, but it was still unclear which variants it would focus on for further development.
A J&J vaccine targeting a variant can be particularly useful in countries that have easier storage and handling requirements for J&J vaccine technology. The injection can be kept stable in a refrigerator for a longer period than the messenger RNA vaccines from Moderna and Pfizer Inc.,
which could be useful in low-income countries with more limited cold chain distribution infrastructure.
As highly transmissible variants of the coronavirus spread around the world, scientists are racing to understand why these new versions of the virus are spreading more quickly and what this could mean for vaccine efforts. New research says the key may be the protein spike, which gives the coronavirus its unmistakable shape. Illustration: Nick Collingwood / WSJ
Write to Peter Loftus at peter.loftus@wsj.com
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Published on March 19, 2021, print edition as ‘J&J aims to modify doses for variants.’