As coronavirus mutations undercut vaccine optimism, US scientists warn of a long fight

Covid-19 vaccines hold hope of ending the pandemic – but mutations that are at least partially resistant to antibody treatment are spreading worldwide

Drug makers are looking at bivalent vaccines but scientists say Covid-19 could morph into something like influenza that requires periodic booster shots

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A pharmacy manager draws up a Covid-19 vaccine at a mass vaccination site in Washington state, US, as new variants threaten the efficacy of existing jabs. Photo: Reuters

Published: 4:00pm, 30 Jan 2021Updated: 11:02pm, 30 Jan 2021

The world could be on the verge of having two more vaccines to fight the Covid-19 pandemic, but virus variants popping up worldwide are forcing companies that make the shots to develop boosters for a disease that could remain active for years.

Vaccines made by Moderna, the Pfizer-BioNTech partnership and Sinovac are already in use. Meanwhile, new studies show that two more – from Johnson & Johnson and Novavax – pack potent punches against early forms of the virus, potentially paving the way for quick authorisations in the US for J&J’s vaccine and in the UK for Novavax’s shot. That is the good news, offering the promise of ending a pandemic that’s killed more than 2 million people worldwide.

Now comes the bad news: Mutations that likely confer partial resistance to vaccines and antibody treatments are now prevalent in both South Africa and Brazil, and threatening to spread worldwide.

The J&J shot was found in a late-stage trial to be 72 per cent effective in the US, but that fell to 57 per cent in studies done in South Africa. Novavax’s shot, 89 per cent effective in the UK, was only 49 per cent effective in South Africa.

Even before these results, laboratory tests on other vaccines suggested the shots would likely be less potent against the new South Africa variant. But what that meant in terms of illness in the real world was unclear. The new results offer a clear indication that vaccines will not work as well against at least one of the emerging mutations.

“Now we have the real world clinical consequences, and we can see that we are going to be challenged,” said Anthony Fauci, the top US infectious disease expert, on a conference call on Friday.