Researchers are still debating whether the new variants could undercut the effectiveness of these first-generation COVID-19 vaccines. But some vaccine developers are charging forward with plans to update their shots so that they could better target the emerging variants, such as those identified in South Africa and Brazil. These lineages carry mutations that seem to dampen the effects of antibodies crucial to fending off infection. Researchers are also considering the possibility that vaccines against the coronavirus might have to be updated periodically, as they are for influenza.
The best and most immediate way to combat the threat of emerging variants is still probably to quickly vaccinate as many people as possible with current shots, says Mani Foroohar, a biotechnology analyst at the investment bank SVB Leerink in Boston, Massachusetts: “We need to get vaccines in arms and to smother this virus before it blows up in our face again.”
But Foroohar and others expect that, in the future, a bevy of new vaccines will emerge to take the COVID variants head on. Nature explores the open questions about updating the world’s coronavirus vaccines.
Labs worldwide are racing to understand the threat that emerging coronavirus variants pose for vaccines. But early insights from these studies are mixed and incomplete. A variant identified in late 2020 in South Africa, called 501Y.V2 (also known as variant B.1.351), is among the most worrying. Lab assays have found that it carries mutations that sap the potency of virus-inactivating ‘neutralizing antibodies’ that were made by people who received either the Pfizer or Moderna RNA vaccines.
Whether these changes are enough to lower the effectiveness of those vaccines is not clear, says Subbarao. “That is the million-dollar question, because we don’t know how much antibody you need.” Other immune responses that vaccines prompt might help to protect against the effects of variants.
But on 28 January, biotech firm Novavax released data from clinical trials showing that its experimental vaccine, designed to combat the original virus, was about 85% effective against a variant identified in the United Kingdom — but less than 50% effective against 501Y.V2. That drop is concerning, say researchers, because it indicates that 501Y.V2 and other variants like it can cause a significant drop in vaccines’ effectiveness.
A Guest Editorial