As scientists try to track the spread of a new, more infectious coronavirus variant around the world — finding more cases in the United States and elsewhere this week — they are also keeping an eye on a different mutation with potentially greater implications for how well Covid-19 vaccines work.
The mutation, identified in a variant first seen in South Africa and separately seen in another variant in Brazil, changes a part of the virus that your immune system’s antibodies get trained to recognize after you’ve been infected or vaccinated. Lab studies show that the change could make people’s antibodies less effective at neutralizing the virus. The mutation seems to help the virus disguise part of its signature appearance, so the pathogen might have an easier time slipping past immune protection.
It’s not that the mutation will render existing vaccines useless, scientists stress. The vaccines authorized so far and those in development produce what’s called a polyclonal response, generating numerous antibodies that home in on different parts of the virus. Changes to any of those target sites raise the possibility that the vaccines would be less effective, not that they won’t work at all.
“With one mutation or even three mutations, it’s expected the antibodies will still recognize this variant, though they might not recognize it as well as other variants,” said Ramón Lorenzo-Redondo, a molecular virologist at Northwestern University’s Feinberg School of Medicine.
Essentially, the mutation is getting attention because it appears more likely to have some effect on vaccines than other mutations that have emerged, though scientists are still trying to test that hypothesis. The more contagious variant raising global alarms, which was first seen in the United Kingdom and is referred to as B.1.1.7, is not thought to have mutations that will greatly affect vaccines, the evidence so far indicates.
“We need to be monitoring for these mutations,” said Jesse Bloom, an evolutionary virologist at Fred Hutchinson Cancer Research Center, who with colleagues published a paper about this specific mutation, known as E484K, this week.
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