As vaccine rollouts ramp up—or in some cases, stumble ahead—in countries across the world, the SARS-CoV-2 strain has rolled out some new features of its own, primarily in the form of rapid genetic mutations. Some evidence indicates variants of recent months have made the virus more infectious, or in one case, possibly more deadly.
Virus variants are inevitable and often benign. The new coronavirus has likely mutated countless times without attracting the attention of epidemiologists. But new strains identified in the U.K., South Africa, Brazil, and California have given some infectious disease experts pause.
Several studies indicate that the strain known as the B117 variant, prevalent in the U.K., may be as much as 70 percent more transmissible than the original virus. Two analyses in California suggested that a new strain on the West Coast, called B.1.426, made up a quarter of the infections they examined. As the news whipsaws between infection spikes and inoculation efforts, it can seem like the world has entered a race between variant and vaccine.
“The change through mutation is quite rapid,” said Dr. Irwin Redlener, pediatric physician and disaster preparedness adviser to New York City Mayor Bill de Blasio. “We don’t know where it’s going. This is the reality, that we don’t know what to expect. The thing that we’re more worried about is that it could mutate to become resistant to the vaccines or partially resistant to the vaccines. That would be horrendous. We could make amendments to the vaccine, but it would slow everything down.”
Overall, the arrival of new, threatening strains should not change the average person’s behavior, three epidemiologists and public health advisers told the Daily Beast. “In terms of vaccines and mitigation, this doesn’t change the mitigation strategies because we know the mitigation works,” said Dr. Arnold Monto, University of Michigan epidemiologist and professor of Public Health. “But it just means that we have to be all the more serious about following these kinds of rules.”
“I think primarily this reinforces the urgency of every aspect of the pandemic response,” echoed Dr. Joshua Sharfstein, vice dean at the Johns Hopkins Bloomberg School of Public Health. “Not just vaccination, but also testing contact tracing, precaution taking, and general vigilance… it will take much more than vaccinations, because we don’t have enough vaccines overall in the short term.”
The U.K. Strain
Health officials in the U.K. first announced detection of a new strain in mid-December—just one week after it became the first country in the world to start administering a vaccine. In a press conference, National Health Secretary Matt Hancock revealed that the new mutation had been observed in more than 1,000 patients there, prompting a new wave of strict lockdowns across the country. The strain was thought to date back to mid-September. By late December, its spread correlated with a massive uptick in the number of COVID-19 infections throughout the county.
The phrase “more infectious” can be misleading, said Monto. Data on the new strain does not tell us, for example, that someone exposed to it will become infected faster than someone exposed to the old strain under identical conditions. It refers specifically to the rate at which the viruses reproduce.
“Let’s look at this in terms of what we know,” said Monto. “What we know is that this virus replicates better. In an individual, it takes less of this virus to cause an infection. How do we know this? We don’t know about this in terms of ‘people in a room and how many get infected with one variant versus the other.’ But what is very clear is that this virus is more efficient and has taken over versus the old virus. That tells us that it has some kind of an advantage in reproducing.”
On Friday, British Prime Minister Boris Johnson announced in a press conference that the dominant variant there could be as much as 30 percent more deadly than the original. The conclusions came from a paper published by the New and Emerging Virus Threats Advisory Group—a study that was, Monto pointed out, based on a very small number of patients in just a handful of settings.
“Lots of other things could be related to an increase in mortality,” he said, “including when you have, as they do in the U.K., greater numbers of people under care. It’s based on small numbers, so we really can’t say anything right now. We can’t speculate.”
“It was a pronouncement that he made,” Redlener said of Johnson raising the alarm. “There wasn’t really much evidence to go on. But he drew a conclusion and went public with it... For now, I’ll say Boris Johnson should have held his statement until there was more evidence.”
The South Africa Strain
Not long after the U.K. strain was first announced, a variant called B.1.351 emerged in South Africa. The new strain shared some mutations with its British predecessor, according to the CDC. It also seemed to have a higher rate of transmission. Most concerning about the South African strain, however, was a new mutation in its genetic code that some experts feared could reduce the efficacy of COVID-19 vaccines. Some preliminary studies—few of them peer-reviewed—found that the mutation E484K in the South African variant limited the effectiveness of antibodies by up to 50 percent.
“It’s definitely a concern,” Redlener said, referencing a report on the studies from NBC’s Richard Engel. “It’s a concern because a legitimate scientist mentioned it. What we don’t know is how reliable his studies were that drove him to that conclusion.”
Monto found the conclusions less alarming, noting that the studies drew from a small body of research and very few real world cases. “The bottom line is that they are trying to see in a lab if the blood from vaccines neutralize the variants as well as they do the original virus,” said Dr. Monto. “It looks like they are and to date now there are several papers. One says their test is good. Another says it’s not quite as good, but still okay.”
Another new variant was detected in Japan among four travelers from Brazil, according to the CDC. While relatively less is known about the Brazilian variant, Reuters reported Friday that the new strain accounted for nearly half of the new infections in Manaus, the largest city in the Brazilian state of Amazonas.
Last summer, a strain of SARS-CoV-2 emerged in Denmark in association with the country’s mink farming industry, according to the WHO. The country killed 17 million minks to prevent the virus from spreading to humans.
In California, scientists found a new variant in late December, not long after the state underwent its deadliest surge of the pandemic. According to the Los Angeles Times, two research groups observed the new form while looking for evidence that the U.K. strain had traveled west. Also highly transmissible, it now appears to be the fastest-growing variant in the state. In spite of the discovery, local officials and media have largely placed blame on residents, whom they claim have stopped adhering to lockdown guidelines.
“It’s a very complicated question—what is causing an outbreak in a particular place,” Redlener said. “A lot has to do with basic compliance. But on top of that there may be some other strains there that just haven’t been identified. We’re operating in the dark on a lot of stuff. It’s a lot of guesswork and speculation. We just have to keep searching.”