The discovery of several new variants of the coronavirus that may spread more easily, including a mutation that took hold in the Bay Area in December, makes it even more urgent to fix the nation’s troubled vaccination rollout — before the evolving virus causes another surge or learns to evade vaccines.
Throughout the yearlong pandemic, public health experts have advised that beating the virus was a marathon, that it would take many months of commitment to social distancing measures to win. That’s still true. But in many ways the race has intensified in recent weeks: between a virus that is spinning out new mutations that could make it harder to contain and an immunization campaign marked by repeated fumbles.
“We’re really in a race now,” said Dr. Charles Chiu, the UCSF virologist who identified the L452R variant that’s blown up in parts of the Bay Area over the past month. “This only increases our urgency to mass vaccinate the population before additional variants evolve and emerge.”
One worrisome aspect: The more the coronavirus is circulating in the community, the more chances it has to mutate and develop into new variants. And there has never been more virus in California and the United States than now — and many other countries are also struggling to contain it, creating more risk in an interconnected world.
“By letting the virus run rampant, we are allowing it to accumulate a lot of mutations. And some of those may be advantageous for the virus,” said Dr. Catherine Blish, an infectious disease expert at Stanford. “The best thing we can do right now is deliver the vaccine as quickly as possible to as many people as possible to decrease that total infection burden, so we are accumulating fewer mutations.
“We can’t stop the virus from mutating,” she said. “But we really can gain the upper hand here.”
The U.S., and California specifically, is in a precarious spot in the pandemic. The country passed 400,000 total deaths from COVID-19 on Tuesday, and in California, daily cases and deaths have been overwhelmingly high for weeks.
Meanwhile, the immunization campaign that the country needs to escape the pandemic has been littered with problems, both at the state and national level — most recently with 330,000 Moderna doses being taken out of circulation in California due to concerns over allergic reactions.
A new variant, or more than one, has the potential to make a bad situation worse. If a more infectious version of the virus takes over, it could reinvigorate a surge that is just starting to level off. And it could potentially undermine immunization efforts if the vaccines are less effective against it.
The immediate threat to the Bay Area and the rest of the state from new variants isn’t yet clear. The highly infectious B117 variant that’s spreading widely in the United Kingdom has been identified in Southern California, but only in a few dozen cases. But the Centers for Disease Control and Prevention warned last week that the variant could become the dominant version of the virus in the U.S. as soon as March, and that it could fuel a massive new surge in cases.
The L452R variant, whose presence in California was announced Sunday, appears to have a foothold in parts of the state and has been tied to multiple large outbreaks in Santa Clara County, but scientists don’t know for sure that it’s more infectious than the virus type that has circulated in California to date. If L452R turns out to be more infectious, it’s unclear how the competition between it and the B117 variant would play out.
The B117 variant is not able to evade vaccines, but scientists don’t know about the L452R variant. Neither appears to cause more serious illness — though a more infectious virus would inevitably cause more sickness and death.
The emergence of the two new variants in California, along with at least two more spreading in other parts of the world, raises fresh concerns about what mutations could still come along or may already be here and simply haven’t been detected yet. Experts say the arrival of these variants makes it clearer than ever that the pandemic must be contained quickly.
“With 3,000 or 4,000 people a day dying (in the United States) we were already in a race with the virus that we knew, and now we’re going to add another element,” said Dr. Robert Wachter, chair of the Department of Medicine at UCSF. “It’s like you’re in a race and all of a sudden the person you’re racing against is 50% faster.
“Once we had two amazingly effective and safe vaccines, it really was how fast can you get this into people’s arms,” he said. “Not only because of the threats that were obviously quite clear, but the emerging threats that will come out the longer this takes.”
The coronavirus, like all other so-called RNA viruses, mutates regularly. But the COVID-19 virus tends to mutate at a slower pace than many other viruses, adopting only one or two mutations a month. Most of those mutations have little or no effect. Some make the virus less likely to survive. Other mutations make it slightly more or less infectious. Or they change the way the virus interacts with the body’s immune system, making it a more challenging target for natural immunity or a vaccine.
When enough mutations build up, a new variant emerges that is genetically separate from its parent and behaves in a notably different way. The B117 variant has 23 mutations and is much more infectious than its parent. Another variant found in South Africa also appears to spread more easily.
The L452R variant has five mutations. Infectious disease experts worry that it may also be more infectious, if only because of how quickly it’s taken hold in the region and other parts of the state. But they don’t yet know how those mutations affect its behavior.
That so many variants have been detected in such short order raises another overarching concern: This coronavirus is mutating faster than most scientists thought it would. That’s likely due in part to simple math — there is so much virus circulating around the world right now that even at a slow mutation rate, the alterations are going to pile up.
Public health experts say that for now, there’s no evidence that the new variants aren’t susceptible to the vaccines. But laboratory tests suggest that some variants, including L452R, have a mutation that may make the vaccines less effective. Much more research needs to be done, Chiu and others said.
The good news is that the vaccines being used now can be easily modified to match a new variant, infectious disease experts said. That’s not an ideal situation, though — it would certainly complicate an already chaotic vaccination campaign. And it would require a much more aggressive surveillance effort to identify new variants and determine how well the vaccines work against them.
The possibility of a variant evading the vaccines could become more pronounced as more people are immunized, infectious disease experts say. Vaccinating people puts pressure on the virus to mutate for its survival. Random mutations that let the virus escape the vaccine will be favored — and more likely to replicate.
“If you have a circulating virus that now encounters immune control (from a vaccine), you will with much higher likelihood help evolve variants that will be adapted and will grow better,” said Dr. Melanie Ott, director of the Gladstone Institute of Virology, an independent research group in San Francisco.
That also means that a clumsy vaccination program that leaves large gaps in protection could make it more likely for a variant to emerge that can evade the vaccines, she said. Much of the world has yet to access the vaccines, so even if the United States tamed the virus, it would need to be vigilant about the virus arriving across borders.
Until herd immunity is attained and the virus stops circulating, variants will remain an issue.
“If we are too slow, we will have potentially variants take over that may be less susceptible to the vaccine. We will have a situation where the vaccine is partially inactive,” Ott said. “We need to get as many people vaccinated as quickly we can, so we have as little virus circulating as possible.”