There is growing concern among public health experts that highly contagious variants of the coronavirus may hamper efforts to control the rise in new cases of COVID-19 that hit California.
Twenty-four new cases of a mutated SARS-CoV-2 strain, known as “B117” and first identified in the UK in December, were discovered in San Diego County on Tuesday, bringing the total to 32 in the state .
“We anticipate that there will be others identified,” Governor Gavin Newsom said at a news conference on Monday.
The virus variant – which is less detectable by current test methods, but up to 80% more person-to-person than previous mutations – could bring the current COVID-19 crisis in California to a breaking point and threaten efforts to reopen the economy and schools.
“If the new variant succeeds in acquiring a mutation that hides it from PCR (polymerase chain reaction) tests, we are heading for the worst perfect storm possible,” said Fyodor Urnov, director of the UC Berkeley Innovative Genomics Institute, whose laboratory tracks changes in the genetic material of viruses.
The new variant acquired mutations much more quickly than scientists expected. He has gone through 23 separate variations so far, 17 of which are linked to the building blocks of the proteins that make up the virus.
Newsom said California plans to increase its contact tracking and disease investigation efforts to track the new strain, which has also been identified in New York, Georgia, Colorado and Florida.
“We haven’t yet detected the new strain in San Francisco,” said Dr. Grant Colfax, the city’s top health consultant. “It certainly wouldn’t be surprising if and when it was detected.”
California has partnered with UCSF to conduct aggressive genomic testing – running about 5,000 to 10,000 tests a week to identify the different mutations in the virus that circulate in the state.
Charles Chiu, director of viral diagnostics at UCSF, said the strain of the UK is likely to be in circulation in the United States, but has so far been identified in states with robust genomic sequencing testing programs.
“Current data suggests that this is a variant that is not currently prevalent in the United States,” said Chiu. “It is the minority of strains that circulate in the United States. That said, it can change very quickly. In the UK, it went from 5% to 60% of cases in three weeks. That is why it is very important for us to remain vigilant. “
More contagious
The UK variant, which is believed to have appeared for the first time in September, is more contagious, but “it is no longer serious in terms of the impact on your condition,” said Newsom.
Public health officials believe that the mutations, including some changes in crucial peak proteins, allow the virus to bind more strongly and enter human cells more easily.
“It’s a little more sticky than the COVID virus we’ve seen,” said Dr. Mark Ghaly, California’s chief health officer.
More cases may mean that fewer people have access to urgent medical care, especially since California hospitals have an extremely low number of beds in intensive care units.
“In addition to an existing pandemic, it can make things worse,” said Chiu.
Health officials in Britain have also suggested that the B117 variant carries mutations that make children so susceptible to being infected as adults.
“We haven’t established any causality in that, but we can see it in the data,” said Neil Ferguson, professor and infectious disease epidemiologist at Imperial College London. “We need to collect more data to see how it goes from here.”
Britain closed its schools for the next six weeks as the country handles a record number of COVID-19-related hospitalizations.
More difficult to detect
Because the virus is more difficult to detect – due to a mutation in part of the spike protein gene that requires more stringent testing to become identifiable – it can impair the ability of schools in the bay area to depend on rapid antigen tests to examine reliably asymptomatic students and staff.
“The virus more or less erased your fingerprints,” said Urnov.
A change in the virus’s genetic code, in particular, called “69-70del,” has helped to evade detection by the immune system in some people, according to studies conducted in the UK
Dr. Nicholas Moss, Alameda County health officer, said he is concerned about the new variants, but not too much.
“Variants have emerged over time, it’s part of how these organisms work,” he said. “The data from England that I saw suggests that this one spreads a little better. How much better is an area for exploration. The circumstantial evidence is quite worrying, the direct evidence is still limited. “
He said it is also unclear how widespread the variant is in the United States, although it has infected more people than reported cases so far. And he said it was too early to say whether the UK variant, or some other mutation, helped fuel the current rise in cases on the West Coast.
“I have nothing to suggest that this is causing a sudden increase in any part of the United States,” he said. “We may find that something similar has driven what we see here on the West Coast in recent weeks, be it the UK variant or another variant.”
Variants versus vaccines
Another variant discovered in South Africa known as “501Y.V2”, which quickly became the dominant strain in the country’s coastal areas, is also causing concern. Health experts fear that developing vaccines may not be effective against it.
“This is the most pressing issue we face now,” said Dr. Richard Lessells, an infectious disease specialist who is working on genomic studies of the variant in the country, to the Associated Press on Monday. “We are running experiments in the laboratory urgently to test the variant.”
The strain has so far been identified in the United Kingdom, Finland, Switzerland, Japan and Australia.
“The way you fight something that tends to change is that you have more than one weapon,” said Urnov. “We have more than one test. We have more than one vaccine. For now, considering that there is a wide range of vaccines being developed, we have good hopes that it is not globally resistant. “
None of the variants were detected in the Bay Area, but Chiu said his laboratory is actively analyzing data from the region.
In the meantime, he said the best way to stem the spread of new strains is to continue to follow the old mitigation measures: masking, physical distance and good hand hygiene.
“If you’re here, there may still be a window of time to get you under control,” he said.
Chronicle reporter Erin Allday contributed to this article.
Aidin Vaziri is a writer for the San Francisco Chronicle. Email: [email protected]