ANAs health officials in the United States have announced a second and possibly a third person infected with a new, more transmissible strain of the SARS-CoV-2 virus, infectious disease specialists are feeling a sense of déjà vu again.
A little less than a year ago, the initial response to the coronavirus crisis was stifled by the inability to increase tests to detect the virus and contain its spread. Now, again, it is not clear how prevalent the new strain, which first appeared in the UK, may be in the USA. It is already possible and a probable case has been detected in Colorado and a case has been reported in California. But it is likely that the spread of the variant did not stop there.
“It looks a lot like that period between January 19 or more, when we had that first case in the Seattle area and six weeks later, when, suddenly, it looks like we have community broadcast in California and Seattle and who knows where else,” he said. Michael Worobey, professor of evolutionary biology at the University of Arizona. “It has that feeling.”
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Trevor Bedford, a computational biologist at the Fred Hutchinson Cancer Research Institute, told STAT that he does not believe the new variant, called B.1.1.7, is still widespread. There are 250 genetic sequences of SARS-2 virus cases from December in the United States that have been recorded in an international virus-sharing database known as GISAID; there is no B.1.1.7 among them, Bedford said. But he believes it may just be a matter of time.
“How I imagined this to work is … very similar to January, February,” he said. “There are sowing events that have taken place across the country. Some did, some didn’t … And you can imagine that it should be more likely in places like New York and Boston, with good travel connections to London, but it could have just happened to have picked up a little elsewhere. “
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Worobey agreed that the new variant is probably already spreading to various parts of the country, traveling off the radar because the United States is not doing enough sequencing of the SARS-2 virus.
“We are a little behind in terms of our genomic sequencing, both in terms of absolute numbers and in the type of delay between sampling and obtaining the strings, compared to the UK,” said Worobey. He warned that if the United States does not find the cases and spread slowly, there is likely to be the same type of rapid spread of the variant that the United Kingdom has seen.
The new variant has an unusual number of mutations, including some that appear to alter the virus’s behavior. It appears to be significantly more transmissible, increasing the rate of infection in other people.
There is no evidence so far that the variant triggers more serious diseases. But hospitals are struggling to deal with Covid patients as they are; more infections can lead to a higher mortality rate, due to the decreased quality of care.
“The death rate increases if health systems are overloaded,” said Nahid Bhadelia, medical director of the special pathogen unit at Boston Medical Center. “That’s how it works.”
Efforts are underway to try to find out how widely the new variant is spreading – one led by Worobey’s lab. His team is trying to develop an assay that can be used to test variant viruses in wastewater from community sewage systems. If the test works, he said, the laboratory will send test materials to other laboratories, test samples in its own laboratory or share the recipe for making the primers and probes so that the test is widely used.
“I really think wastewater is going to be the best way in the short term to get better control, rather than waiting for a strange laboratory like Colorado that finds one of these in an individual patient sample,” said Worobey.
The Centers for Disease Control and Prevention are also stepping up efforts to increase the sequencing of the SARS-2 virus, officials said on Wednesday.
Gregory Armstrong, who leads the CDC team that monitors variants of the virus, said the national surveillance system for the SARS-CoV-2 strain, which started in November, is being expanded to be able to handle 750 samples sent by the states for sequencing and study every week. The CDC is also working with national reference laboratories in the country, providing funding for sequencing several times more viruses. The hope is to reach around 3,500 a week, noted Armstrong.
He said experts at CDC and elsewhere do not believe that the mutations contained in B.1.1.7 will significantly undermine the protection provided by Covid vaccines in use or in production. “It can have a small impact. But keep in mind that the amount of immunity that is induced by natural infection or vaccination is likely to be large enough that a slight decrease [antibody] the title may not have any noticeable effect, ”said Armstrong.
But Bedford said that increased use of the vaccine will put additional pressure on SARS-2 viruses to mutate and try to escape the protection that the vaccine triggers.
“It is even more of an argument to try to get collective immunity more quickly and to reduce transmission through vaccination,” he said. “The sooner we can vaccinate enough people, the better we will be at preventing this variant and other future mutants from spreading.”