Yes, a new version of Omicron is spreading on at least four continents. But, no, this should not be a cause for panic, Massachusetts scientists said Tuesday.
Unlike two years ago when everyone was first learning about COVID-19, there are now many tools to combat the disease, and like its cousin, the omicron BA.2 is expected to remain relatively mild.
"I don't think it's going to cause the degree of chaos and disruption, morbidity and mortality that BA.1 did," said Dr. An infectious disease specialist at Massachusetts General Hospital in Boston. Jacob Lemieux said. "I am cautiously optimistic that we will continue to move to a better place and hopefully one where each new edition of news is not on the horizon."
While COVID-19 cases have started to decline in places like Massachusetts, where Omicron hit hard late last year, BA.2 cases are rising in the Philippines, India, Denmark and South Africa, Lemieux said. . Cases have also been reported in the United States - so far in California, New Mexico, Texas and Washington state.
It is not yet clear whether BA.2 is pushing out the original Omicron version, now called BA.1, he said.
For example, in Denmark, the rise of BA.2 coincides with the fall of BA.1, but they are currently split approximately 50–50, so "it is not clear which of these variants is driving the outbreak." It is," Lemieux said.
Meanwhile, in South Africa, where cases dropped dramatically after a massive surge around Thanksgiving, BA.2 is now more prevalent than BA.1.
"What we don't know and still have almost no idea how it will affect the number of cases, hospitalizations, deaths," he said.
Jeremy Luban, professor of molecular medicine, biochemistry and molecular pharmacology at UMass Medical School, said scientists still know much less about the transmittance of BA.2 than BA.1.
Lemieux, Luban and other medical experts made their comments Tuesday on a weekly call with the media organized by the Massachusetts Consortium on Pathogen Readiness.
It is too early to say whether BA.2 will outlive the protection provided by vaccines or existing drugs, Luban said.
Like the original Omicron, the new version has a lot of mutations, including about 20 in the region targeted by most vaccines. Mutations in BA.1 have also not been found in BA.2, which may limit the effectiveness of the monoclonal antibody, he said.
"We don't know what the significance of these mutations will be, especially in a population that has already suffered BA.1," Luban said. BA.2 may derive its Greek name to distinguish it from Omicron. ,
Many people caught Omicron even after being infected with the delta variant, but it is unclear whether someone who caught Omicron remains susceptible to BA.2, said the head of the department of infectious diseases at Brigham and Women's Hospital. and a professor Dr. Daniel Kuritzkes said. at Harvard Medical School.
T cells, immune soldiers that appear to prevent serious disease after vaccination, will likely be effective against BA.2, said Dr. Bruce Walker, MD, director of the Ragan Institute at MIT and Harvard, which focuses on immunology research. .
"It is the T cells that probably have a major impact on the course of the disease once someone is infected," he said. "It's encouraging that - at least on the T cell side - they can't protect against being infected, but (vaccines) should help reduce disease."
Lemieux said it is not known when or where the first BA.2 emerged, although it appears to have separated from BA.1 several months earlier.
Although both types first appeared in southern Africa, it is unclear whether they originated there or simply came to public attention in an area that has provided extensive genetic sequencing during epidemics to track variations.
In order to spread, a newer version must be more permeable – or just lucky.
"We don't know what are the factors that are promoting the spread of BA.2, is it by chance, is it more intrinsically permeable, is it more permeable in terms of natural immunity against BA.1 - Those are the answers we'll begin to finish in the coming weeks," Lemieux said.
The reality, Lemieux said, is that while BA.2 is likely to spread in locations around the world for at least a few weeks, "we have an ability to combat the virus that is different by an order of magnitude from where we were two years ago." First."
"Yes, we have some tough decisions. We have some evidence to collect. We can't predict the future," Lemieux said, noting that vaccines and drugs like monoclonal antibodies and antivirals have seriously The risk of getting sick or dying has been reduced tenfold. COVID-19. "But I think we're in a tremendously optimistic place, despite all the transmission, despite all the challenges ahead."