This 2020 electron microscope image provided by the Centers for Disease Control and Prevention shows the SARS-CoV-2 virus particles that cause COVID-19. Hannah A. Bullock / Associated Press
The coronavirus mutant, which is now dominant in the United States, is a member of the omicron family, but scientists say it spreads faster than its omicron predecessors, cleverly escapes immunity and can cause more serious illness.
Why? Because it combines the properties of both the omicron and the delta, the nation’s dominant variant in the middle of last year.
A genetic trait that goes back to the pandemic’s past, known as the “delta mutation,” appears to allow the virus to “escape existing immunity from vaccination and previous infection, especially if you’ve been infected with the micron wave,” said Dr. Wesley Long. , pathologist at the Houston Methodist in Texas. This is because the original omicron strain that spread to the world did not have a mutation.
The “subvariant” of omicron, which is gaining popularity in the United States – known as BA.2.12.1 and responsible for 58% of COVID-19 cases in the United States last week – is not the only one affected by the delta mutation. Genetic change is also present in the relatives of omicron, which together dominate South Africa, known as BA.4 and BA.5. They have exactly the same mutation as the delta, while BA.2.12.1 has one that is almost identical.
This genetic change is bad news for people who have captured the original omicron and believe they are unlikely to get COVID-19 again soon. Although most people do not know for sure which variant caused their disease, the original Omicron caused a giant wave of cases late last year and early this year.
Long-standing laboratory data suggest that previous infection with the original omicron is not very protected against re-infection with new mutants, although the true risk of re-infection, regardless of the option, is unique to each person and situation.
Conversely, however, those who have previously contracted the delta may have additional armor to repel new mutants. A study published before being reviewed by other researchers at Ohio State University found that COVID patients in intensive care with delta infections induced antibodies that were better at neutralizing new mutants than patients who were caught the original omicron.
“The omicron infectious antibody does not appear to protect well from subvariants compared to delta,” said Dr. Shang-Lu Liu, author of the study, who co-runs the Ohio Virus and Emerging Pathogens Program.
But Liu said the level of protection provided by delta infection depends in part on how long someone has been ill. This is because immunity decreases over time.
People who have contracted the delta should not be considered invulnerable to the new sub-options, especially if they have not been vaccinated, Long said. “I wouldn’t say anyone is safe.”
A bright spot? Booster shots can provide strong protection against new mutants, Liu said. In general, vaccines and previous infections can protect people from the worst outcomes of COVID-19. At this point, scientists say it is too early to know whether the new mutant, which is needed in the United States, will cause a significant increase in new cases, hospitalizations and deaths.
Scientists are still trying to figure out how virulent these new mutants are. Long said he had not seen anything to answer that question about him, but Liu said reports showed a more serious illness. Liu said the subvariants have properties that suggest they spread more efficiently from cell to cell.
The virus “just hides in a cell and spreads through cell-to-cell contact,” Liu said. “It’s more scary because the virus doesn’t come out for the antibody to work.
Dr Eric Topol, head of the Translational Institute Scripps Research, said the new mutants certainly did not look less virulent than previous versions of omicron, and whether or not they were more virulent “would become clear in the coming months”.
Meanwhile, scientists expect the latest powerful mutants to spread quickly, as they are more portable than their predecessors.
Although home tests make it difficult to track all COVID cases in the United States, data from Johns Hopkins University show that the average is nearly 107,000 a day, up from about 87,000 two weeks ago. According to the Centers for Disease Control and Prevention, the number of new hospitals of patients with COVID-19 has been on an upward trend since mid-April.
“I hope we don’t see a similar increase in hospitalizations in previous waves,” Long said. “But with COVID, every time you have a lot of people who are infected, it’s just a numbers game. Some of these people will be tough. Some of these people will need to be hospitalized. Some of them, unfortunately, will pass. “
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