Why This ‘Very, Very Contagious’ Coronavirus Subvariant Is Causing Cases To Rise Again
After a weeks-long plateau, coronavirus cases and hospitalizations are once again rising in the U.S. as a new, highly transmissible omicron subvariant rapidly makes its way toward becoming the next dominant virus strain.
The current seven-day rolling average of cases is back to where it was in February, with an average of 64,000 cases tallied Monday by the Centers for Disease Control and Prevention. That’s roughly three times what it was toward the end of March.
The seven-day average for hospitalizations is also up by 20%, with the CDC reporting an average of 2,215 admissions over the last seven days ― up from the prior week’s average of 1,845.
Deaths from COVID-19 have stayed near record lows.
This drop in fatalities is likely thanks in part to current dominant variants appearing to be less deadly and vaccination rates being high in the U.S., Dr. Robert Garry, a professor of microbiology and immunology at Tulane University, told HuffPost. As of this week, roughly 66% of the U.S. population has been fully vaccinated, according to the CDC.
“The preexisting immunity lets your body handle the infection better, but these variants are so infectious they may not keep you from getting infected,” he said.
While the dominant omicron subvariant BA.2, which currently makes up nearly 62% of cases, appears to spread more easily than its predecessor, experts say another subvariant, BA.2.12.1, appears to be even more transmissible. BA.2.12.1 is spreading about 24% faster than BA.2 and, based on current rates, could become the dominant variant within the next few weeks, data shows.
This increased transmissibility may be because BA.2.12.1 has not only the omicron BA.2 variant mutation but two more mutations, said Garry.
“One of these makes the virus replicate a bit better (S704L). The other (L452Q) makes it resist prior immunity,” he said of these two additional spike protein mutations.
“So BA.2.12.1 is more infectious. None of the omicron subvariants seem to induce more severe disease than the original omicron (BA.1). BA.1 seems less severe than delta, but, again, the role of preexisting immunity is hard to factor in,” he added.
“We have a very, very contagious variant out there. It is going to be hard to ensure that no one gets COVID in America,” Dr. Ashish Jha, White House COVID-19 response coordinator, said last week following news of a positive coronavirus test for Vice President Kamala Harris, who is fully vaccinated and twice boosted.
Health officials have cautioned that while these current subvariants may be less severe, they could lead to long-term health issues.
“I think people sometimes say, well, it’s OK to get infected. No, it’s not, because there are things like long COVID, and there are sometimes people, even though they don’t require hospitalization … they get significantly ill,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told ABC’s “This Week” last month. “That’s not something to pooh-pooh.”
Elsewhere in the world, health officials are monitoring the spread of two less common subvariants of omicron: BA.4 and BA.5.
South African scientists have said these subvariants, which have been blamed for a recent spike in cases in the country, are capable of dodging antibodies acquired from prior COVID-19 infection, though not the antibodies acquired from vaccination.
“It’s too soon to know whether these new subvariants can cause more severe disease than other omicron subvariants, but early data suggest vaccination remains protective against severe disease and death,” Dr. Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, said at a press conference Wednesday.