Public health authorities are keeping a close watch on the spread of the omicron subvariant BA.2, which is fueling an increase in COVID-19 cases in many parts of the world, and now accounts for more than half of all infections in the United States, according to the Centers for Disease Control and Prevention (CDC). That’s a dramatic jump from mid-March, when BA.2 made up less than a quarter of infections in the country.
In some U.S. regions, BA.2 numbers are significantly higher. In the Northeast, for example, more than 7 out of 10 cases are now due to the subvariant.
After weeks of seeing U.S. cases steadily decline, the CDC said that the seven-day average of new infections was slightly less than 60,000 cases per day — up 10 percent over the prior seven-day period.
Hospitalizations have also increased. The most recent seven-day average of 4,800 admissions per day due to COVID is up from 4,600 admissions per day in the prior seven-day period. Deaths, which typically lag behind cases and hospitalizations, have also started to rise, increasing nearly 3 percent to a seven-day average of approximately 1,000 deaths per day.
As The Boston Globe reported, government officials in Massachusetts recently recorded an uptick in both COVID-19 cases and coronavirus levels in wastewater in the eastern part of the state.
A Renewed Call to Take Precautionary Measures
In a March 29 press briefing, the director of the CDC, Rochelle Walensky, MD, MPH, told reporters that the trajectory of the pandemic in the United States now looks similar to that of many countries in Europe that have experienced a consistent and worrying spike in cases.
“For the health of our country, we must work together now to prevent a fourth surge,” said Dr. Walensky.
She warned that many states now are opening at levels she would not recommend. “I am working with the governors. I will be speaking with them to try and buckle down on trying to refrain from opening up too fast,” said Walensky.
In the same briefing, the White House’s chief medical adviser, Anthony Fauci, MD, added that states were relaxing protective measures prematurely.
“I think everyone really needs to appreciate that we really do want to get back to normal as quickly as we possibly can,” he said. “We’ve just got to hang in there a bit longer.”
A Worldwide Health Concern
Latest figures from the World Health Organization (WHO) show that BA.2 now makes up more than 85 percent of all infections worldwide and cases have been steadily rising over the past few weeks after consistently declining since the end of January. The upswing has been most dramatic in the Western Pacific (which includes China, Hong Kong, and South Korea), where the number of infections have been rising by as much as 20 percent every week.
The WHO’s Europe director, Hans Kluge, told reporters that COVID — largely driven by BA.2 — is on the rise in at least 18 out of 53 countries in the World Health Organization European region, according to France24. France, Britain, Ireland, Greece, and Cyprus have all been seeing case numbers climb.
Many of these nations have lifted restrictions, such as mask mandates for entering public places. Some public health officials believe leaders may have relaxed rules too extensively and too soon.
“Those countries are lifting the restrictions brutally from too much to too few,” Kluge said.
Vaccination Prevents Severe Illness
Research posted in January 2022 found that the BA.2 subvariant was substantially more transmissible than the original subvariant, omicron BA.1.
William Schaffner, MD, an infectious-disease specialist and a professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee, says the public has no need to be overly concerned — especially if they are vaccinated.
“You can think of BA.2 as ‘son of omicron,’” said Dr. Schaffner. “Its propensity to spread is certainly out there. It can produce mild infections, even in people who are vaccinated and boosted [called “breakthrough” infections], but it is unlikely to cause severe disease, and our current vaccines provide good protection against hospitalization. So in terms of the largest public health problem — severe disease — we’re in good shape.”
He added that if you’re older, have an underlying illness (such as diabetes, heart disease, lung disease), or if you’re immunocompromised — even though you’re vaccinated — you should especially continue to be cautious.
Walensky said that latest study data demonstrated that the risk of infection was reduced by 90 percent after individuals received the two recommended doses of either the Pfizer of Moderna vaccine.
A recent preprint study from the Lancet has raised some alarm, finding that BA.2 has the potential to cause more severe symptoms in children than other variants and the flu. Still, the researchers noted that serious outcomes and deaths were low.
Even if BA.2 tends to cause mostly mild symptoms, taking measures to prevent its spread could help suppress the development of new, potentially more dangerous mutations.
“If you have huge numbers of cases like we are seeing, the opportunity for even more variants is higher,” said Maria Van Kerkhove, the WHO’s COVID-19 technical lead, in a live Q&A session.
This content was originally published here.