By NANCY WEST, InDepthNH.org
CONCORD – The BA.2 Omicron variant of COVID-19 accounts for fewer than 10 percent of the infections in New Hampshire, according to state epidemiologist Dr. Ben Chan.
As of March 19, BA.2 is about 35 percent of circulating SARS-CoV-2 in the United States: https://covid.cdc.gov/covid-data-tracker/#variant-proportions, according to Dr. Michael Calderwood, an infectious disease and international health expert at Datmouth-Hichcock Medical Center.
In the Northeast, about 39 percent of infections are estimated to be due to the BA.2 variant, Chan said.
“However, fewer than 10 percent of infections in New Hampshire are currently due to the BA.2 variant, according to CDC data and genetic sequencing at the NH Public Health Laboratories,” Chan said in an email Monday.
The state Department of Health and Human Services announced three new deaths due to COVID-19 and three cases from more than two weeks ago that were only recently confirmed on Tuesday.
The state announced a continuing drop in hospitalizations down to 27 and 89 new cases of COVID-19.
At the same time that there has been an increasing proportion of BA.2 variant infections, New Hampshire and the U.S. have continued to experience a decline in the overall number of reported infections and a decline in hospitalizations, Chan said.
“All counties in New Hampshire are currently experiencing a ‘low’ level of COVID-19, according to the CDC’s new COVID-19 Community Level metrics.
“Additionally, preliminary data and studies show that the BA.2 variant is not more likely to evade vaccine or infection-induced immunity compared to the earlier Omicron variant (see recent NEJM article),” Chan said.
He explained that the Omicron variant is comprised of multiple different “subvariants,” including BA.1 and BA.2.
The fall and winter surge in New Hampshire and the U.S. was due to the rapid spread of the Omicron BA.1 variant, Chan said.
“In the last several weeks, the BA.2 variant has increased in the U.S. (see the CDC’s genomic surveillance data: https://covid.cdc.gov/covid-data-tracker/#variant-proportions).
“The increase in the BA.2 variant is likely due to increased infectiousness when compared to the original Omicron BA.1 variant,” Chan said.
Vaccinations, including booster doses, are expected to protect against the BA.2 variant and the Omicron variant, especially protecting against severe disease.
“Therefore, while we monitor for the emergence of the BA.2 and other variants, we continue to recommend everybody 5 years of age or older get vaccinated to protect themselves and their family from COVID-19, including the BA.2 variant, and ensure they are up-to-date and received all recommended vaccine doses,” Chan said.
Dr. Calderwood0 said in New England, BA.2 is at about 45 percent.
“So, it is already here, and it has been increasing for over a month,” Calderwood said. “Time will tell, but cases, hospitalizations, and deaths continue to decline.”
Calderwood said in the UK, more patients are testing positive for COVID-19 on hospital admission, but their cases requiring ICU level care are not increasing.
“This raises the possibility that these are patients coming in with COVID-19 but not from COVID-19.” https://coronavirus.data.gov.uk/details/healthcare
Calderwood said in the U.S., the CDC is tracking an increase in the Omicron BA.2 variant which appears to be 30 percent more transmissible but doesn’t appear to have more immune evasion than the original Omicron variant.
Some countries in Europe are seeing an increase again in COVID-19 cases related to the more transmissible BA.2 variant, with more people gathering indoors without masks, and waning immunity from vaccination (particularly among those who have not received a booster).
“Worth noting here is that ICU admissions don’t appear to be increasing. Dr. Fauci said this: ‘The issue with hospitalizations is a little bit more puzzling, because although the hospitalizations are going up, it is very clear that their use of ICU beds has not increased. So, are the numbers of hospitalizations a real reflection of COVID case, or is there a difficulty deciphering between people coming into the hospital with COVID or because of COVID?’” Calderwood said.
Calderwood said looking at mortality data specific to the Omicron wave in Europe, boosters continue to be very protective.
“This should continue to be a focus. Vaccination in the United States have now fallen to their lowest levels since they were initiated.
“We currently rank #67 in the world for completion of a primary series and #70 in the world for being up-to-date (including booster dose),” Calderwood said.
