Israel’s ministry of health said Wednesday it had recorded two cases of new COVID variant, but which officials said they were not unduly worried about.
To ensure COVID-19 vaccines provide optimal protection into the future, the World Health Organization says the formulas may need to be updated as new, antigenically distinct variants emerge. The updated vaccines may be monovalent targeting the predominant circulating variant, or multivalent based on different variants.
Ideally, COVID-19 vaccines will prevent infection and transmission, in addition to providing protection against severe disease and death. The development of pan coronavirus vaccines, as well as the development of vaccines that are able to elicit mucosal immunity, may be desirable options, but the timeframe for their development and production is uncertain.
The BA.2 sub-lineage of the Omicron variant now makes up nearly a quarter of new COVID-19 infections nationwide in the United States, the Centers for Disease Control and Prevention estimated Tuesday, up from around 1 in 10 new cases just a week prior.
Since January, Omicron has made up virtually all new infections in the U.S. Like in many countries abroad, most cases in the U.S. had been caused by a sub-lineage of Omicron known as BA.1. But while both BA.1 and BA.2 can be traced back to some of the earliest samples gathered of Omicron, BA.2 has only recently begun to climb in prevalence.
The strain, combining two sub-variants of the Omicron version of the COVID-19 virus—dubbed BA.1 and BA.2—was recorded during PCR tests on two passengers arriving at Israel’s Ben Gurion airport.
“This variant is still unknown around the world,” the ministry statement read.
“The two cases of the combined strain, which have been discovered so far, suffered from mild symptoms of fever, headaches and muscle dystrophy, and do not require a special medical response,” it added.
Israel’s pandemic response chief, Salman Zarka, played down the risks.
“The phenomenon of combined variants is well known,” Zarka told Army Radio. “At this stage, we are not worried about it leading to serious cases”.
More than four million people out of Israel’s population of 9.2 million have received three coronavirus vaccine shots.
A total of almost 1.4 million cases of COVID infection, including 8,244 deaths, have been officially recorded in the country.
Last month, Israel announced that unvaccinated tourists would be allowed to enter as part of an easing of COVID restrictions.
The country was seeing a “consistent decline in morbidity data,” Prime Minister Naftali Bennett said.
A previous effort to reopen the border last November foundered after just a few weeks because of the fast-spreading Omicron variant.
Israel was one of the first countries to launch a national vaccination campaign in December 2020.
Earlier this month, the government announced it would provide fourth COVID vaccine shots to people over 60 and health workers, amid a surge driven by the Omicron variant.
The Omicron subvariant BA.2 now accounts for almost one-quarter of new COVID-19 infections across the United States, according to estimates released this week by the U.S. Centers for Disease Control and Prevention.
For the week ending March 12, BA.2 made up 23.1% of new cases, the CDC said in its “Nowcast” estimates. That’s up from 13.7% of new cases for the week ending March 5, 7.1% for the week ending Feb. 26, and 4.1% for the week ending Feb. 19.
BA.2 accounts for 39% of cases in New York and New Jersey and about the same amount in New England, CBS News said. The CDC map shows BA.2 accounting for 12.4% of new cases in the Southeast and 26.2% in the Northwest.
The CDC says it will be updating its Nowcast estimates each Tuesday.
“The median time from specimen collection to sequence data reporting is about 3 weeks,” the agency said. “As a result, weighted estimates for the most recent few weeks may be unstable or unavailable. CDC’s Nowcast is a data projection tool that helps fill this gap by generating timely estimates of variant proportions for variants that are circulating in the United States.”
BA.2 is dominating the number of infections in many nations, especially in European nations that are reporting COVID surges even as governments lift many COVID safety restrictions. The United Kingdom recently said BA.2 makes up the majority of cases there. China, which had successfully tamped down COVID surges, is also grappling with a spike in BA.2 cases.
Even as BA.2 makes up a greater proportion of U.S. COVID cases, overall COVID cases and hospitalizations continue to drop in many states.
“Although the proportion of infections with BA.2 is increasing in the U.S., COVID-19 cases are now declining, so it is likely that absolute numbers of BA.2 infections are not increasing as quickly as they might seem from just looking at the proportion that are BA.2,” Deborah Dowell, MD, the CDC’s chief medical officer for the agency’s COVID-19 response, said over the weekend, according to CBS News.
She noted that BA.2 apparently is not taking root in the United States as quickly as in other places.
“The speculation I’ve seen is that it may extend the curve going down of case rates of Omicron but is unlikely to cause another surge the way we’ve seen that we saw initially with Omicron,” Dowell said.
The increase in BA.2’s proportion in the U.S. comes as the CDC has continued to track a nationwide slowdown in the pace of new COVID-19 hospitalizations and cases.
Those trends appear to hold true even in the regions with the highest share of BA.2 cases, though early-warning data gathered by the agency from wastewater samples does suggest some communities might soon see an uptick.