The omicron variant is making headlines as the world's newest strain of coronavirus. In the United States, where nearly 200,000 new coronavirus cases were reported Tuesday by Johns Hopkins University, top public health officials warn Americans to stay vigilant even as vaccination rates rise and travelers from countries where the variant was first detected are shut out.
Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, said during a news briefing on Tuesday that the delta variant accounts for 99% of positive cases sequenced in the United States. She and other members of the White House's COVID-19 response team asked the public for patience as researchers learn more about the omicron variant, which was first reported in South Africa on November 24.
In the U.S., 19 states have reported omicron infections, but that number is expected to rise as Americans continue to grapple with a pandemic that has persisted since the first COVID-19 case was identified in Washington state in January 2020.
"We must act together, in this moment, to address the impact of the current cases we are seeing, which are largely delta, and to prepare ourselves for the possibility of more omicron," Walensky said.
The jury is still out on several key questions related to the variant's transmissibility, severity and ability to evade immune responses, according to Anthony Fauci, the White House's chief medical adviser. But early data is encouraging, he said. Preliminary evidence from South Africa, where omicron has overtaken delta as the country's dominant variant, shows shorter hospital visits and reduced need for ventilators.
"It's too early to be able to determine the precise severity of disease, but … it appears that with the cases that are seen, we have not seen a very severe profile of disease," Fauci said. "In fact, it might be – and I underscore, might – be less severe."
Still, Fauci said many COVID-19 variants demonstrate increased transmissibility, underscoring the interconnectedness of a pandemic where hot spots often expand to engulf larger shares of the population. Omicron may be more transmissible than the delta variant, according to Fauci.
To help fight this, Jeff Zients, the administration's COVID-19 coordinator, said the U.S. has donated more than 300 million vaccine doses to 110 countries since Biden opened America's vaccine reserves in June. These efforts join a new program headed by the U.S. Agency for International Development to expand access and infrastructure in countries where vaccination rates lag. The program, called the Initiative for Global Vaccine Access, pledges $400 million to shore up poorer countries' vaccine manufacturing and delivery capabilities, especially in sub-Saharan Africa.
Southern African countries have been the subject of recent travel restrictions after researchers in South Africa first discovered the omicron variant. The Biden administration announced November 26 that travelers from eight African countries would be barred from the United States, and on Monday, the CDC began asking travelers passing through U.S. airports to submit proof of a negative COVID-19 test.
"There are lots of unknowns about the transmissibility, the severity, the vaccine impact of omicron," Zients said. "We understand that this limitation is causing difficulty for those in southern Africa, but we think a temporary limitation on a limited number of countries until we have the answers we need is a reasonable measure for a reasonable period of time."
Zients said the administration continues to make progress in vaccinating Americans: Last week, 12.5 million shots were administered, the highest weekly total since May. On Tuesday, 5 million children ages 5 to 11 received at least one dose – a "major milestone in our effort to keep our kids safe and our schools open," Zients said.
Nearly 61% of the U.S. population is fully vaccinated against COVID-19, according to Johns Hopkins University data. CDC data show climbing demand for vaccines as the omicron variant spreads and more age groups become eligible for the shot. Nearly 2.2 million vaccines were administered last Thursday, the highest single-day total in seven months. In the past week, nearly 7 million people received a booster, according to Zients.
Though research is still under way on how effective current vaccines are against the omicron variant, Walensky, Fauci and Zients encouraged Americans to stick with tried-and-true methods of limiting the spread of the coronavirus: testing, contact tracing, physical distancing and masks.
"At a time where there is much uncertainty with omicron, we find ourselves in a far better position now than we were last year," Walensky said. "We have gained knowledge and experience from addressing other variants, such as delta, and we have far more science, tools and treatment options available."