This week America reached another grim milestone in the pandemic: 800,000 Americans have died from COVID-19, about 400,000 of them during the past year, when vaccines have been available.

And though the highest daily death tolls occurred almost 1 year ago, in January 2021, death counts have risen in recent weeks to an average of 1,100 fatalities per day, nearly triple the daily averages seen in June and July, before the Delta (B1617.2) variant became the dominant strain.

Omicron gaining foothold

According to Rochelle Walensky, MD, MPH, Centers for Disease Control and Prevention (CDC) director, Delta is still the dominant strain in the United States, but the new Omicron (B.1.1.529) variant is quickly gaining a foothold in parts of the country.

Today during a White House press briefing, Walensky said 3% of all national cases are caused by Omicron, but that percentage jumps to 13% in parts of New York and New Jersey. The strain has been detected in at least 36 states.

"We expect to see the proportion to grow in the coming weeks," said Walensky. "Early data suggest Omicron is more transmissible than Delta, with doubling time of 2 days."

But Anthony Fauci, MD, the top medical advisor to the White House, said booster doses were effective in raising protective antibody levels against Omicron.

"At this point there is no need for a variant-specific booster," Fauci said. Instead, all Americans who are eligible for primary vaccination and booster doses should get them as soon as possible.