By Lindsay Kalter
Dec. 15, 2021
Available booster shots against COVID-19 are enough to reduce serious disease caused by the highly transmissible Omicron variant, top infectious disease expert Anthony Fauci, MD, said Wednesday.
"Our booster vaccine regimens work against Omicron," he said at a White House news briefing. "At this point, there is no need for a variant-specific booster."
In the weeks since Omicron was first detected, scientists have been scrambling to collect data on its infection rates, how severe a disease it causes, and how well available vaccines work against it.
Fauci presented studies showing that boosters significantly reduce serious illness and hospitalization caused by Omicron.
In one study, the third dose of Pfizer's vaccine increased antibody levels against the variant by 25 times. Researchers from Rockefeller University in New York City found that people who had received boosters had 38 times the level of neutralizing COVID-19 activity.
A study from the U.K. Health Security Agency showed the booster is 75% effective against symptomatic disease.
"The Omicron variant undoubtedly compromises the effects of two-dose mRNA vaccine-induced antibodies and reduces the overall protection,” Fauci said. “However, considerable protection still maintains against severe disease.”
The variant has now been confirmed in 36 states and more than 75 countries.
CDC Director Rochelle Walensky, MD, said based on national genomic sequencing analyses, Omicron now makes up about 3% of COVID-19 cases in the United States. But in certain areas, including New York and New Jersey, that number is about 13%.
Omicron is more transmissible than the already highly infectious Delta variant, Walensky said, with a doubling time -- the time it takes for cases to double -- of about 2 days.
“In looking at early data on transmissibility of Omicron from other countries, we expect to see the proportion of Omicron cases here in the U.S. continue to grow in the coming weeks,” she said.
This week, the U.S. passed 50 million cases and 800,000 deaths from COVID-19.