1 of 4 | A man receives a vaccination against COVID-19 at a government-run clinic in Johannesburg, South Africa, on December 3. Photo by Kim Ludbrook/EPA-EFE
The Omicron variant was first detected in South Africa.
"The Omicron-driven fourth [wave] has a significantly steeper trajectory of new infections relative to prior waves," Discovery Health CEO Dr. Ryan Noach said, according to USA Today.
"National data show an exponential increase in both new infections and test positivity rates during the first three weeks of this wave, indicating a highly transmissible variant with rapid community spread of infection."
Although the Pfizer vaccine appears to be weaker against Omicron, it still offers about 70% protection against severe COVID-19, the study said. File Photo by Debbie Hill/UPI
The study also indicates that the Omicron variant is more resistant to the vaccine produced by Pfizer and BioNTech.
According to the research, full vaccination with Pfizer's two doses provided just 33% protection against infection from Omicron and 70% protection against hospitalization, compared to those who are not vaccinated.
"Seventy percent is definitely a drop down," said Dr. Eric Topol, vice president for research at Scripps Research in La Jolla, Calif., according to USA Today. "It isn't great. It was 95% effective severe disease when it was Delta variant and then about 85% after six months of waning."
The study is based on more than 200,000 positive COVID-19 tests between mid-November and early December. About 78,000 were attributed to Omicron, but are not confirmed to have been caused by the new variant.
Health officials say Omicron comprises about 90% of all cases in South Africa and spreads in a similar pattern as the Delta. Omicron has spread to most countries around the world and caused its first confirmed death this week, in Britain.