A new study out of South Africa shows that Pfizer’s two-dose COVID-19 vaccine provides a high degree of protection against hospitalization from the fast-spreading omicron variant.
The real-world study, conducted by the South African Medical Research Council and Discovery Health, the country’s largest private health insurance administrator, was based on more than 211,000 positive COVID-19 test results between November 15 to December 7, with about 78,000 believed to be caused by omicron.
The study concluded that while the vaccine offered only a 33% rate of protection against an overall infection, it provided 70% protection against hospitalization. It also concludes that while there was a higher risk of reinfection during this current surge, the risk of hospitalization among adults was 29% lower than during the initial wave. Pfizer developed the vaccine in collaboration with German-based BioNTech.
South Africa is experiencing a dramatic surge in new daily COVID-19 cases driven by omicron, which was first announced by the country in November.
In a related development, Pfizer announced Tuesday that a new study of its experimental COVID-19 antiviral pill confirms it is highly effective in preventing severe disease among high-risk adults that could lead to hospitalizations and deaths, even against the omicron variant.
The company says it found that the drug, dubbed Paxlovid, reduced the risk of hospitalization and death by 89% if given within three days of the onset of COVID-19 symptoms, and as much 88% if administered within five days.
Pfizer has asked the U.S. Food and Drug Administration to authorize use of Paxlovid based on results from a preliminary study.
The FDA is expected to announce soon whether to grant permission for doctors to use Paxlovid and a competing drug, molnupiravir, developed by Merck. Merck said last month a clinical trial revealed molnupiravir reduced hospitalizations and deaths by only 30% among high-risk adults.
The new developments come as health authorities around the world are warning that omicron could soon surpass delta as the most dominant variant of the coronavirus.
Denmark says omicron will trigger 10,000 new infections by the end of the week, compared to the current rate of 6,000 cases driven entirely by delta. The Norwegian Institute of Public Health also warned Monday that omicron “will soon dominate,” with new infections rising from 4,700 daily cases to a record 90,000 to 300,000 daily cases.
The new warnings come just days after the World Health Organization warned that omicron poses a “very high” global risk because its mutations may lead to higher transmission. The U.N. health agency said while the current vaccines are less effective against omicron, early data shows it causes less severe symptoms than other variants.
Meanwhile, China is reporting its second case of omicron infection on its mainland. A 67-year-old man tested positive Monday, two weeks after arriving in Shanghai from overseas. Authorities say the man repeatedly tested negative during his mandatory two-week hotel quarantine before flying to the southern city of Guangzhou, where he was spending another week in self-isolation at his residence. He tested positive for the new variant after researchers conducted genome sequencing.
The first case of omicron on mainland China was a person in the northern port city of Tianjin who tested positive for the new variant after arriving from overseas on December 9. The individual, who was shown to be asymptomatic, is now quarantined and undergoing treatment in a hospital.
The first cases of omicron on mainland China come two years after COVID-19, the disease caused by the coronavirus, was first detected in the central city of Wuhan. China has since imposed a “zero-tolerance” strategy, including mass testing, snap lockdowns and extensive quarantines, as a means to prevent any further outbreaks.
Some information for this report came from the Associated Press and Reuters.