Pfizer vaccine protects against 70% of severe Omicron cases, study finds
The vaccine of the American laboratory Pfizer is globally less effective against Omicron but protects at 70% against severe cases, according to a study presented Tuesday and carried out in South Africa, which detected the new variant in November.
There are many uncertainties about the nature of this new form of Covid-19. Scientists’ initial observations suggest that it is more contagious, but the unusually high number of mutations it contains raises many concerns about its ability to resist vaccines.
The study, developed by the country’s leading private health insurance company, Discovery, with scientists from the South African Medical Research Council (SAMRC), is based on the results of 78,000 PCR tests obtained between November 15 and December 7.
“The double-dose Pfizer vaccine shows 70% effectiveness in reducing hospitalizations,” Discovery President Ryan Noach said in an online press conference. The vaccine was previously 93% effective against severe cases.
Overall, “vaccine efficacy is significantly reduced with a high number of brief infections in vaccinated individuals,” he continued. The study shows a 33% efficacy against the risk of infection, with a high number of reinfections, compared to 80% against the previous dominant Delta variant.
Glenda Gray, president of SAMRC, a public medical research organization, called the results “extremely encouraging,” noting that “the vaccine is designed to protect against hospitalization and death.
“Despite less severe cases, health systems could be overwhelmed by the volume of infections, given the rapid spread of Omicron,” Noach warned.