One British study suggests that the booster dose of the covid-19 vaccine loses its effectiveness in protecting against symptomatic infections caused by the Omicron variant after ten weeks.
There have not yet been serious enough cases of Omicron to evaluate the effectiveness of booster doses against severe symptomatic infection, but experts believe vaccines will continue to provide significant protection against hospitalization and death.
“It will take several weeks before the effectiveness of Omicron in treating serious diseases can be evaluated. However, based on previous experience, it is likely to be significantly higher than the estimates for symptomatic infections. ”, points to a new UK Health Safety Agency report cited The newspaper “New York Times…
In the weeks following the discovery of the Omicron variant, several studies showed that the mutation, first identified in South Africa, avoids the antibodies produced after vaccination or covid-19 infection.
However, a new UK report, which includes data on people vaccinated by immunizers AstraZeneca, Pfizer and Moderna, indicates that the vaccines – both the original vaccination schedule and booster doses – were less effective and reduced their protection against Omicron Variant faster than Variant Delta.
Among people who received both doses of AstraZeneca vaccine, a booster dose with one of the mRNA vaccines, Pfizer or Moderna, was 60% effective in preventing symptomatic infection two to four weeks after injection. However, ten weeks after injection, the Pfizer booster dose was only 35% effective. The booster dose of Moderna has been shown to be 45% effective within nine weeks of vaccination.
For people who received three doses of Pfizer Immunizer, efficacy dropped from 70% one week after taking the third dose to 45% after 10 weeks.
On the other hand, two doses of Pfizer and the Moderna booster were 75% effective until week nine.
This study was conducted by analyzing 148,000 cases of infection with the Delta variant and 68,000 with the Omicron variant, and also suggests that Omicron infections are usually less serious than Delta infections, but scientists believe these results should be interpreted with caution.
