Three excellent studies, three answers: How much protection do omicron vaccines provide?
Three studies published yesterday offered more evidence that covid-19 vaccines are effective in protecting against the omicron variant, at least in those who received the third dose of the vaccine.
These are the first major US studies dealing with the protection provided by omicron vaccines, health officials said.
Studies have shown the results of previous studies, including studies in Germany, South Africa and the United Kingdom, which show that available vaccines are less effective against the omicron variant than previous coronavirus variants, but that the third dose significantly intensifies protection.
Hospitalization
The first study looked at hospitalizations and ambulance visits in 10 US states from August to January.
The efficacy of the vaccine has been found to be best after three doses of Pfizer or Moderna vaccine in the prevention of covid-19 emergency care.
Protection fell from 94 percent during the delta wave to 82 percent during the omicron wave.
Protection against only two doses was less, especially if six months had elapsed since the second dose.
Mortality
Another study focused on covid-19 cases and mortality rates in 25 US states from early April to Christmas.
People who received the third dose of the vaccine were more protected from coronavirus infection, both at a time when delta was predominant and at a time when omicron was predominant.
Both articles were published online by the Centers for Disease Control and Prevention (CDC). The Journal of the American Medical Association published the third study, which was also conducted by CDC researchers.
Overflowing coyote
They tested people who tested positive for covid-19 from December 10 to January 1 at more than 4.600 test sites across the United States.
Three doses of Pfizer and Modern vaccines were about 67 percent effective against omicron-related symptomatic diseases compared to unvaccinated people.
However, both doses did not provide significant protection against the omicron strain, the researchers found.