A two-shot course of mRNA vaccines or the one-shot J&J vaccine seem to be less effective against the Omicron variant, especially for infection.
Data so far indicates that mRNA vaccines (Pfizer-BioNTech or Moderna) offer the most promising protection against both infection and hospitalization, in line with the CDC’s recommendations.
Current figures suggest that vaccines offer 30 to 40 percent protection against infection and around 70 percent protection against hospitalization without boosters.
Newer data is confirming that a third dose increases antibody production and boosts effectiveness against infection to around 75 percent and 85 percent for severe disease. This is a developing story. We’ll update it as we learn more.
Omicron is spreading rapidly across the globe, and researchers are racing to understand how vaccines will hold up against this new variant of the coro-navirus.
Several preliminary studies have assessed the effectiveness of current COVID-19 vaccines in use against the Omicron variant. So far, one- or two-dose vaccines provide far less protection than those paired with a booster, but they still do appear to protect against severe disease.
Studies conducted in the lab and the real world show that full vaccination plus a booster shot provides stronger protection against infection with Omicron.
It is important to remember most of these are lab studies and may not reflect the vaccines’ real-world performance.
Early estimates suggest that vaccine effectiveness against symptomatic infection with Omicron is sig-nificantly lower compared with the Delta variant.
A report by Imperial College London indicated that the risk of reinfection with Omicron was 5.4 times greater than the Delta variant. Previously having COVID-19 also afforded little protection against reinfection with Omicron.
“This is such a contagious virus that it can spread not only among the unvaccinated, where I think it still has a very sub-stantial risk of causing serious disease that might require hospitalization, but it can also spread among vaccinated persons, although the illness it produces among the vaccinated, particularly if you’ve had a boost, is generally mild and even without symp-toms,” said Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Van-derbilt University Medical Center in Tennessee.
