A team of English scientists has found that two doses of the Oxford-AstraZeneca or Pfizer-BioNTech COVID-19 vaccines are substantially less effective in protecting against the Omicron variant compared to previous variants of the coronavirus. In their new study (which has not yet been peer-reviewed), the Oxford University researchers analyzed blood samples from patients 28 days after their second dose of either vaccine.
When Ómicron was introduced into those samples, the scientists observed “a substantial drop” in neutralizing antibodies that fight COVID-19 compared to the immune responses observed against earlier variants. However, the report noted that after a booster dose, the vaccines were 70 to 75% effective in preventing symptomatic infections.
The study is cautious in pointing out that these findings do not indicate that two doses of either vaccine are ineffective in preventing serious illness, hospitalization, or death from COVID-19, but scientists hypothesize that an additional dose will significantly increase the responses of the vaccines. neutralizing antibodies.
Real-world effectiveness data has shown us that vaccines continue to protect against serious diseases compared to previous variants, so the best way to protect ourselves in the future in this pandemic is to get vaccinated , experts say.
The vaccine manufacturers said they would continue “at full speed” with their plans to develop an updated Omicron-based vaccine by March 2022 (if necessary).
Referencia: Wanwisa Dejnirattisai, Robert H Shaw, Piyada Supasa, Chang Liu, Arabella S V Stuart, Andrew J Pollard, Xinxue Liu, Teresa Lambe, Derrick Crook, Dave I Stuart, Juthathip Mongkolsapaya, Jonathan S Nguyen-Van-Tam, Matthew D Snape, Gavin R Screaton, Com-COV2 Study Group doi: https://doi.org/10.1101/2021.12.10.21267534
