Ómicron: What Studies Say About The Effi0cacy Of Vaccines Against The New Variant


Whether the vaccines we have work or not -and to what extent- against omicron is something that we will learn in more detail as the days go by. This is how science works. It evolves as events occur and evidence accumulates.

This new variant of coronavirus appears to have a greater ability to escape immunization, but the available research indicates that our vaccines will continue to protect against the most serious forms of the disease.

Of course, this will continue to depend on many factors. A young and healthy person does not react the same as an elderly person or with some other risk factor, for example.

How does the Pfizer vaccine protect?

This Wednesday, Pfizer and BioNTech, creators of one of the most administered vaccines in the world, presented the first preliminary reports on the protection against omicron.

Once again, these are data that must be interpreted as the first available evidence. Neither their findings are definitive nor do we have enough information from other manufacturers such as AstraZeneca, Moderna, Sinopharm, Sinovac, or Sputnik V, to name other vaccines that are being administered in Latin America, for example.

Omicron variant chart

Pfizer analysis indicated that the protective effect falls dramatically against the new variant. However, they added that a booster dose greatly increases the immune system’s defense against omicron.

Several countries, especially those with more resources, have begun to administer the third dose to their population, which has generated ethical debates about whether it is a higher priority to further strengthen the protection of citizens of rich countries or to ensure that the most lagging countries have access to more vaccines.

According to a Pfizer statement, plasma from people who received two doses of the current covid vaccine had an average 25-fold reduction in omicron neutralization compared to previous versions of the virus.

The good news is that the Pfizer booster dose appears to offer such protection.

Booster dose

Another preliminary study, not peer-reviewed and sponsored by vaccine manufacturers, specifically evaluated the effectiveness of booster doses (in this case, those from Pfizer and Janssen) in 65 individuals.

Although not omicron specific, the study suggests that the additional dose of the vaccine ” increases antibody responses in people who had been vaccinated at least six months previously” with the Pfizer vaccine.

Healthcare staff member holding a dose of Pfizer.

However, the researchers note that it is still unknown how long this protection boost will last.

For now, the World Health Organization (WHO) maintains that the expectation is that the vaccines will continue to be effective against omicron.

“We have highly efficient vaccines, which are effective against all variants so far, in terms of preventing severe forms of covid-19 and hospitalizations. There is no reason to believe that it will be any different ” omicron, Mike Ryan told the AFP agency, WHO emergency director.