First studies into vaccine efficacy against Omicron spark cautious optimism

While the new variant did lower vaccine efficacy, the loss was not complete.

A study in South Africa among 14 persons given who were administered two doses of the Pfizer-BioNTech shot revealed a 41-fold reduction in the level of virus-blocking antibodies that it generated, when compared to its efficacy against the strain of SARS-CoV-2 that was dominant when the pandemic began.

According to the lead investigator of the first study, Alex Sigal, the head of research at the Africa Health Research Institute in Durban, a "good" booster was likely to reduce people´s chance of becoming infected, particularly the odds of becoming severely ill.

Furthermore, a second study conducted at Sweden's Karolinska Institute was more optimistic, showing that the fall in antibody count was only slightly greater than in the case of Delta, while a German study yielded a 37-fold reduction in the number of antibodies that were generated.

Sigal reportedly recommended that fully vaccinated individuals receive a booster and that those previously infected should get a shot.

The study conducted by Sigal also revealed that the level of neutralising antibodies among the volunteers who had been vaccinated and who had also suffered a previous bout of Covid-19 were significantly higher, providing reasonable protection against Omicron.