Booster vaccines lose efficacy against omicron, according to a British study

A clinical model suggests that the efficacy of booster vaccines against COVID-19 caused by omicron is lower than that of the delta variant, although they still offer high protection against the disease, according to researchers from Imperial College London (United Kingdom).

The researchers also analyzed the risk of reinfection with omicron in another study and found that it is 5.4 times higher than with delta, which suggests that the protection offered by a previous infection against the new variant could be less than 19%.

Regarding additional punctures, the aforementioned clinical model estimates that after two doses and the booster dose there is a 4.5-fold reduction in the levels of neutralizing antibodies against omicron compared to delta.

For this work, they analyzed three scenarios and, in the worst case, they assumed that the efficacy of the vaccines declines at the same rate after the booster shot as after the two doses.

In this context, they detected that the effectiveness of the preparations to avoid hospitalizations two months after administering the reinforcement can fall from the 96.85% offered by delta to 80.1% for omicron.

The researchers indicate that these percentages translate into a “high degree of individual protection“But warn that the new variant is likely to cause large numbers of infections and” may seriously affect the capacity of health systems around the world.

“While the degree of decline (of efficacy) against severe disease, which requires hospitalization, is less than against mild disease, even small reductions in protection can cause significant increases in hospital admissions and deaths, especially in groups of high risk ”, they observe in a statement.

They also specify that, although these results are still surrounded by uncertainty, given the recent appearance of omicron, they suggest that it will be necessary to develop specific vaccines for this variant and / or booster doses for “restore protection”.

However, they emphasize that there are now “more evidence“On how omicron can”very substantially evade ” the “Immunity granted by both previous infections and vaccines”.

“This level of immune evasion means that omicron poses a significant and imminent threat to public health.”, Emphasizes the expert Neil Ferguson, of the Imperial College.

His colleague Azra Ghani adds that the ability to “quantify“The risk of reinfection and the efficacy of the preparations against omicron is”essential“To make projections about your”future path” e “impact”In immunization campaigns.