Vaccines: 10 to 30% less effective against Delta variant

The LNS confirms a slight loss of vaccine effectiveness against the Delta variant. It still recommends vaccination. (Photo: Nader Ghavami/Maison Moderne)

The LNS confirms a slight loss of vaccine effectiveness against the Delta variant. It still recommends vaccination. (Photo: Nader Ghavami/Maison Moderne)

The LNS reports a 10 to 30% reduction in the efficacy of the anti-covid vaccine against the Delta variant, but the jab still offers protection against severe forms of the disease.

The Delta variant now accounts for all of the covid-19 cases studied by the National Health Laboratory (LNS). But why is it considered to be of "concern"?

First, because its transmissibility is "increased", the laboratory writes in a scientific note, compared to the Alpha variant (formerly called the "British" variant and classified as a concern) or other variants (of lesser concern). "Delta cases infect more people on average. This is partly due to a higher viral load and a shorter incubation period." The variant, scientifically named B.1.617.2 and first discovered in India, has more serious health consequences. "A higher risk of hospitalisation was observed in Delta cases, showing a directly proportional relationship with age." It does not appear to have an impact on the diagnosis of positive cases.

Protection from vaccination remains high

The question remains: does the Covid-19 vaccine protect against the Delta variant? The LNS is cautious and points out that "the evidence in this regard is still limited". But it notes a "reduction in neutralising immunity by 10-30%" in both vaccinated and previously infected persons. "Vaccinated people retain high levels of protection against severe disease," the laboratory states.

The LNS also concludes that despite this impact on immunity, "the protection conferred by vaccination remains high". It encourages vaccination and the maintenance of public health measures, such as "wearing a mask in indoor public places".

This article was originally published in French on Paperjam.lu. It has been translated and edited for Delano.lu