“MRna vaccines are highly effective in preventing symptomatic and severe Covid disease associated with Sars-CoV-2 Delta variant infection.” Being vaccinated is “associated with a more rapid decline in viral load and a robust serological response.” It is a study conducted in Singapore, but not yet published and therefore not subjected to peer review, to confirm that “vaccination remains a key strategy for controlling the pandemic”.
The authors of the work – scientists from the National Center for Infectious Diseases in Singapore, Tan Tock Seng Hospital, Nanyang Technological University and the National University of Singapore – looked at data from 218 people who were admitted to hospital with Delta variant infection. , including 130 unvaccinated and 71 full course vaccinated (with an mRna vaccine). The retrospective multicenter cohort study shows that, “despite the significantly older age in the vaccinated group, the odds of severe Covid requiring oxygen support were significantly lower after vaccination”.
As for the viral load, it was initially “similar” between the vaccinated and unvaccinated groups at the time of diagnosis, “but decreased more rapidly in the vaccinated”. Also among the vaccinated patients a “strong early potentiation of antibodies to Spike protein was observed, however these antibody titers were significantly lower against the Delta variant” compared to the original strain of the wildtype virus.
This is “good news”, comments the virologist Guido Silvestri, a lecturer in the US at Emory University in Atlanta, who summarizes the results of the study on Facebook. For example, in fact, the “need for oxygen reduced by 87%, despite the higher average age (56 versus 39 years)”, among the vaccinated.
The expert also reflects on the data that shows that infections among vaccinated people are “characterized by a more rapid decline in viral load, which could help explain the surprising kinetics of the incidence curves in the UK, the Netherlands, etc.”, he concludes.