Delta variant, the study: “Johnson & Johnson less effective”

Janssen’s Johnson & Johnson single-dose Covid vaccine may be much less effective against the Delta and Lambda variant of the SARS-CoV-2 coronavirus than the original strain. This is suggested by a new study, rebounded in the international media, according to which many of those who have received this shield product may have to consider a booster, a heterologous booster, ideally one of the mRna vaccines. The work, available online but not yet published in a scientific journal and therefore not yet peer-reviewed, comes to conflicting conclusions compared to other smaller studies published by J&J earlier this month, which instead suggest that a single dose of the vaccine is effective against the variant even eight months after inoculation. The study led by Nathaniel Landau, a virologist at the Grossman School of Medicine in New York, is based on experiments conducted with blood samples in the laboratory – reports the ‘New York Times’ – and may not reflect the performance of the vaccine in the real world, but its results, the experts note, are consistent with observations on a single dose of the AstraZeneca vaccine, which has a similar architecture and shows only about 33% efficacy against symptomatic disease caused by the Delta variant. ” we wanted to give – specifies Landau – it is not that people should not receive the J&J vaccine, but we hope that in the future it will be enhanced with another dose “of the same product” or with a “heterologous” booster with Pfizer or Moderna “. Other experts such as New York-based Weill Cornell Medicine virologist John Moore also think this should be considered a “two-dose vaccine.” If Moore therefore defines credible the results of the new study carried out by a team that has no ties to any of the vaccine manufacturers, Seema Kumar, spokesperson for J&J, highlights that the data from this work “do not speak of the full nature of immune protection “.