Johnson & Johnson single-dose vaccine loses the most efficiency over time

Efficiency vs. COVID-19 of vaccines Pfizer, Modern and Janssen from Johnson & Johnson (J&J) decreases over time. A study published by Science indicates that the protection of the three preparations against infection fell, on average, from 87.9% to 48.1% between February and October 2021, with the Janssen single-dose being the one that lost the most (to 13.1%) .

Research conducted with 780,000 people in the United States indicates that the greatest loss of efficiency was for Janssen, whose protection against infection went from 86.4% in March to 13.1% in September of this year.

The preparation that endured the most was Moderna with a decrease from 89.2% to 58%, while Pfizer-BioNTech went from 86.9% to 43.3%, between last February and October 1.

The study, according to its authors, is the first to compare the declining protection rates of the vaccines available to most Americans and to report on mortality rates after infection.

The research – signed by the Institute of Public Health, Veterans Affairs Medical Center and the University of Texas Health Sciences Center, all of them American – analyzed COVID-19 infection based on the vaccination of 780,225 veterans.

The study period coincides with the appearance and prevalence of the Delta variant in the United States and the progression patterns of the infection over time were consistent by age, despite vaccine eligibility, which implies that Delta is the main determinant of infection, experts add.

In addition, they emphasize that vaccination with any of the three preparations protected those infected against death.

The relative benefit of vaccines for protection against death was greatest for people under 65, but it was also “very strong” for those over that age.

The study showed that the risk of death from COVID-19 was higher in unvaccinated veterans, regardless of age and comorbidities.

By age, in the case of those under 65, the vaccines were, on average, 81.7% effective against death: Pfizer 84.3%, Moderna 81.5% and Janssen 73%, according to data from July to October .

Among people aged 65 and over, the overall efficacy against death was 71.6%. Modern 75.5%; Pfizer 70.1% and Janssen 52.2%.

This research offers “a solid basis for comparing the long-term efficacy of covid-19 vaccines and a lens for making informed decisions” about primary vaccination, booster doses, or measures such as mask use, depending on the lead study author, Barbara Cohn, from the American Institute of Public Health.