Pfizer’s COVID-19 Vaccine Highly Effective in Adolescents

The vaccine COVID-19 Pfizer-BioNTech is highly effective in teenagers, according to a study focused on delta variant SARS-CoV-2 and showing that in fully vaccinated youth the risk of symptomatic disease decreased 93% compared to unvaccinated.

The work is published in the magazine “The New England Journal of Medicine” with data on the adolescent population of Israel, and its manager is the Israeli Clalit Research Institute, in collaboration with Harvard University (United States).

The analysis provides the largest published assessment of the effectiveness of a COVID-19 vaccine among adolescents, in a nationwide mass vaccination setting, and marks the first study of its kind in which the delta variant was dominant, it says. a statement from the Clalit research center.

The study took place between June 8 and September 14, coinciding with the fourth wave, during which the delta variant was dominant for new infections in the country.

The researchers reviewed data from 94,354 vaccinated teens ages 12 to 18.

These were carefully matched, the authors explain, with 94,354 unvaccinated adolescents based on a broad set of demographic, geographic and health characteristics associated with risk of infection, risk of serious illness, or health status.

The results show that in fully vaccinated adolescents (between 7 and 21 days after the second dose), the risk of symptomatic COVID-19 decreased 93% compared to the unvaccinated, while the risk of documented infection decreased 90%.

In the period immediately before the second dose (days 14-20 after the first dose), the effectiveness of the vaccine was lower, but still substantial: the risk of symptomatic COVID-19 decreased 57% in vaccinated individuals, and the risk of documented infection 59%.

There were insufficient data to provide an estimate on the reduction in the incidence of severe disease, hospitalization and mortality, as these results are rare among adolescents, the center note states.

Study lead author and Clalit director Ran Balicer notes that these results convincingly show that, one week after the second dose, this vaccine is highly effective against symptomatic COVID-19 and against all documented infections in adolescents. .

“These data should facilitate informed individual decision-making about the risk-benefit ratio and, in our opinion, constitute a strong argument in favor of the option to be vaccinated, especially in countries where the virus is currently widespread,” he adds. .

For Ben Reis, from Boston Children’s Hospital and Harvard Medical School, “to date, one of the main factors of indecision in vaccination has been the lack of information on the effectiveness of the vaccine.”

“This careful epidemiological study provides reliable information, which we hope will be useful for those who have not yet decided on vaccination,” he said.