NVX-CoV2373 COVID-19 Vaccine Safe and Effective for Adolescents

Results of a study published in JAMA Network Open indicate that the NVX-CoV2373 COVID-19 vaccine is safe, immunogenic, and effective among adolescents.

This ongoing randomized clinical trial comprising adolescents (age, 12-17 years) in Mexico and the United States is an expansion of PREVENT-19, a phase 3, randomized, observer-blinded, placebo-controlled multicenter study. Researchers enrolled participants from April to June 2021. Participants were randomly assigned 2:1 to receive 2 intramuscular injections of either NVX-CoV2373 (n=1,487) or placebo (n=745), administered 3 weeks apart.

Outcomes assessed included serologic noninferiority of neutralizing antibody responses among the study population compared with those previously observed in younger adults; protective efficacy against COVID-19 infection; and reactogenicity and safety.

Among 2,232 participants included in the safety analysis, the mean (SD) age was 13.8 (1.4) years, 1,172 (52.5%) were of male sex, 1,660 (74.4%) were White, and 359 (16.1%) were previously infected with COVID-19.

Solicited local and systemic adverse events (AEs) were more commonly observed after receipt of the second injection and more frequent among patients in the NVX-CoV2373 vs placebo groups. The most commonly reported local AEs included injection site pain and tenderness, with most being of mild to moderate severity and self-limiting (median duration, ≤2 days). Of reported systemic AEs, the most common were headache, fatigue, myalgia, and malaise.

The per-protocol efficacy population included 1799, none of whom had prior exposure COVID-19. Among these patients, the incidence of COVID-19 infection per 100 person-years was higher among those in the placebo group (14.20; 95% CI, 8.42-23.93) compared with those in the NVX-CoV2373 group (2.90; 95% CI, 1.31-6.46). Further analysis showed that the efficacy of the NVX-CoV2373 vaccine against COVID-19 infection was 79.5% (95% CI, 46.8-92.1). However, the efficacy of the vaccine against moderate to severe infection could not be determined as all reported COVID-19 diagnoses were of mild severity.

Between baseline and day 35 after NVX-CoV2373 receipt, the percentage of adolescents with a 4-fold and higher increase in neutralizing antibodies was noninferior to that observed among younger adults (Difference, -1.0; 95% CI, -2.8 to -0.2).

Limitations of this study include its short duration (median surveillance time, 64 days). Other limitations include the low number of COVID-19 diagnoses and insufficient ability to determine the efficacy of NVX-CoV2373 against a greater number of COVID-19 variants.

“NVX-CoV2373 offers an important choice for vaccination of younger individuals in the fight against the current COVID-19 pandemic worldwide,” the researchers concluded.

This article originally appeared on Infectious Disease Advisor