Grading of recommendations, assessment, development, and evaluation (GRADE): Novavax COVID-19 vaccine

    Publication year: 2022

    A Grading of Recommendations, Assessment, Development and Evaluation (GRADE) review of the evidence for benefits and harms for Novavax coronavirus disease 2019 (COVID-19) vaccine was presented to the Advisory Committee on Immunization Practices (ACIP) on July 19, 2022. GRADE evidence type indicates the certainty in estimates from the available body of evidence. Evidence certainty ranges from type 1 (high certainty) to type 4 (very low certainty) [1]. The policy question was, “Should vaccination with Novavax COVID-19 vaccine be recommended for persons 18 years of age and older during an Emergency Use Authorization?” The potential benefits pre-specified by the ACIP COVID-19 Vaccines Work Group were prevention of symptomatic laboratory-confirmed COVID-19 (critical), hospitalization due to COVID-19 (critical), death due to COVID-19 (important), and asymptomatic SARS-CoV-2 infection (important). The two pre-specified harms were serious adverse events (critical) and reactogenicity grade ≥3 (important). A systematic review of evidence on the efficacy and safety of a two-dose regimen of Novavax COVID-19 vaccine among persons aged 18 years and older was conducted. The quality of evidence from one Phase III randomized controlled trial was assessed using a modified GRADE approach [2-3]. A lower risk of symptomatic COVID-19 was observed with vaccination compared to placebo (relative risk [RR] 0.10, 95% confidence interval [CI]: 0.06, 0.18, evidence type 1), corresponding to a vaccine efficacy of 89.6% (95% CI: 82.4%, 93.8%). This was observed with a median follow-up of 2.5 months, during a period of Alpha variant predominance. The vaccine was also associated with a lower risk of severe illness due to COVID-19 (RR 0.00; 95% CI: 0.00, 1.00; evidence type 3), corresponding to a vaccine efficacy of 100% (95% CI: 0%, 100%). The measure of severe COVID-19 was used as surrogate for the GRADE outcome of hospitalization due to COVID-19. No hospitalizations or deaths due to COVID-19 were identified among vaccine recipients or placebo recipients in the per-protocol population.* In terms of harms, the available data indicated that serious adverse events were balanced between the vaccine and placebo arms (RR 0.92; 95% CI: 0.73, 1.16; evidence type 1). Reactogenicity grade ≥3 was associated with vaccination (RR 4.11; 95% CI: 3.70, 4.57; evidence type 1), 16.3% of vaccine recipients and 4% of placebo recipients reported any grade ≥3 local or systemic reactions following either dose 1 or dose 2.