COVID-19-Impfungen: Replizierend oder Nichtreplizierend? Der Vektor in Sputnik-V

Abstract

Innovative and effective vaccination strategies are the most important lever to address the global SARS-COV2 pandemic. Within months scientists all over the world have developed promising new vaccines, many of which use adenoviral vectors to incorporate immunogenic molecules of SARS-coronavirus in order to elicit effective immune responses. The Gamaleya institute developed the COVID-19 vaccine named Sputnik (Gam-COVID-Vac) using adenoviral vectors ad 26 and ad5 to incorporate a full SARS-Spike Protein for vaccination. Two differing vectors enable so called prime-boost, thus avoiding neutralizing effects against the vector itself, ensuring proper immunogenicity against the vaccine. Current available published evidence has raised controversy among small sample sizes in phase II and early endpoints in phase III studies with Sputnik and scientific community took notice that full study protocols and clinical data haven't been made available yet. Patient subgroups and vaccination efficacy in healthy vaccinated may be at risk in case of partial viral replication of Ad5 vectors or when batch to batch reproducibility is not warranted, as concerns from authorities in Brazil and Slovakia have recently been raised. Final approval by governing health authorities (e. g. EMA) should therefore be awaited.