A review of COVID vaccines: success against a moving target

Multiple vaccine platforms against COVID-19 have been developed and found safe and efficacious at a record speed. Although most are effective, they vary in their ease of production and distribution, their potential speed of modification against new variants, and their durability of protection and safety in certain target groups. Our discussion is based on published reports of clinical trials and analyses from national and global health agencies. The production of neutralizing antibodies against the viral spike protein is protective, and all vaccines for which published data exist have been found to be effective against severe disease caused by the viral strain they target. The degree to which vaccines protect against emerging variants, moderate disease and asymptomatic infection remains somewhat unclear. Knowledge of the duration of protection and its decay is increasing, and discussions of booster frequency and target strains are ongoing. The global effort to combat transmission and disease continues to rely upon intense epidemiological surveillance, whilst real-world data and clinical trials shape vaccination schedules and formulae.