Can a combination of vaccination and face mask wearing contain the COVID-19 pandemic?

The COVID-19 pandemic is going into its third year with Europe again being the focus of major epidemic activity. The present review tries to answer the question whether one can come to grip with the pandemic by a combination of vaccinations and non-pharmaceutical interventions (NPIs). Several COVID-19 vaccines are of remarkable efficacy and achieve high protection rates against symptomatic disease, especially severe disease, but mathematical models suggest that the current vaccination coverage in many countries is insufficient to achieve pandemic control. NPIs are needed as complementary measures because recent research has also revealed the limits of vaccination alone. Here, we review the evidence for efficacy of face mask wearing in various settings. Overall pooled analysis showed significant reduction in COVID-19 incidence with mask wearing, although heterogeneity between studies was substantial. Controlled trials of mask wearing are difficult to conduct, separating mask wearing effects in population studies from the impact of other NPIs is challenging and the efficacy of masks depend on mask material and mask fit. The combination of vaccination and mask wearing is potentially synergistic since vaccination protects so far well from disease development (the omicron variant is currently an unknown) but immunity from infection wanes over few months after vaccination. In comparison, masks interfere with the virus transmission process at a level of a physical barrier independent of coronavirus variant. Vaccination and masks are much less costly to apply than other NPI measures which are associated with high economic and social costs, but paradoxically both measures are the target of a vocal opposition by a sizable minority of the society. In parallel with biomedical research, we need more social science research into this opposition to guide political decisions on how to end the pandemic.