Vaccination against coronavirus disease 2019 (COVID-19)

The clinical presentation of infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is very heterogeneous and the risk of a severe course clearly increases with age. Therefore, older adults are an important target group for vaccinations. Several vaccines are currently licensed in Europe for older adults, namely two mRNA vaccines, two adenoviral vector vaccines and a protein-based vaccine. The immunogenicity and clinical efficacy of these vaccines in the first approval trials were equal or only slightly reduced for older adults compared to younger age groups; however, the concentration of neutralizing antibodies and protection against infection greatly declined over time and the latter is substantially reduced for virus variants, particularly for the Omicron variant. Nevertheless, protection against severe disease and hospitalization is maintained at a high level for longer time periods, and after three vaccine doses (2 + 1 schedule) also for the Omicron variant. Additional booster vaccinations are currently recommended for patients with risk factors, especially older adults. With respect to the currently valid recommendations for different age and risk groups, the publications and notifications of the national vaccine advisory bodies should be referred to. All currently available vaccines target the original virus strain. New vaccines, which are adapted to virus variants are currently being developed and tested, and it is highly likely that they will be used in the near future; however, viral evolution is ongoing and a continuous development of adapted vaccines will probably be necessary.