[When are antibody determinations in serum before or after vaccination indicated and when not?]

Questions about the usefulness of determining antibody values or titers to demonstrate protection often arise before or after vaccinations in immunization clinics. Such measurements may be useful in exceptional situations, e.g., in immunocompromised patients or those with suspected immunodeficiency, in patients with unknown vaccination status, and in certain defined risk situations (e.g., hepatitis B serology after needlestick injuries or after COVID-19 vaccination in patients with certain forms of immunodeficiency). In contrast, individual serological antibody measurements are neither recommended nor useful after generally recommended vaccinations. This is because either it is known from licensure studies or long-term use that there is a sufficiently high individual probability of protection (e.g., > 99% for tetanus) when the recommended vaccination schedules are adhered to or because the vaccination strategy is primarily aimed at indirect protection of the population and not at protection of each individual person. The few individuals who are not sufficiently protected after vaccination (vaccination failures) will still benefit indirectly from the reduced risk of exposure. This has been demonstrated with oral poliomyelitis vaccination in the 1960s, MMR vaccination since the 1970s, and Hib vaccination since the 1990s. This statement of our committee shows the evidence for a sensible approach, when and which antibody determinations are helpful and meaningful after or before vaccination and which are not. The statement is based on Germany's Standing Committee on Vaccination (STIKO) recommendations and their administration instructions. We advise not to comply with the wish of some parents for titer determinations in their child that are not medically justified.