The role of serological testing for vaccination with a focus on immunocompromised patients: a synthesis of current evidence.

Immunocompromised individuals are at high risk of vaccine-preventable diseases, but typically have impaired immune responses to vaccination and require altered vaccination schedules. Serological testing can inform vaccination decisions in this vulnerable population, but is frequently ordered inappropriately. Furthermore, misinterpretion of serological results can misguide clinical decisions. We reviewed existing recommendations and supporting literature to define key criteria for appropriate serological testing in immunocompromised persons. We identified three key criteria: 1) there must be an established immune correlate of protection; 2) there must be a reliable, validated commercial serology test; and 3) test results must inform clinical decisions around vaccination or post-exposure prophylaxis. Serology results can most accurately guide clinical decision-making for hepatitis B, measles, rabies, rubella and yellow fever. In this article, we provide a synthesis of this published evidence to guide clinicians and vaccine providers on the appropriate utilisation of serological testing.