To Vaccinate or Not To Vaccinate: A Laboratory Perspective
Protection from infectious disease has been a quest since the beginning of human history. A major advancement in this endeavor was the development of vaccines. Although we do not have vaccines for every infectious microorganism, today there are vaccines for 30 diseases. Vaccines don’t always prevent infection and transmission altogether, but they do work to prevent or ameliorate/mitigate disease by reducing complications and symptoms through the generation of memory and protective antibody-producing B cells and T cells. Laboratory serology testing, which measures concentrations of antibodies specific to particular microorganisms, is a useful and important tool for determining exposure and, for a handful of vaccine-preventable diseases, for assessing immunization status associated with immunity. For some common vaccine-preventable diseases with high global impact—such as hepatitis B, measles, mumps, and rubella—determining vaccine status is sometimes necessary for a variety of reasons. Determining vaccine status is useful for women considering pregnancies, healthcare workers, and vulnerable populations (i.e., very young individuals and patients with cancer) at risk of severe complications from natural infections. Awareness of the limitations of serology testing, coupled with appropriate test result interpretation for assessing vaccine status associated with immunity, is vital to patient care. Most importantly, although laboratory evidence of immunization status is key to optimal patient management, it is only one criterion in the decision to vaccinate or not to vaccinate.
