Post-exposure passive immunisation for preventing measles
Injecting antibodies into a muscle of people who came into contact with measles, but lacked their own antibodies, was effective at preventing them catching the disease compared to those who received no treatment.
Passive immunization is generally considered to prevent measles in someone who is not immune and has been exposed to infection. This review assesses the effectiveness and safety of intramuscular injection or intravenous infusion of immunoglobulins for preventing measles when administered to exposed susceptible people before the onset of symptoms. The group of susceptible people are considered those without antibodies. Based on seven studies that fit the inclusion criteria (1432 participants), the review found when using the modern-day antibody preparation, people were 83% less likely to develop measles than those who were not treated. However, only two studies compared the measles vaccine with the antibody injection in this group of people, so no firm conclusions could be drawn about the relative effectiveness of these interventions. In addition, these studies did not include pregnant women, infants and immunocompromised in the participation group, so they are not included in findings. As well, no minimum dosage of antibodies required to reach effectiveness was measured in the studies.