With outbreaks of measles a concern both in the United States and abroad due to increasing vaccine hesitancy and refusal, it raises the question about whether infants should be vaccinated at a younger age to better protect them. To answer that question, Science et al (10.1542/peds.2019-0630) studied the presence and duration of protective maternal antibodies in the first year of life among infants in Ontario, where there has not been a case of measles in decades. The authors found that 92% of infants studied had non-protective antibody titers by three months of age, suggesting they were vulnerable to an infection with this virus were an outbreak to occur.
Does this mean we should advocate to the Advisory Committee on Immunization Practices to vaccinate infants prior to 12 months of age, since the vaccine can be given as early as 6 months for an outbreak, or to an endemic area, or as post-exposure prophylaxis? Not necessarily—at least according to an accompanying commentary (10.1542/peds.2019-2541) by vaccine experts Drs. Huong McLean and Walter Orenstein. Drs. McLean and Orenstein remind us that there are risks of immunizing an infant too early and that in the absence of an outbreak, those risks may outweigh the benefits of moving to an earlier routine vaccine schedule for the measles vaccine. Inject some time into reading both studies to understand all sides of the issue in regard to moving the initial measles vaccine earlier. Should more outbreaks occur in this country as a result of vaccine hesitancy or related to cases imported from overseas, these two articles will be important ones to know about and share with your patients.