Nonimmune children exposed to measles during a 2013 outbreak in New York City were significantly less likely to develop the disease if they received post-exposure prophylaxis with the measles, mumps and rubella vaccine or immune globulin, according to a recent analysis.
The findings support recommendations from the CDC’s Advisory Committee on Immunization Practices (ACIP) on measles post-exposure prophylaxis (PEP) use and add to existing literature on its efficacy, which Robert J. Arciuolo, MPH, CPH, city research scientist at the New York City Department of Health and Mental Hygiene (DOHMH), and colleagues said is “limited and variable.”
According to the researchers, the ACIP recommends administering PEP with the measles, mumps and rubella (MMR) vaccine to nonimmune patients aged 6 months or older within 72 hours of exposure, or immune globulin (IG) PEP to infants who did not receive MMR PEP within 72 hours, severely immunocompromised patients, or pregnant women with no evidence of measles immunity within 6 days of exposure.
“IG PEP also may be considered for persons without evidence of immunity who are exposed in settings with intense, prolonged, close contact, such as in a household or day care setting,” they added.
Arciuolo and colleagues assessed the efficacy of PEP administered to children and adolescents who were exposed to measles during an outbreak in New York City. The outbreak was linked to an infected traveler returning to the United States from London in March 2013. It spread among members of Orthodox Jewish communities through June 2013. Over the course of the outbreak, DOHMH officials identified 3,409 contacts, 58 of whom developed measles.
In their analysis, Arciuolo and colleagues examined data on 318 nonimmune contacts aged younger than 19 years. Thirty-eight percent of these contacts received PEP in accordance with ACIP guidelines. Among them, 14% received MMR PEP and 24% received IG PEP.
Forty-eight of the 318 contacts developed measles, including two who received MMR PEP. The researchers estimated that MMR PEP was 83.4% (95% CI, 34.4%-95.8%) effective and IG PEP was 100% (95% CI, 56.2%-99.8%) effective. The overall efficacy of any measles PEP was 92.9% (95% CI, 71.4%-98.3%).
“These findings indicate that timely administration of measles PEP is a highly effective control measure for preventing measles transmission,” the researchers concluded. “Future studies to evaluate the effect of timing of measles PEP administration on PEP effectiveness both within and beyond the recommended time interval are warranted.” – by Stephanie Viguers
The authors report no relevant financial disclosures.