One in Five Newborns May Lack Measles Antibodies Passed Down From Their Mothers

In an observational study, researchers from the Children’s Hospital of Philadelphia and the University of Pennsylvania, found that one in five newborns may not have measles antibodies passed down from their mothers.

The researchers used biobank serum samples that were collected from patients admitted to one of two hospitals in Philadelphia, PA from April 2021 to October 2021. The data included qualitative results from routine prenatal rubella IgG measurements that were collected up to 270 days before delivery, which is a routine test during the time of pregnancy.

In total, 4886 patients gave birth during the study period. The researchers randomly selected 550 patients to use in the study’s analysis. Of the 550 patients, 97.3% (n = 535) tested positive for rubella, and 93.3% (n = 513) had an available serum sample for measles testing, and 90.0% (n = 500) had both. Of the total patients who were positive for rubella, 8.0% (n = 43) were seronegative for rubella. Measles seronegativity was documented in 20.1% of the total patients who tested with measles (n = 103).

Overall, one in five parturient patients resulted in being seronegative for measles. The researchers suggest that one in five newborns lack measles antibodies, which would be maternally derived.

“These findings underscore the need for a more detailed understanding of how maternal measles serostatus could be used to optimize infant protection during measles outbreaks,” the researchers wrote. “Infants born to seropositive mothers may not benefit from early vaccination during outbreaks given decreased immunogenicity in the presence of maternal measles antibodies. Infants born to seronegative mothers, however, may benefit from supplemental early vaccination during measles outbreaks.”

The study did have limitations including the fact that two centers from one urban location were used in the study and serological immunity may have differed from clinical immunity as patients who are seronegative may maintain immunity by an anamnestic antibody response.

Reference:

Flannery DD, Barboza AZ, Wade KC, et al. Measles serostatus among parturient patients at 2 Philadelphia hospitals in 2021. JAMA. Published online February 3, 2023. doi:10.1001/jama.2023.0166