NEW YORK (Reuters Health) – Health providers should pay extra attention to infants with signs of pertussis given the potential interaction between maternal vaccination for the disease and the baby’s responses to diphtheria, tetanus, and whole-cell pertussis (DTwP) vaccination, according to a new opinion piece in Pediatrics.
In an earlier study in the U.S., high maternally derived antibody levels in infants interfered with DTwP vaccination, used almost exclusively in low-and middle-income countries (LMICs), but not with diphtheria-tetanus-acellular pertussis (DTaP) vaccination, used in most high-income countries (HICs).
With the growing uptake of acellular pertussis-containing vaccine in pregnancy to prevent severe pertussis in young infants, the likelihood of interference with infant pertussis vaccination is increasing, according to Dr. Bahaa Abu-Raya of The University of British Columbia, in Vancouver, Canada, and Dr. Kathryn M. Edwards of Vanderbilt University School of Medicine, in Nashville, Tennessee.
While interference is unlikely to pose a clinical problem in the U.S., they say, the clinical significance of interference with DTwP is more difficult to ascertain in LMICs because of the lack of comprehensive surveillance systems.
Switching from DTwP to DTaP in countries with maternal pertussis vaccination programs could mitigate any clinical effect, but current DTaP vaccines are more costly than DTwP vaccines, and waning immunity to the available DTaP vaccine formulations represent another challenge.
Delaying the initiation of pertussis primary vaccination in infants born to pertussis-vaccinated mothers could also mitigate the impact of interference, but the strategy would likely be complicated by World Health Organization recommendations that encourage countries to achieve early and timely vaccination, the authors argue.
Moreover, other vaccine antigens are commonly administered between 6 and 8 weeks of age and are often given in combination with pertussis antigens.
Investigations into the mechanism of interference might also shed light on new approaches to mitigate its effect.
In the meantime, the authors conclude, “Providers in both HICs and LMICs should investigate infants with symptoms suggestive of pertussis disease, even if the disease is mild or the symptoms are nonclassic. Pertussis-confirmed cases should be reported, along with maternal immunization history, to help determine if interference has clinical significance.”
Dr. Abu-Raya did not respond to a request for comments.
SOURCE: https://bit.ly/31hcxEP Pediatrics, online August 4, 2020.