Receiving the first dose of the pertussis vaccine significantly reduces the risk of death, hospitalization, and pneumonia among infants who contract the illness, a recent study found.
“Health professionals should ensure on-time first-dose pertussis vaccination as early as 6 weeks of age during pertussis outbreaks and provide early recommended antibiotic treatment,” said Dr. Tejpratap S.P. Tiwari and colleagues at the Centers for Disease Control and Prevention, Atlanta. “Infants who are age-ineligible for vaccination will benefit from strengthening strategies that provide immunity to newborns and prevent exposure to [Bordetella] pertussis,” they wrote (Pediatrics 2015 (doi:10.1542/peds.2014-2291).
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Dr. Tiwari’s team reviewed all cases of pertussis in infants under age 1 year that had been reported to the National Notifiable Diseases Surveillance System (NNDSS) and the Centers for Disease Control and Prevention between 1991 and 2008. Among 45,404 reported cases, 258 deaths (0.57%) occurred.
All of the children who died had contracted pertussis before age 34 weeks, and 64% of the deaths occurred in children younger than 6 weeks. Overall, 90% of nonfatal cases occurred in infants younger than 34 weeks. The older children were, the less likely they were to die from the disease: the case fatality rate dropped from 2.36% at age 1 week to 0.28% at age 12 weeks. No significant differences in sex were observed.
Infants at least 42 days old who had received at least one dose of DTaP were 72% less likely to die from the illness after adjusting for onset age, race, and antibiotic treatment (adjusted odds ratio, 0.28). They were also 31% less likely to be hospitalized and 20% less likely to develop pneumonia (aOR, 0.69 and 0.80, respectively). Babies who received the recommended antibiotics were 72% less likely to die than those who didn’t receive the drugs (aOR, 0.28).
Hispanic infants with pertussis were more than twice as likely to die than were non-Hispanic infants with the illness, with a case fatality rate of 1.26% for Hispanic infants and 0.75% for non-Hispanic infants (aOR, 2.28, compared with white infants). American Indian/Alaska Native infants had a more than five times greater odds of death and a case fatality rate of 1.85% (aOR, 5.15).
The researchers calculated that on-time vaccination could have prevented 72% of the deaths occurring after 8 weeks, resulting in a 16% reduced fatality rate.
The research was funded by the CDC. The authors reported no relevant financial disclosures.