- Pertussis is a respiratory infection caused by Bordetella pertussis.
- Maternal pertussis vaccination during pregnancy reduces the pertussis risk for infants by more than 90%
Women who received Tdap pertussis booster vaccine during pregnancy may be likely to reduce the risk of contracting pertussis in infants. The risk was reduced by 91% during the first two months of life which is the critical period before they receive the first childhood acellular pertussis (DTaP) vaccine.
The research findings from the Kaiser Permanente Vaccine Study Center was reported in the journal Pediatrics
‘Vaccination can reduce the risk of maternal pertussis in newborns by 91%.’
Pertussis is a respiratory infection caused by Bordetella pertussis which can affect persons of any age. However, it is more life-threatening in infants.
The research study also found that maternal Tdap vaccine during pregnancy may reduce the risk of pertussis by 69% in infants during the first year of life after adjusting for the effects of infant DTaP vaccines administered by starting at the age of two months.
Acellular pertussis DTaP vaccine did not provide the long-term protection of the whole cell vaccine (DTwP) which was replaced.
The research team also found that the protective effect of DTaP may decrease dramatically after the five recommended shots when received around the age of 4-6.
The research findings explained the increasing outbreaks of a whooping cough in United States. The research study also showed the effectiveness for the Tdap booster.
Nicola P. Klein, MD, Ph.D, said, "The strategy of immunizing pregnant women to boost maternal antibody transfer appears to be more effective for protecting young infants against pertussis than are attempts at 'cocooning,' in which mothers and other persons in close contact with newborns are vaccinated after the birth."
The research study was conducted on 148,981 infants born in Kaiser Permanente hospitals in Northern California from 2006-2015.
The percentage of infants whose mother received Tdap vaccine during pregnancy increased from less than 1% in 2006-2008 to about 12% in 2010 and around 87% in 2015.
The maximum number of women who were vaccinated in Kaiser Permanente Northern California from 2010-2015 were found to receive Tdap at 20 weeks gestation or greater, and by 2013, they were most vaccinated between 27-36 weeks of gestation.
Dr. Klein, said, "The results of this study demonstrate that maternal Tdap administered during pregnancy provides the best protection against pertussis, which strongly supports ACIP's current recommendation to administer Tdap during each pregnancy."
Previous studies, found maternal Tdap to be effective in infants before DTaP vaccination. The effectiveness of Tdap during pregnancy about the first three infant doses of DTaP address concerns that maternal Tdap and infant DTap to interfere with each other, thereby decreasing the protection for the infant.
Dr.Klein, said, "Maternal Tdap administered during pregnancy was highly effective at protecting infants against pertussis prior to their first dose of DTaP. Through the first year of life, maternal Tdap continued to provide protection without interfering with DTaP."
"It is reassuring that at every level of DTaP exposure, children with maternal Tdap are better protected."
Primary immunization of Infants with DTaP (Reduced diptheria toxoid, tetanus toxoid, acellular pertussis) vaccines are recommended at 2, 4 and 6 months of age.
During the early months of life, the newborns can benefit from DTaP. They may receive some protection against pertussis from maternal antibodies during pregnancy.
Maternal pertussis antibodies in the infant may decline significantly by 6 weeks of age and become undetectable by 4 months of age.
The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP)in 2013, recommended Tdap vaccination in pregnant women regardless of Tdap vaccine at any time during pregnancy. This may be preferably between 27 and 36 weeks of gestation.
The ACIP recommendations may largely supplant in place 2006, to administer Tdap to mothers in the immediate postpartum period.