Pertussis, commonly known as "whooping cough," is a highly contagious respiratory disease caused by the bacteria Bordetella pertussis. Since the pertussis vaccine has been available, infant mortality due to whooping cough has decreased drastically. Nonetheless, there have been persistent increases in pertussis in the US, and the CDC and the Advisory Committee on Immunization Practices (ACIP) have updated recommendations for the use of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in pregnant women. In October 2012, the ACIP voted to recommend that a dose of Tdap should be administered during each pregnancy regardless of the patient's prior Tdap or tetanus and diphtheria vaccination history. The new recommendation was issued due to a need to minimize the burden of pertussis in newborns, the safety data from Tdap use in adults, and concerns with waning immunity after immunization.

Pertussis can cause serious and sometimes life-threatening complications in infants, especially within the first 6 months of life, because they have underdeveloped immune systems and are more easily susceptible to infections. It is a very contagious disease that can be spread from person to person usually by coughing, sneezing, or being in close contact for a prolonged period of time. Older siblings, parents, or caregivers who might not even know they have the disease may infect infants with pertussis. Although coughing is the most prevalent symptom, many infants with pertussis do not show symptoms of coughing. The younger the infant is when contracting pertussis, the more likely it is that it will need to be treated in the hospital. Of those infants who are hospitalized with pertussis, about 1 out of 4 will develop pneumonia and 1 out of 100 will die. Other complications include convulsions, apnea, and encephalopathy.

The pertussis booster vaccine administered in adolescents and adults, known as Tdap vaccine, provides protection against three different diseases—tetanus, diphtheria, and pertussis. It should also be given to anyone in these age groups who will be in close contact with an infant younger than 12 months or close contact with a pregnant mother. The recommended time of vaccination for expectant mothers is from gestational weeks 27 through 36. Because the level of pertussis antibodies decreases over time, Tdap should be administered during every pregnancy so that the greatest number of protective antibodies can be transferred to each infant. Postpartum Tdap administration can only provide protection to the mother, and it could take about 2 weeks after administration for the mother to have protection against pertussis. Until the mother develops protection, she is at risk for contracting and spreading pertussis to her vulnerable infant. The vaccine should only be administered postpartum if a woman has never received Tdap before. Repeat postpartum vaccination is not an ACIP recommendation.

According to a cohort study of 16 infants whose mothers received the Tdap vaccine during pregnancy and 54 control infants whose mothers did not, higher pertussis antibody concentrations (3.2- to 22.8-fold greater) persisted at the first diphtheria, tetanus, and acellular pertussis (referred to as DTaP, which is the pertussis childhood vaccine) dose in the maternal Tdap group than in the control group. The study supported the recommendation for Tdap vaccination of all women during each pregnancy and concluded that it may increase protection of infants <6 months of age and decrease pertussis morbidity and mortality in this population.

The CDC strongly advises for all pregnant women to receive the Tdap vaccine, and it also encourages others who will have contact with the infant (eg, fathers, grandparents, and other infant caregivers) to get vaccinated in order to form a "cocoon" of disease protection. In this way, exposure to the infection can be minimized. Tdap vaccine is available for administration at pharmacies without a prescription for certain age groups in some states.

Please update or register your profile to receive email alerts and other critical drug information updates from PDR. You can also stay current by using the official PDR app, available now for free from your favorite app stores.