Pertussis vaccine in pregnant women: safety and uptake

Figures & data

Table 1 Immunization schedules for the prevention of pertussis

Target population	USA ACIP/CDC	UK	WHO
Primary childhood series	DTaP	DTaP	DTPw
	2 months	2 months	6 weeks
	4 months	3 months	10–14 weeks
	6 months	4 months	14–18 weeks
	12–18 months 4–6 years	3–6 years	1–6 years
Adolescent	Tdap 11–12 years (up to 18 years catch up)	Not recommended	Not recommended
Adults	Tdap One dose at any age, including persons over 65 years of age	Not recommended	Not recommended
Pregnant women	Tdap One dose at every pregnancy given at 27–36 weeks of gestation*	Tdap One dose at every pregnancy at 28–32 weeks of gestation (up to 38 weeks)	Not recommended
Other	Tdap Health care personnel Contacts of infants	Not recommended	Tdap Health care personnel in countries with demonstrated high rates of nosocomial transmission

Notes: *Tdap should be administered postpartum in women who were not vaccinated during pregnancy. Breastfeeding is not a contraindication to vaccination. UK immunization schedule: http://www.nhs.uk/conditions/vaccinations/pages/vaccination-schedule-age-checklist.aspx.

Abbreviations: ACIP, Advisory Committee on Immunization Practices; CDC, Centers for Disease Control and Prevention; DTaP, diphtheria, tetanus, and acellular pertussis vaccine; DTPw, diptheria, tetanus, and whole cell pertussis vaccine; Tdap, tetanus, reduced diphtheria and acellular pertussis vaccine; WHO, World Health Organization.

Table 2 Potential benefits and risks of pertussis vaccination during pregnancy

Target population	Potential benefits	Potential risks
Maternal immunization in general	Mothers are capable of responding to vaccine antigens and achieve antibody concentrations similar to those of nonpregnant adults Mothers have regular access to medical care and several opportunities to receive immunizations during pregnancy Prevention of infection is part of good health maintenance in a mother and of a healthy pregnancy	Information regarding maternal immunization in general is based mostly on observational studies, epidemiologic studies, and small clinical trials. However, surveillance systems are in place to evaluate the safety of vaccines recommended in pregnancy, including Tdap, and large clinical trials are in progress or planned to continue to assess the safety and effectiveness of maternal immunization with Tdap
Mother	Vaccination can prevent pertussis infection in the mother Prevention of the consequences of infection that may affect the pregnancy, such as fever, preterm labor, or preterm delivery, are a result of vaccination	vaccine safety is important to consider including the risk of: – Fever – Systemic reactogenicity – Allergic/anaphylactic reactions There are no safety concerns reported to date with the use of Tdap vaccine in pregnancy
Fetus	A healthy mother and pregnancy results in a healthy fetus that is more likely to grow and complete a term pregnancy Use of vaccines in the second or third trimester of gestation minimizes any potential risk of embryotoxicity or teratogenicity	Use of live vaccines should be avoided given theoretical risk of infection to the fetus (no live vaccines are currently in use for pertussis prevention) There are no theoretical safety concerns with the use of effective inactivated vaccines during pregnancy
Newborn and infant	Transplacental passage of maternal antibodies protects infants against pertussis infection before they are able to be immunized Newborns receive high concentrations of antibodies when mothers are vaccinated during the second or third trimester of gestation The half-life of the passively acquired antibodies is such that high concentrations are still present at 2 months of age, when routine infant vaccination against pertussis begins Infants may also benefit from breast milk antibodies which are found in high concentrations after maternal vaccination vaccination of women during pregnancy provides the most direct and efficient protection to newborns and young infants against pertussis	High levels of maternal antibody may interfere with the infant’s ability to respond to active immunization with high concentrations of antibody. However, priming with active immunization is preserved, and infants of mothers who are vaccinated with Tdap display an adequate booster response to vaccination

Abbreviation: Tdap, tetanus, reduced diphtheria and acellular pertussis vaccine.