What are the recommendations for whooping cough vaccination during pregnancy in women with Methylenetetrahydrofolate Reductase (MTHFR) mutation?

Whooping Cough Vaccination During Pregnancy for Women with MTHFR Mutation

Women with MTHFR mutation should receive the Tdap vaccine during pregnancy between 27-36 weeks gestation, preferably earlier in this window (27-32 weeks) to maximize maternal antibody transfer to the infant, just as recommended for all pregnant women. 1

Recommendations for Tdap Vaccination During Pregnancy

Timing of Vaccination

• Tdap should be administered during each pregnancy, regardless of prior Tdap vaccination history 1
• The optimal timing is between 27-36 weeks gestation, with evidence suggesting that vaccinating earlier in this window (27-32 weeks) maximizes maternal antibody transfer to the infant 1
• Vaccinating during this period is 80-91% effective in preventing pertussis in newborns 1
• Maternal vaccination has been shown to be 58% effective in preventing hospitalization among infants infected with pertussis 1

Rationale for Vaccination

• Young infants are at greatest risk for hospitalization and death due to pertussis 1
• Infants do not begin their own vaccine series against pertussis until approximately 2 months of age, leaving them vulnerable during the first weeks of life 2
• Maternal vaccination provides passive immunity to newborns through transplacental antibody transfer 1, 2
• Studies have shown that infants whose mothers received Tdap during pregnancy had higher concentrations of pertussis antibodies at birth compared to those of unvaccinated mothers 1

MTHFR Mutation and Vaccination

There are no specific contraindications or special considerations for Tdap vaccination in women with MTHFR mutations mentioned in any of the guidelines. The ACIP recommendations apply to all pregnant women, including those with MTHFR mutations 1.

The contraindications for Tdap vaccination are:

• Severe allergic reaction (e.g., anaphylaxis) after a previous dose or to a vaccine component 1
• Encephalopathy not attributable to another identifiable cause within 7 days of administration of a previous pertussis-containing vaccine 1

Special Situations

Incomplete Tetanus Vaccination

• Pregnant women who have never been vaccinated against tetanus should receive a series of three vaccinations containing tetanus and diphtheria toxoids 1
• The recommended schedule is 0,4 weeks, and 6-12 months 1
• Tdap should replace one dose of Td in this series, preferably between 27-36 weeks gestation 1

Wound Management

• If a tetanus booster is indicated for wound management during pregnancy (≥5 years since previous Td), Tdap should be administered 1
• For pregnant women with a history of Arthus reaction after a previous dose of tetanus toxoid-containing vaccine, vaccination should be deferred until 10 years or more after the most recent dose 1

Effectiveness of Maternal Tdap Vaccination

• Prenatal Tdap vaccination at 27-36 weeks gestation is 85% more effective than postpartum vaccination at preventing pertussis in infants under 8 weeks of age 3
• Immunization early in the third trimester (27-30 weeks) is associated with the highest concentrations of pertussis antibodies in newborns 4
• Geometric mean concentrations of pertussis toxin antibodies were highest when Tdap was administered during weeks 27-30, reaching a peak at week 30 4

Important Clinical Considerations

• Tdap vaccination is recommended during each pregnancy, regardless of prior Tdap vaccination history, as antibody levels wane substantially within one year 1
• There is no evidence of adverse fetal effects from vaccinating pregnant women with inactivated virus, bacterial vaccines, or toxoids 2
• Despite high vaccination coverage, pertussis incidence has been increasing in the United States, making maternal vaccination particularly important 1
• Household contacts and caregivers of infants should also be vaccinated against pertussis to provide "cocooning" protection 1

In summary, MTHFR mutation status does not alter the recommendation for Tdap vaccination during pregnancy. All pregnant women, including those with MTHFR mutations, should receive Tdap vaccination between 27-36 weeks gestation, preferably earlier in this window, to optimize protection for their newborns against pertussis.