What vaccinations, such as Influenza (flu) and Tdap (tetanus, diphtheria, and pertussis), are recommended before conception?

Preconception Vaccination Recommendations for Influenza and Tdap

Women planning pregnancy should receive the inactivated influenza vaccine before conception if they will be pregnant during flu season, while Tdap vaccination is NOT routinely recommended preconception—instead, Tdap should be administered during each pregnancy between 27-36 weeks' gestation. 1, 2

Influenza Vaccination Before Conception

Timing and Rationale

• Administer inactivated influenza vaccine (IIV) before conception if pregnancy will occur during influenza season (October-May) to establish maternal immunity that protects both mother and fetus. 2, 3
• The vaccine can be given at any time during pregnancy if not received preconception, as pregnancy is not a contraindication to inactivated influenza vaccine. 1, 2
• Pregnant women face disproportionately higher risks from influenza infection, including increased rates of severe illness and adverse pregnancy outcomes, making vaccination critical. 1, 3

Key Safety Considerations

• Only use inactivated influenza vaccine (IIV) or recombinant influenza vaccine (RIV)—never live attenuated influenza vaccine (LAIV) in women who are or may become pregnant, as LAIV is contraindicated due to theoretical risk of placental viral transmission. 1
• Severe allergic reaction (anaphylaxis) to previous influenza vaccine or vaccine components (including egg protein for IIV) is a contraindication. 1
• History of Guillain-Barré syndrome within 6 weeks of previous influenza vaccination is a precaution requiring careful risk-benefit assessment. 1

Tdap Vaccination Strategy

Current Guideline Recommendations

Tdap is NOT recommended as a routine preconception vaccine—instead, it should be administered during EACH pregnancy between 27-36 weeks' gestation, regardless of prior vaccination history. 1, 2

This represents a critical shift from older guidance:

• Earlier 2008 ACIP recommendations suggested postpartum Tdap administration 1
• Current 2018 ACIP guidelines mandate Tdap during every pregnancy to maximize passive antibody transfer to the infant, providing protection during the vulnerable first months of life before the infant can receive DTaP vaccines. 1

Rationale for Pregnancy Administration Over Preconception

• Administering Tdap between 27-36 weeks' gestation (preferably earlier in this window) maximizes transplacental antibody transfer to provide passive immunity to the newborn. 1
• Pertussis mortality and severe disease risk is highest in infants during the first months of life, before they receive their own DTaP series starting at 2 months. 1
• Maternal antibody levels peak 1-2 weeks after vaccination, making late pregnancy administration optimal for infant protection. 1

Special Preconception Scenarios

The only situation where preconception Tdap may be considered is for women who have not received Tdap previously AND are at increased risk for pertussis exposure (e.g., healthcare workers, those in outbreak settings). 1

However, even in these cases:

• The woman should still receive Tdap again during pregnancy (27-36 weeks) to optimize infant protection. 1
• Standard adult Tdap recommendations apply: one dose for adults ≥19 years who have never received Tdap, regardless of interval since last Td. 1

Postpartum Vaccination for Missed Opportunities

If Tdap Not Given During Pregnancy

• Administer Tdap immediately postpartum (before hospital discharge) if the woman never received Tdap during pregnancy or at any prior time. 1
• If the woman received Tdap during a previous pregnancy but not the current one, postpartum Tdap is NOT indicated. 1
• Postpartum administration provides some maternal protection and reduces risk of exposing the infant to pertussis, though it is less effective than pregnancy administration for infant protection. 1

Practical Implementation Algorithm

For Women Planning Pregnancy:

1. Assess influenza vaccine status:

   • If planning pregnancy during flu season (October-May) and not recently vaccinated, administer inactivated influenza vaccine now. 2, 3
   • Document that annual influenza vaccination will be needed if pregnancy extends into subsequent flu seasons. 2

2. Assess Tdap status:

   • Document whether woman has ever received Tdap (as adolescent, adult, or during previous pregnancy). 1
   • Counsel that Tdap will be required during pregnancy (27-36 weeks) regardless of prior vaccination history. 1, 2
   • Do NOT routinely administer Tdap preconception unless special circumstances exist (healthcare worker, outbreak setting). 1

3. Ensure tetanus/diphtheria protection:

   • If >10 years since last Td and woman has special circumstances requiring immediate protection, consider Td (not Tdap) to maintain tetanus immunity. 1
   • This does not replace the need for Tdap during pregnancy. 1

Common Pitfalls to Avoid

• Do not give Tdap preconception thinking it replaces the pregnancy dose—current guidelines require Tdap during EACH pregnancy for optimal infant protection. 1
• Do not use live attenuated influenza vaccine (LAIV, nasal spray) in women who are or may become pregnant—only inactivated or recombinant formulations are safe. 1
• Do not delay influenza vaccination waiting for pregnancy—if flu season is approaching, vaccinate now as the vaccine is safe throughout pregnancy. 2, 3
• Do not administer Tdap at intervals <2 years from last Td in the preconception period unless there are compelling reasons (outbreak, high-risk exposure), as this increases risk of local reactions without clear benefit. 1
• Do not confuse adult Tdap with pediatric DTaP—these are different formulations and DTaP should never be used in adults. 1

Simultaneous Administration

• Influenza vaccine and Tdap can be administered simultaneously during pregnancy using separate syringes at different anatomic sites (e.g., different deltoid muscles). 1, 4
• Administering all indicated vaccines during a single visit increases likelihood of completion and is explicitly recommended by ACIP. 1, 4
• No more than two injections per muscle, separated by at least one inch. 1, 4

Contraindications and Precautions

Absolute Contraindications to Tdap:

• Severe allergic reaction (anaphylaxis) to any vaccine component. 1, 4
• Encephalopathy within 7 days of previous pertussis-containing vaccine not attributable to another cause. 1, 4

Precautions for Tdap:

• Moderate or severe acute illness with or without fever (defer until resolved). 1, 4
• Guillain-Barré syndrome within 6 weeks of previous tetanus toxoid-containing vaccine. 1
• History of Arthus-type hypersensitivity after previous tetanus or diphtheria toxoid (defer until ≥10 years since last dose). 1
• Progressive or unstable neurologic disorder until condition stabilizes. 1

Conditions NOT Contraindications:

• Stable neurologic conditions including well-controlled seizures. 1
• Immunosuppression or HIV infection (though immunogenicity may be suboptimal). 1
• Breastfeeding. 1
• Minor concurrent illness. 1