Vaccines and Pregnancy

Vaccines in pregnancy protect the mother and, through transplacental antibody, the newborn in the first months of life. Inactivated, toxoid, recombinant and mRNA vaccines are safe at any gestation when indicated; live attenuated vaccines are contraindicated because of theoretical foetal infection.

Principles. Give vaccines that are routinely advised in pregnancy at the best time for infant protection; give indicated vaccines for exposure or travel risk; postpone non-urgent vaccines until after birth; never delay a vaccine needed for post-exposure protection.

Pregnancy planning. Check rubella and varicella immunity before pregnancy; give live vaccines at least 4 weeks (1 month) before conception.

Routinely advised.

• Tetanus toxoid or tetanus-diphtheria-pertussis: 0.5 mL IM. Unimmunised: 2 doses at least 4 weeks apart, the second at least 2 weeks before birth; then further doses to complete 5 doses over life. Tetanus, diphtheria and acellular pertussis vaccine 0.5 mL IM at 16 to 32 weeks (many programmes 27 to 36 weeks) in every pregnancy.
• Inactivated influenza vaccine 0.5 mL IM, any trimester, during the local season.
• COVID-19 mRNA or other approved non-live vaccine, any trimester, following current local schedules.
• Respiratory syncytial virus prefusion F vaccine 120 micrograms IM as a single dose at 24 to 36 weeks in seasonal programmes (maternal vaccination or infant monoclonal antibody, not both).

Indicated by risk.

• Hepatitis B (non-immune, at risk): 3 doses at 0, 1 and 6 months (20 micrograms of antigen each); newborn of an infected mother needs hepatitis B immunoglobulin 100 to 200 units IM and vaccine within 12 hours of birth.
• Hepatitis A inactivated vaccine for travel or outbreak.
• Pneumococcal conjugate or polysaccharide and meningococcal conjugate vaccines for indications (asplenia, HIV, outbreak).
• Rabies: pre- and post-exposure vaccine and immunoglobulin are never withheld because of pregnancy (post-exposure: 4 to 5 dose schedule on days 0, 3, 7 and 14 plus immunoglobulin 20 units/kg infiltrated around the wound).
• Typhoid Vi polysaccharide or conjugate in outbreak; oral cholera vaccine (inactivated, in outbreak or high risk).
• Yellow fever (live): avoid unless exposure risk is high (outbreak or unavoidable travel) after risk-benefit review; give the full indicated dose in those cases.

Contraindicated, live attenuated. Measles, mumps and rubella; varicella; BCG; oral typhoid; nasal influenza; oral rotavirus. Give measles, mumps and rubella and varicella vaccines after birth (breastfeeding is not a contraindication); check rubella status at booking and vaccinate before discharge if non-immune.

Polio. Inactivated poliovirus vaccine is preferred; oral poliovirus vaccine is avoided except in an outbreak or in an area with ongoing transmission.

Human papillomavirus. Postpone until after birth. Inadvertent doses need no intervention.

Anti-D immunoglobulin. It is not a vaccine and does not interfere with vaccines other than live vaccines (defer measles, mumps, rubella and varicella by 3 months after anti-D).

Adverse events. Local pain, fever and myalgia are common. Fever should be treated with paracetamol 1 g (maximum 4 g daily) because maternal fever over 38 °C in the first trimester carries a small neural tube risk. Anaphylaxis is rare: adrenaline 500 micrograms IM into the anterolateral thigh, repeated after 5 minutes if needed.

Contraindications. Anaphylaxis to a previous dose or component; live vaccines in pregnancy and in immunosuppression.

Interactions. Immunosuppressants (prednisolone 20 mg or more daily, TNF inhibitors, rituximab) may blunt response; time vaccines before planned immunosuppression where possible. Anticoagulation: use a fine needle and apply pressure for 2 minutes after injection.

Special groups.

• HIV: give inactivated vaccines as normal; avoid live vaccines at low CD4 counts.
• Kidney and liver impairment: give hepatitis B vaccine at double dose (40 micrograms) in dialysis.
• Preterm labour and chorioamnionitis: delay until stable.
• Breastfeeding: all vaccines are compatible; yellow fever vaccine is avoided in mothers breastfeeding infants under 9 months unless exposure is unavoidable (vaccine virus transmission reported).
• Regional: tetanus protection (including neonatal tetanus prevention by 2 or more doses) and pertussis protection remain core maternal tasks in East Africa. Hepatitis B birth dose within 24 hours supports infant protection where maternal status is unknown.

Monitoring. Observe for 15 to 30 minutes after vaccination for immediate reactions and keep adrenaline available. Record vaccine, batch, date and site in the patient record.

Schedule adjustment. Do not restart a course; resume it after a delay. Give missed Tdap doses at any time later in pregnancy or immediately after birth if not given antenatally.

Stopping rules. None. Withhold the next dose only after a severe reaction.

Referral and escalation. Refer inadvertent exposure to a live vaccine in pregnancy to an obstetric or infectious diseases specialist for counselling (no routine termination is advised); refer suspected anaphylaxis to emergency care. Notify adverse events through the local pharmacovigilance system.