Vaccines - safety in pregnancy

Abstract

Vaccination during pregnancy is important for active immunity of the mother against serious infectious diseases, and also for passive immunity of the neonate to infectious diseases with high morbidity and mortality. As a rule, live vaccines are contraindicated during pregnancy as they may cause fetal viremia/bacteremia. Inactivated vaccines are generally safe. Vaccines safe to be administered to all pregnant ladies are tetanus toxoid (TT; tetanus, diphtheria, acellular pertussis (Tdap) and Flu vaccines. During pre-pregnancy counselling, vaccination for MMR (measles, mumps, and rubella) should be offered, with an advice to avoid pregnancy for a month. All pregnant mothers should receive TT and Tdap vaccination during the third trimester. Flu vaccine can be given to all mothers at any gestation, and if not offered during pregnancy, it can be given postpartum. Vaccinations that should be offered to women if at high risk of exposure are for hepatitis A and B, pneumococcal, meningococcal, yellow fever, Japanese encephalitis (JE), polio, typhoid, and cholera infections. Vaccines to be given only for post-exposure prophylaxis (PEP) are smallpox, rabies, and anthrax. Postpartum women should be offered human papillomavirus (HPV) vaccination. If not immunized earlier, they should be offered MMR, Tdap, and Flu vaccines. Future vaccines being developed are for malaria, Zika virus, respiratory syncytial virus (RSV), group B streptococcus, CMV, and COVID-19 (SARS-Cov-2).

Keywords: Immunization; Pregnancy; Safety in pregnancy; Vaccination.

Fig. 1

Formation of a vector vaccine.

Fig. 2

Maternal immune response during pregnancy (A) and breast feeding (B) [18].

Fig. 3

Life Cycle of Malaria Parasite. Schematic life cycle of Plasmodium falciparum showing where vaccination may be expected to intervene. A transmission-blocking vaccine targets the parasite during its sexual development within the Anopheles mosquito host.