What are the latest vaccination guidelines for pregnant women?

Vaccination in Pregnancy: Latest Guidelines

Routinely Recommended Vaccines

All pregnant women should receive two vaccines during every pregnancy: inactivated influenza vaccine during any trimester and Tdap vaccine between 27-36 weeks of gestation, as these vaccinations significantly reduce maternal and neonatal morbidity and mortality from severe infections. 1, 2

Influenza Vaccination

• One dose of inactivated influenza vaccine is recommended during any trimester of pregnancy, with administration before flu season being optimal 1
• The CDC and WHO both prioritize pregnant women for seasonal influenza vaccination, with WHO recommending year-round availability 1
• Pregnant women face 7.2% higher hospitalization rates and disproportionately high mortality risk from influenza compared to non-pregnant women 1
• Influenza infection during pregnancy increases risk of late pregnancy loss (adjusted HR 10.7; 95% CI 4.3-27.0) and reduced infant birthweight 1
• The live attenuated intranasal influenza vaccine is contraindicated during pregnancy due to theoretical risk of placental viral transmission 1, 2
• Maternal antibodies transfer through both placenta and breast milk, providing infant protection for up to 6 months 1

Tdap Vaccination

• One dose of Tdap is recommended between 27-36 weeks of gestation during every pregnancy, regardless of prior vaccination history 1, 2
• Optimal timing is 27-28 weeks to maximize maternal antibody response and passive transfer to the infant 2
• This strategy provides 91% protection against pertussis for infants in the first three months of life, when they are most vulnerable 3
• If not administered during pregnancy, Tdap should be given immediately postpartum 1, 2
• For wound management during pregnancy, Tdap can be given earlier if indicated 1, 2

Vaccines Safe Under Special Circumstances

High-Risk Situations

• Hepatitis B vaccine is recommended for pregnant women at risk of HBV infection, as there is no evidence it prevents infant infection but poses no safety concerns 1, 2
• Meningococcal vaccines (conjugate and polysaccharide) are safe and can be given if the woman is at high risk or during an outbreak 1
• Pneumococcal polysaccharide vaccine should be considered for women at increased risk of pneumococcal infection 1, 2
• Hepatitis A inactivated vaccine can be used after consideration of exposure risks, with no evidence of increased adverse pregnancy outcomes 1

Travel-Related Vaccines

• Yellow fever vaccine should be administered to pregnant women traveling to high-risk endemic areas, as the infection risk substantially outweighs theoretical vaccination risks 1, 2
• Inactivated Japanese encephalitis vaccine may be considered if traveling to endemic areas with significant exposure risk 1
• Inactivated polio vaccine (IPV) can be administered to pregnant women at risk for wild-type poliovirus exposure 1
• Inactivated cholera vaccine is safe based on studies of nearly 3,000 women, with WHO recommending inclusion of pregnant women in vaccination campaigns 1

Post-Exposure Prophylaxis

• Rabies vaccine should always be administered following potential exposure regardless of pregnancy status, as rabies has nearly 100% mortality once symptomatic 4
• Pre-exposure rabies prophylaxis may also be indicated if substantial exposure risk exists 4
• No increased incidence of abortion, premature births, or fetal abnormalities has been associated with rabies vaccination 4

Contraindicated Vaccines

Live attenuated vaccines are contraindicated during pregnancy due to theoretical risk of fetal infection through placental transmission. 1, 2, 5

Absolute Contraindications

• Measles, mumps, rubella (MMR) - although no cases of congenital rubella syndrome have been documented in women inadvertently vaccinated during pregnancy 1, 2
• Varicella vaccine - despite no documented abnormalities attributable to fetal infection in exposed pregnancies 1, 2
• Smallpox (vaccinia) - the only vaccine known to cause actual fetal harm; also contraindicated for household contacts of pregnant women 1
• Live attenuated influenza vaccine (intranasal) 1, 2
• Live attenuated cholera, polio, hepatitis A, and Japanese encephalitis vaccines 1

Important Counseling Points

• Women should be asked if they are pregnant or planning pregnancy within 4 weeks before administering live vaccines 1
• Women receiving MMR, varicella, or MMRV should be counseled not to become pregnant for 4 weeks after vaccination 1
• Routine pregnancy testing before live-virus vaccination is not recommended 1
• Susceptible women should be vaccinated immediately postpartum 2

General Safety Principles

Inactivated Vaccines

• Inactivated, recombinant, subunit, polysaccharide, conjugate vaccines and toxoids pose no risk during pregnancy 1
• No evidence exists of risk from vaccinating pregnant women with inactivated virus or bacterial vaccines 1
• Aluminum hydroxide and CpG 1018 adjuvants are considered safe for use in pregnancy 1
• mRNA vaccines have initial safety data supporting safe use in pregnant women 1

Risk-Benefit Framework

• Benefits of vaccinating pregnant women usually outweigh potential risks when disease exposure likelihood is high, infection would pose maternal or fetal risk, and the vaccine is unlikely to cause harm 1
• The theoretical risks of vaccination must be weighed against the documented severe morbidity and mortality from actual infections 5, 6

Common Pitfalls and Clinical Considerations

Coverage Gaps

• Current vaccination coverage remains suboptimal, with only 61.2% of pregnant women in the US receiving influenza vaccine 1, 2
• Tdap coverage increased from 13.8% to 51.0% following the 2013 recommendation but plateaued at rates similar to influenza 7

Provider Responsibilities

• Healthcare provider endorsement is the most critical factor in vaccine uptake - strong recommendations from prenatal care providers significantly increase acceptance 1
• All pregnant women should be evaluated for immunity to rubella and tested for HBsAg in every pregnancy 2
• Addressing vaccine hesitancy through education about maternal and infant benefits is essential 1, 2
• Barriers to healthcare access must be addressed for marginalized populations, including migrant communities 1

Timing Errors to Avoid

• Do not delay influenza vaccination to a specific trimester - it can and should be given at any time during pregnancy 1
• Do not miss the 27-36 week window for Tdap - this timing optimizes passive antibody transfer to the infant 2
• Do not assume prior Tdap vaccination eliminates the need for vaccination in the current pregnancy - it is recommended with every pregnancy 1, 2