What are the recommended immunizations for a patient at 28 weeks gestation?

Recommended Immunizations for Pregnant Women at 28 Weeks Gestation

At 28 weeks gestation, all pregnant women should receive the Tdap (tetanus, diphtheria, and acellular pertussis) vaccine and the inactivated influenza vaccine (during influenza season) to protect both mother and infant from severe disease. 1, 2

Tdap Vaccination

Timing and Administration

• Tdap should be administered between 27 and 36 weeks' gestation (optimal timing is at 27-28 weeks) 1
• This timing maximizes maternal antibody response and passive antibody transfer to the infant 1
• Tdap is recommended during EACH pregnancy, regardless of prior vaccination history 1
• Earlier vaccination within the 27-36 week window provides higher antibody concentrations in cord blood 1

Rationale

• Protects newborns against pertussis during their vulnerable first months of life before they can receive their own DTaP vaccination 1
• Maternal antibodies wane quickly, making vaccination during each pregnancy necessary 1
• Pertussis cases have increased in recent years, with highest rates of severe disease and mortality in infants under 6 months 3

Special Situations

• If a tetanus booster is indicated during pregnancy (>10 years since previous Td), Tdap should be used 1
• For pregnant women with unknown or incomplete tetanus vaccination history, Tdap should replace one dose in the recommended series 1
• If Tdap is not administered during pregnancy, it should be given immediately postpartum 1

Influenza Vaccination

Timing and Administration

• Inactivated influenza vaccine (IIV) is recommended for all pregnant women during any trimester 2, 4
• Should be administered as soon as it becomes available during influenza season (typically October to May in the US) 4

Rationale

• Pregnant women are at significantly higher risk for severe illness and complications from influenza 2, 4
• Risk of hospitalization increases as pregnancy progresses (4.7-fold increase at 37-42 weeks) 2
• Vaccination reduces risk of maternal complications, late pregnancy loss, and provides passive immunity to infants 2, 4
• An estimated 1-2 hospitalizations can be prevented for every 1,000 pregnant women vaccinated 2

Important Considerations

• Only the inactivated influenza vaccine should be used; the live attenuated influenza vaccine (nasal spray) is contraindicated during pregnancy 1, 2
• Tdap and influenza vaccines can be administered simultaneously 1

Vaccination Coverage and Implementation

Current Coverage

• Despite recommendations, vaccination rates remain suboptimal:
  • Tdap: increased from 13.8% (2013) to 51.0% (2014) 5
  • Influenza: approximately 49.4% during peak influenza season 5, 6

Improving Uptake

• Provider recommendation is the most influential factor in vaccination acceptance (75.2% for influenza and 72.7% for Tdap) 2
• Common reasons for declining vaccination include concerns about vaccine effectiveness and lack of knowledge about the need for Tdap during every pregnancy 6

Other Vaccines During Pregnancy

Generally Safe in Pregnancy (if indicated)

• Hepatitis B vaccine (for women at risk) 2
• Pneumococcal vaccine (for women with increased risk) 2
• Meningococcal vaccine (for high-risk situations) 2
• Inactivated poliovirus vaccine (if indicated) 2

Contraindicated During Pregnancy

• Live attenuated vaccines (MMR, varicella, live attenuated influenza) 1, 2

Clinical Pearls

• Document vaccination status at the first prenatal visit
• Emphasize that maternal vaccination protects both mother and infant
• Vaccination is especially important for women with underlying medical conditions
• Maternal antibodies provide protection to infants during their most vulnerable period before they can receive their own vaccinations
• The benefits of vaccination during pregnancy far outweigh theoretical risks