Vaccination in twin pregnancies: comparison between immunization before conception and during pregnancy

Area of Science:

• Immunology
• Obstetrics
• Infectious Diseases

Background:

• Assessing the impact of COVID-19 vaccination timing on maternal and fetal health is crucial, especially in high-risk pregnancies like twin gestations.
• Understanding the development of neutralizing Anti-Spike Protein IgG (Anti-S-IgG) antibodies is key to evaluating vaccine effectiveness during pregnancy.
• Previous studies have explored vaccine responses in singleton pregnancies, but data specific to twin pregnancies remains limited.

Purpose of the Study:

• To compare the development of neutralizing Anti-Spike Protein IgG (Anti-S-IgG) levels in twin pregnancies based on vaccination timing: before conception versus during pregnancy.
• To evaluate the association between vaccination timing, COVID-19 infection, and Anti-S-IgG levels in twin pregnancies.
• To provide evidence-based recommendations for optimal COVID-19 vaccination strategies in women with twin pregnancies.

Main Methods:

• A prospective study involving 83 women with twin pregnancies, categorized by vaccination status (pre-conception, during pregnancy, or unvaccinated).
• Collection of three blood samples for anti-S-IgG immunodiagnostics.
• Review of electronic medical records for vaccination history, PCR test results, and clinical outcomes; age-matched non-pregnant women served as controls.

Main Results:

• Women vaccinated before conception exhibited significantly higher neutralizing Anti-S-IgG levels in the 3rd trimester compared to those vaccinated during pregnancy, irrespective of COVID-19 infection status.
• Unvaccinated pregnant women who contracted COVID-19 experienced severe illness, while vaccinated women (pre-conception or during pregnancy) had only mild symptoms.
• Infection before conception was linked to lower Anti-S-IgG levels during pregnancy, whereas infection during pregnancy resulted in high antibody levels, particularly in those vaccinated pre-conception.

Conclusions:

• A full course of COVID-19 vaccination prior to conception is recommended for twin pregnancies to ensure robust and sustained antibody protection.
• Vaccination during pregnancy resulted in lower neutralizing antibody levels and a faster decline compared to pre-conception vaccination in twin pregnancies.
• Pre-conception vaccination appears to provide superior protection against severe COVID-19 outcomes in twin pregnancies.