Scientists recently conducted a study that demonstrates that pregnant women have different T-follicular helper (Thf) cell expansion according to their trimester, which affects the effectiveness of the influenza vaccine.
The researchers will present their study at the Society for Maternal-Fetal Medicine’s annual conference, called The Pregnancy Meeting.
Officials at the Centers for Disease Control and Prevention (CDC) recommend that the influenza vaccine be administered to all pregnant women who have not received vaccinations within the last year. The officials maintain their recommendations no matter the trimester of the pregnant women.
The study involved 36 pregnant women throughout the 2012 and 2014 flu seasons. The women received inactivated influenza vaccines. The researchers collected blood samples before the vaccination and 14 days afterward, showing the Thf cell response was different depending on the trimester of the pregnancy.
The scientists discovered that the vaccine’s impact on the Thf cells is more significant during a pregnant women’s first trimester.
"The study results suggest that immunological changes during pregnancy may affect the response to the vaccination," Dr. Emily Patel, a researcher at Duke University, said. "Future studies will lead to a better understanding of vaccine immunology and how pregnant women respond to antigen exposure through the course of their pregnancy.”