Influenza immunizations for IVF patients: A clinical trial at CHR

CHR is currently conducting a clinical trial that involves the administration of Influenza vaccination. All patients undergoing IVF at CHR are offered participation if they have not yet received the annually available Influenza vaccination. This is a relatively easy trial to conduct because all pregnant women and all women planning on pregnancy are now advised to have an Influenza vaccination (even in pregnancy), and all women in the trial are getting immunized. The randomization of the trial just involves short time differences between administration of the immunization.

Interestingly, only very recently on February 17, 2017 did the American College of Obstetricians and Gynecologists (ACOG) issue a new “Influenza Season Assessment and Treatment Algorithm Announcement,” which pointed out highly elevated Influenza activity across the country, which is expected to continue for a few more weeks.

Influenza immunization is now strongly recommended because, for reasons that have remained unclear, pregnant women are at increased risks from Influenza. Moreover, large safety studies of Influenza vaccine, administered during different periods of pregnancy, have found the immunization during pregnancy to be safe. Indeed, as we reviewed in these pages before, large-scale studies in different parts of the world registered significant benefits from Influenza immunization during pregnancy, in that such immunizations by up to half reduced late pregnancy complications like premature labor and preeclampsia/eclampsia.

It was the latter observation that led CHR investigators toward the currently running Influenza trial because the observation of so radically diminished late pregnancy complications led to the hypothesis that Influenza vaccination may be inducing tolerance pathways, required for normal tolerance of the fetal semi-allograft (the fetus is in 50% foreign to the mother’s immune system) by the maternal immune system. If that could be proven, Influenza vaccination may also beneficially affect IVF outcomes by improving chances of embryos to implant and, at the same time, by reducing miscarriage risks.

We, therefore, want to take this opportunity to remind all CHR’s patients that we will gladly administer Influenza (“flu”) vaccinations free of charge to anybody who so far has not been immunized. Just ask your coordinator!


This is a part of the March 2017 VOICE.