The World Health Organization on Friday changed its orientation to pregnant women considering a Covid-19 vaccine, abandoning opposition to immunization for most pregnant women, unless they were at high risk.
The change came as a result of a protest to the previous WHO stance, which stated that the organization “did not recommend vaccinating pregnant women” with vaccines from Pfizer-BioNTech and Moderna.
Several experts expressed disappointment on Thursday at WHO’s previous position. Experts noted that this was inconsistent with guidance on the same subject from the United States Centers for Disease Control and Prevention and would confuse pregnant women seeking clear advice.
The vaccines manufactured by Pfizer-BioNTech and Moderna, although not tested on pregnant women, have not shown any harmful effects in animal studies. And the technology used in vaccines is generally known to be safe, experts said.
The new WHO phrase reflects this information:
“Based on what we know about this type of vaccine, we have no specific reason to believe that there will be specific risks that would outweigh the benefits of vaccination for pregnant women.” The recommendation is now closely aligned with the CDC’s position.
Experts praised the change, welcoming the agreement between the world’s leading public health organizations on this important issue.
“I was delighted to see that WHO changed its guidelines on offering Covid-19 vaccine to pregnant women,” said Dr. Denise Jamieson, an obstetrician at Emory University and a member of the Covid expert group at the American College of Obstetrics and Gynecology. The association was among the many women’s health organizations that urged Pfizer and Moderna to speed up vaccine testing on pregnant women.
“WHO’s most lenient language offers an important opportunity for pregnant women to be vaccinated and to protect themselves from the serious risks of Covid-19,” said Dr. Jamieson. “This impressively quick WHO review is good news for pregnant women and their babies.”
Pregnant women have traditionally been excluded from clinical trials, leaving a dearth of scientific data on the safety of medicines and vaccines in women and the fetus. Vaccines are generally considered safe and pregnant women have been urged to immunize themselves against influenza and other illnesses since the 1960s, even in the absence of rigorous clinical tests to test them.
Pfizer will test its vaccine on pregnant women in the coming months, according to a company spokesman. And Moderna plans to establish a registry to observe side effects in women who have been immunized with their vaccine.