NEW YORK (AP) – US drugmaker Pfizer and its German partner BioNTech on Thursday began a study to be conducted in nine countries on the effects of its coronavirus vaccine on pregnant women.
The companies said the first inoculations have already been administered for the study, which is expected to involve 4,000 pregnant women aged 18 and over with 24 to 34 weeks’ gestation. Some will receive both doses of the vaccine and others will receive placebos, three weeks apart.
The volunteers will be followed for between seven and 10 months, depending on whether they received the vaccine or the placebo, to assess how effective and safe the vaccine is in pregnant women. Among the participants there will be women from the United States, Canada, Argentina, Brazil, Chile, Mozambique, South Africa, Spain and Great Britain.
“Pregnant women are at increased risk of complications and severe symptoms from COVID-19,” said Dr. William Gruber, director of vaccine research and clinical development at Pfizer, in a statement. “It is essential that we develop a vaccine that is safe and effective” for them.
Pregnant women were excluded from previous studies of the vaccine, which has been licensed for emergency use in the United States, the European Union and other countries.
After the babies are born, the women who were given the placebo will receive the actual vaccine.
The study will evaluate the effects in infants for approximately six months, to review the safety of the vaccine and whether they received possible antibodies that protect them from the virus from their mothers.
The companies plan this year to begin testing the vaccine in children, ages 5 to 11, and under 5 years of age, and review the effects of their vaccine in people with weakened immune systems. The results of their study are currently being reviewed in children from 12 to 15 years old.