SAN DIEGO (CNS) – Researchers at UC San Diego have found that breastfeeding mothers who received the Pfizer-BioNTech or Moderna COVID-19 vaccine had the same symptoms that were previously reported in women who are not breastfeeding, without serious side effects in their infants, it was announced Wednesday.

In December 2020, two SARS-CoV-2 messenger RNA vaccines received emergency use authorization from the United States Food and Drug Administration; however, the first trials excluded breastfeeding women, which raised questions about their safety in this specific population.

“The first concern of a mother is the safety of her child,” said Dr. Christina Chambers, professor of pediatrics at UCSD School of Medicine and professor at the Herbert Wertheim School of Public Health and Human Longevity Science. “Our study, along with previous research, suggests that Pfizer and Moderna vaccines are not red flags for nursing mothers and their infants.”

In the study, published in the online edition of Breastfeeding Medicine, researchers found that more than 85% of 180 breastfeeding women who received a COVID-19 mRNA vaccine reported temporary localized symptoms, such as pain. , redness, swelling or itching at the injection site. and systemic side effects, including chills, muscle / body pain, fever and vomiting, with higher frequency after the second dose.

In addition, after the second dose of the vaccine, women who received Moderna brand were much more likely to report symptoms. A small proportion of women after the first dose of either vaccine reported reduced milk production, and many more women reported reduced milk production after the second dose of Moderna.

“We want to emphasize that the reduction in milk production was in a small subset of women and came back completely within 72 hours of vaccination,” Chambers said. “We also cannot be sure that the reduction in supply was a side effect of the vaccine or some other unknown factor.

“What we do know is that the vaccine is incredibly effective in providing protection against COVID-19, which has proven to be a devastating and serious virus with possible long-term side effects,” he said. she declared.

Irritability and sleep deprivation have been reported in some breastfed children, but no serious adverse events have been reported.

“We know the many benefits of breastfeeding. Breast milk provides an abundance of nutritional components for infants that provide many health benefits, from strengthening the immune system to lowering rates of obesity and other conditions. and disease, ”Chambers said.

“Our results should encourage breastfeeding women to get vaccinated against COVID-19 and to continue breastfeeding their infants,” she said. “They don’t have to choose one over the other. Both are essential.”

The women recruited for the study enrolled in UCSD’s Mommy’s Milk Human Milk Research Biorepository, which strives to understand the many benefits that breast milk offers at the molecular level and uses these findings to improve health and development. of all children.

“This study would not be possible without the tremendous support of our staff and students, as well as women across the country who were willing to register and provide breast milk samples,” said Kerri Bertrand, First author of the study and research director of the biodepot. . “Together, we are finding saving, evidence-based answers to the crucial questions that arose when the pandemic first struck.”

The researchers noted that one of the limitations of the study was that post-vaccination symptoms were self-reported and suggested that further studies would be needed to see if the results can be generalized to a larger population.