No serious Covid vaccine side effects in breastfeeding moms, infants: Study

Los Angeles: Breastfeeding mothers vaccinated with Pfizer or Moderna preventive experienced similar side effects to what have previously been reported in non-breastfeeding women, while infants exhibited no adverse events after immunisation, a study has found.

The research, published in the journal Breastfeeding Medicine, involved 180 breastfeeding women who received both doses of either the Pfizer-BioNTech or Moderna vaccine.

Over 85 per cent of the participants reported temporary localised symptoms, such as pain, redness, swelling or itching at the injection site, and systemic side effects, including chills, muscle or body aches, fever and vomiting, with higher frequency following the second dose.

“A mother’s first concern is the safety of her child,” said Christina Chambers, a professor at the University of California (UC) San Diego School of Medicine in the US.

“Our study, along with previous research, suggests the Pfizer and Moderna vaccines are not red flags for breastfeeding mothers and their infants,” Chambers said.

Following the second dose, women who received the Moderna vaccine were significantly more likely to report symptoms, according to the researchers.

A small proportion of women following the first dose of either vaccine brand reported a reduction in milk supply, and significantly more women reported a reduction in milk supply following the second dose of Moderna, they said.

“We want to emphasise that the reduction in milk supply was in a small subset of women and came back fully within 72 hours after vaccination. We also cannot be certain that the supply reduction was a side effect of the vaccine or another unknown factor,” said Chambers.

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

Irritability and poor sleep were reported in some breastfed children, but no serious adverse events, the researchers said.

“We know the many benefits of breastfeeding. Breast milk provides an abundance of nutritional components to infants that provide many health benefits, from stronger immune systems to lower rates of obesity and other conditions and illnesses,” said Chambers.

“Our results should encourage lactating women to get the COVID-19 vaccine and to continue to breastfeed their infants. They do not have to choose one over the other. Both are critical,” she added.

The researchers noted that a limitation of the study was that symptoms post vaccination were self-reported and suggested additional studies will be needed to see if the findings can be generalised to a larger population.