The study published in the JAMA Network Open examined short-term side-effects of Pfizer and Moderna COVID-19 vaccination on pregnant and breast-feeding individuals, and compared it to experiences of non-pregnant women.

This was an online based study which enrolled participants via social networks and all data collected was self-reported by the participants. More than 17,000 individuals participated in this survey, 7,809 were pregnant, 6,815 were breastfeeding and 2,901 were neither. The group were similar in terms of baseline characteristics.

The main finding was that there were no differences between the rate of minor side-effects between pregnant, breastfeeding and non-pregnant/not breastfeeding individuals. The side-effects most commonly experienced were pain at injection site (91.4%) and fatigue (31.3), with myalgia (muscle pain), headaches, chills and fever being less common. All these side-effects were observed more commonly after the second dose of the vaccine compared to the first.

The conclusions that can be drawn from this study are that minor side-effects following administration of mRNA COVID-19 vaccines are common, with pain at the injection site and fatigue being most likely to be experienced.

There is no increased risk of these side-effects for pregnant and breastfeeding individuals.

Current guidelines in Australia recommend vaccination against COVID-19 for pregnant women at any stage of pregnancy and during breastfeeding and this study supports vaccine safety in these groups.

It must also be stressed that COVID-19 infection in pregnancy is associated with an increased risk of severe clinical symptoms which may adversely affect the health of the mother and the wellbeing of the fetus.

On the other hand, there is no evidence to suggest that vaccination either during pregnancy or breastfeeding is associated with a higher risk of either long- or short-term complications, compared to the general population. The balance of risks clearly favours vaccination in these at-risk groups.