Short-term reactions among pregnant and lactating individuals in the first wave of the COVID-19 vaccine rollout

Author(s): Kachikis A, Englund JA, Singleton M et al

Short-term reactions among pregnant and lactating individuals in the first wave of the COVID-19 vaccine rollout - article image

JAMA Netw Open Published online 17 August, 2021 |

Digest author(s): Stylianos Loukides, e-Learning Director / 21 August, 2021

One of the most susceptible populations to potentially severe COVID-19 infection is pregnant women. The successful production of effective vaccines provides the possibility of protecting the population against SARS-CoV-2, however there was scepticism about the safety of vaccination of pregnant women, as they were not included in the preliminary clinical studies. Furthermore, limited data exist for SARS-CoV-2 vaccines and lactation. The current study aimed to determine outcomes of both pregnant and lactating individuals after receiving COVID-19 vaccines.

The study was mainly based on a prospective online cohort of 7809 pregnant women, 6815 nursing women, and 2091 women who intended to become pregnant within a short period of time from the first dose of the vaccine.

61.9% were vaccinated with the mRNA vaccine of the company Pfizer and 37.8% with the vaccine of the company Moderna, while 89.9% of women completed both doses. 97% reported any action after the first dose, the most common being pain at the injection site (91.4%) and the second being fatigue (31.3%). The frequency of reactions was higher with the second dose, but in total only 100 people (0.6%) sought medical help after the first dose, including 50 pregnant women, and 221 women (1.3%) after the second dose, including 156 pregnant women. Among the 7809 pregnant women reported obstetric problems, a total of 346 women (4.4%) after the first dose, and 484 (7.5%) after the second.

A total of 6586 (84.3%) pregnant women had received both doses at the time of analysis of the data. Of these, 6244 (94.8%) were still pregnant, 288 (4.4%) had given birth, and 49 (0.7%) reported miscarriages in the phase of the second dose of the vaccine. Among women who breastfed, 155 women (2.3%) reported discontinuation of breastfeeding after the first dose and 130 (2.1%) after the second. Reduced milk production for less than 24 hours reported 339 women (5%) after the first and 434 (7.2%) after the second dose.

This large prospective cohort study found that COVID-19 vaccines were well-tolerated among individuals who were pregnant, lactating, or planning pregnancy. Any reported reaction is considered as limited. The additive effect of the current study was the vaccine safety for lactating individuals. This is somehow important since it provides protection during a a non-chronically specified period.

General respiratory patient care
Public health
Respiratory digests
Respiratory infections