Women in the UK are now able to receive vaccinations against SARS-CoV-2, the virus that causes COVID-19 after a change in guidance by the Medicines and Healthcare products Regulatory Agency (MHRA). For women who receive a COVID-19 vaccination while donating milk to Hearts, please let the team know on the screening questionnaire, but there is no need to stop expressing for donation after receiving the vaccine.

Vaccinations are typically safe for breastfeeding women and women who donate milk don’t need to stop or delay donating after most vaccines. This is because most are made from fragments of viruses, designed to trick the body into preparing an immune response that will kick into action if they encounter the actual virus again in the future. Some vaccines are made with small doses of live virus, not enough to cause illness, but enough to help train the immune response to respond to an infectious dose. For live vaccines such as yellow fever, mothers are asked to stop donating milk for 28 days after their vaccination as a precaution.

Two COVID-19 vaccines are now in use in the UK. The Oxford vaccine produced by AstraZeneca uses a standard technology for producing vaccines, wrapping up a fragment of SARS-CoV-2 in another virus, which itself cannot reproduce and is therefore harmless to the recipient. The Pfizer vaccine using a short fragment of messenger RNA, the recipe that tells cells how to make a fragment of the SARS-CoV-2 virus, wrapped up in a liposome – a tiny package made of nano-scale fatty acids.

There is no evidence that either vaccine would reach the breast and enter the milk, and even if small quantities of the vaccine did, there is no plausible mechanism by which this could cause harm. Neither vaccine is live, and therefore there is no evidence that milk donors should stop or delay donating milk after vaccination.

Therefore, after consulting with our expert advisors, scientists, doctors and other milk bank leaders from around the world, we conclude women will be able to donate milk to the Hearts Milk Bank as normal after vaccination for COVID-19.

There may also be benefits to receiving milk donated after vaccination, with antibodies produced that could get into milk and therefore help protect vulnerable infants. Our team at the Hearts Milk Bank is actively supporting plans for research to understand more about this, and we will keep you posted.