The Coronavirus Vaccines and Breastfeeding

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The Coronavirus Vaccines

Before I discuss the Coronavirus Vaccine, it is useful to understand what happens in our bodies when we get an infection.

When a virus invades our bodies, it begins to attack and multiply. Our blood contains various types of white blood cells that are there to attack back. However, when a virus is new to the body, our white blood cells can become overwhelmed and may take some time to work out what this virus is and how to defeat it. This can take days or weeks, and we will feel very unwell while the virus is multiplying.

Once our bodies learn how to fight the virus, that knowledge is stored in our cells (think of a mini filing cabinet in our cells full of various battle plans).  If we are exposed to that virus again, we will know immediately how to fight it.

Simply put…vaccines give our bodies the battle plans before the battle begins!!

Our cells fighting back

Currently there are 3 main types of Covid-19 Vaccines (there will be more). None of these use the Live Covid -19 virus within them, which is why we need 2 shots with 2 of the vaccines (Pfizer/BioNTech, and Moderna, which we are currently using in Ireland). The first injection lays the foundations of immunity and the second shot gets the most protection from the vaccine.

According to the HSE (HSE 2021), for the “vaccine to work it takes:

  • 7 days after the second dose, if you got the Pfizer/BioNTech vaccine
  • 14 days after the second dose, if you got the Moderna vaccine”

“The current evidence is that the vaccine protects 95% of people who get it.” (HSE 2021)

Covid-19 vaccine

According to the HSE (2021) and the Infant Risk Center (2020), there is no reason to presume that these vaccines will be a problem for breastfeeding women or their babies. Evan if some of the weakened vaccine gets into breastmilk, it should not be a problem for the baby, as their tummy’s will digest the proteins as normal. The baby may even gain a small amount of maternal immunity. Obviously, until there is widespread vaccination, clinical trials cannot be performed to assess its effects.

If you are pregnant or breastfeeding and want to know more, please visit:

If you want to know more about how vaccines work in general and if other vaccines are safe while breastfeeding see


Our World flourishing

Centers of Disease Control and Prevention (2021). Understanding how COVID-19 vaccines work. [Accessed on 22nd Jan 2021].

Infant Risk Center (2020). COVID-19 Vaccine in Pregnancy and Breastfeeding. [Accessed on 22nd Jan 2021].

HSE (2021). Immunity after the COVID-19 Vaccine. [Accessed Online on 22nd Jan 2021].