This project will compare vaccination of pregnant women with age-matched non-pregnant women and women vaccinated in the postpartum period during lactation. The primary objectives are to assess the immune responses (humoral immunity, cellular immunity, mucosal immunity) and safety after either administration of the Comirnaty COVID-19 vaccine (mRNA, Pfizer BioNtech), the COVID-19 Moderna vaccine (mRNA, Moderna), the COVID-19 vaccine Vaxzevria (Viral Vector, Astra Zeneca) or any other vaccine that will become available for the Belgian population.