The researchers in the U.S. studied about the composition of antibodies in the breast milk following vaccination by Pfizer-BioNTech, Moderna, or Johnson & Johnson vaccines.
The onset of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has changed the global healthcare structure with the surge of infectivity rate and deaths worldwide. Researchers and scientists continued their intensive effort to develop vaccines against the virus. The U.S. Food and Drug Administration (FDA) and World Health Organization (WHO) in December 2020 authorized the emergency use of Pfizer-BioNTech vaccine in 16 years of age or older individuals in order to prevent COVID-19. This vaccine is the first of its kind to receive emergency validation from the WHO and the U.S. FDA. This vaccine includes new messenger RNA (mRNA) and can induce spike protein or S-protein specific neutralizing antibodies. Moreover, Moderna mRNA vaccine and the Johnson & Johnson human adenovirus vaccine were also approved shortly in the U.S. by the U.S.FDA. In this context, it is important to mention that approximately 188 million people in the U.S. have already received at least one dose of the vaccine as of July 27, 2021. In the current study, researchers in the U.S. studied the samples of 50 different lactating mothers which is collected one week before, and 14 or 28 days after the second dose of any of the three vaccines such as Pfizer-BioNTech, Moderna, and Johnson & Johnson (J&J). The researchers noted that none of the samples had a history of SARS-CoV-2 infection, nor did any milk sample contain SARS-CoV-2-specific immunoglobulin G before vaccination. Moreover, natural infection caused by the virus or vaccination of the mother leads to secretion of SARS-CoV-2 antibodies in the breast milk, which provides passive immunity to the child.
The researchers found that the average specific milk IgG levels were same in both Pfizer-BioNTech vaccine and Moderna vaccine, but it is lower in J&J vaccine. They found that the antibody titer values are higher in those samples vaccinated with Moderna.