SARS-CoV-2–Specific Antibodies in Breast Milk After COVID-19 Vaccination of Breastfeeding Women | Breastfeeding | JAMA | JAMA Network
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State of Israel Ministry of Health. The COVID-19 vaccine operation launched today. State of Israel Ministry of Health; 2021. Posted December 19, 2020. Accessed February 24, 2021.
Polack  FP, Thomas  SJ, Kitchin  N,  et al; C4591001 Clinical Trial Group.  Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine.   N Engl J Med. 2020;383(27):2603-2615. doi:10.1056/NEJMoa2034577PubMedGoogle ScholarCrossref
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    3 Comments for this article
    Robert Eibl, Dr. Med. | Alumni German Cancer Research Center Association
    I found it interesting to see a robust IgA response in breast milk 2 and 4 weeks after the first vaccination into the shoulder; I wonder if there is a similar IgA response for everybody, for example in the saliva as well, which may explain the high protection and low infection rate of anyone after vaccination with Comirnaty (TM) (Pfizer/Biontech).
    IgA Antibody Against SARS-CoV-2 Variants
    Takuma Hayashi, MBBS, DMSci, GMRC, PhD. | National Hospital Organization Kyoto Medical Center
    Secretory IgA is the most abundant in the first milk secreted within the first few days after delivery. In particular, infant babies have a low ability to make IgA on their own. Therefore, IgA in breast milk is important for preventing infection with SARS-CoV-2.

    In this paper, it is found that breast milk contains a large amount of IgA and IgG against SARS-CoV-2 after the second dose of the COVID-19 vaccine. In this respect, the importance of two doses of COVID-19 vaccine was shown.

    In preliminary studies, it has already been reported that a single dose of the
    BNT162b2 vaccine markedly induces neutralized IgG activation against the B.1.1.7 variant in people previously infected with original SARS-CoV-2. However, compared to the method of antibody titers of IgM and IgG against SARS-CoV-2, the method for evaluating the antibody titer of IgA against original SARS-CoV-2 and SARS-CoV-2 variants has not yet made great progress. In particular, it is important to establish a method for evaluating the antibody titer of IgA against SARS-CoV-2 variants, which has been pointed out to have strong infectivity and a high severity rate.

    Dr. Hayashi T. and Dr. Konishi I.
    Anti-Covid Antibodies in Breast Milk
    Charles Brill, MD - Retired | Thomas Jefferson University
    Will the infants' digestive enzymes break down the antibodies?
    Research Letter
    April 12, 2021

    SARS-CoV-2–Specific Antibodies in Breast Milk After COVID-19 Vaccination of Breastfeeding Women

    Author Affiliations
    • 1Pulmonary Institute, Shamir Medical Center, Zerifin, Israel
    • 2The Center for Microbiome Research, Shamir Medical Center, Zerifin, Israel
    • 3IVF Unit, Shamir Medical Center, Zerifin, Israel
    • 4Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
    • 5Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
    JAMA. 2021;325(19):2013-2014. doi:10.1001/jama.2021.5782

    On December 20, 2020, Israel initiated a national vaccination program against COVID-19. One prioritized group was health care workers, many of whom are breastfeeding women.1 Despite the fact that the vaccine trial did not include this population2 and no other vaccine-related safety data had been published, breastfeeding women belonging to risk groups were encouraged to receive the vaccine.3 The Centers for Disease Control and Prevention has also recommended that breastfeeding women belonging to vaccine-target groups be immunized.4 We investigated whether maternal immunization results in secretion of SARS-CoV-2 antibodies into breast milk and evaluated any potential adverse events among women and their infants.