Abstract:
Objective : to determine the presence of anti-SARS-CoV-2
antibodies in colostrum and mature milk in women who had SARS-CoV-2
infection during pregnancy or at delivery; to investigate the
correlation between anti-SARS-CoV-2 antibodies in milk with antibody in
maternal blood, severity of infection and time-interval from active
illness; and to evaluate immunoglobulin evolution from colostrum to
mature milk.
Design : prospective cohort-study
Setting : six hospitals in Spain and Hong-Kong.
Sample : pregnant women with confirmed SARS-CoV-2 infection
during pregnancy or at delivery.
Methods : Colostrum and mature milk were collected by
manual expression with strict contact precautions. Colostrum samples
were tested with rRT-PCR-SARS-CoV-2 and both, maternal milk and serum
were tested against SARS-CoV-2 specific immunoglobulin M, A and G
reactive to receptor binding domain of SARS-CoV-2 spike protein-1.
Results : All rRT-PCR-SARS-CoV-2 tested negative. IgA and
IgG were present in 111/135 (82.2%) and 2/135 (1.5%) colostrum samples
and 27/81 (33.3%) and 0/81 mature milk samples, respectively.
Concentrations of immunoglobulins were not associated with the timing of
infection but women with SARS-CoV-2 pneumonia had higher levels of IgA
and IgG in colostrum than those who were asymptomatic or had mild
symptoms.
Conclusion: No SARS-CoV-2 virus was found in human milk,
however, high levels of antibodies were found in colostrum, specially
IgA, irrespective of the time of infection. All women should be
encouraged to breastfeed, undertaking strict contact precautions when
there is active disease.
Funding : Spanish Government grant (Instituto de Salud
Carlos III: COV20/00188). Synlab Diagnostics’ Globales (Madrid, Spain).
Perkin Elmer.