Table 3 Summary of evidence about antibodies
From: Recommendations for breastfeeding during Coronavirus Disease 2019 (COVID-19) pandemic
Authors | Study country | Sample size | Milk samples | Time of breast milk collection | Detection results | Titers | Detection methods | Infection status |
|---|---|---|---|---|---|---|---|---|
Demers-Mathieu et al. [66] | USA | 27 | 27 | Collected during lactation time between 4 and 10 months | S2 SARS-CoV-2-specific IgG level was higher in the COVID-19 group than in the control group | NA | ELISA | 7 confirmed, 20 suspected |
Fenizia et al. [40] | Italy | 10 | 10 | Collected 5 days after delivery, tested SARS-CoV-2 positive during the third trimester | One sample positive for IgM | NA | CLIA | Confirmed, symptomatic |
Fox et al. [67] | USA | 15 | 15 | 3–4 weeks after symptoms abated | 80% positive for IgA and 67% positive for IgG and/or IgM | All endpoint titers significantly higher than control samples, 10–104 | ELISA | 8 confirmed, recovered and 7 suspected |
Gao et al. [22] | China | 14 | 14 | Collected within 7 days after delivery | 3 positive for IgG or IgM | IgG: 103.15–145.31 AU/ml IgM: 19.86–92.01 AU/ml | CLIA | Confirmed, symptomatic |
Lebrao et al. [68] | Brazil | 1 | 2 | On the 3rd day after delivery and the 6th day since the onset of symptoms | Both positive for IgA | 2.5 (3rd day after delivery) and 1.9 (the 6th day since the onset of symptoms) | ELISA | Confirmed, symptomatic |
Pace et al. [49] | USA | 18 | 37 | 12.0 ± 8.9 days after the onset of symptoms | 76% positive for IgA and 80% positive for IgG | Antibody concentration of samples from infected mothers higher than antibody concentration of milk samples collected before the pandemic | ELISA | Confirmed, 15 symptomatic and 3 asymptomatic |
Peng et al. [50] | China | 15 | 38 | Collected at 10 time points: the day of delivery, the 3rd, 7th, 14th, 21st, 28th, 35th, 42nd, 56th and 70th day after delivery | 21 positive for IgM | 0.1–3.03 | ELISA | Confirmed, symptomatic |
van Keulen et al. [69] | Netherlands | 38 | 38 | Approximately 6 days after the onset of symptoms | 83% confirmed cases and 67% suspected cases positive for IgA | NA | ELISA | 29 confirmed and 9 suspected |
Yu et al. [58] | China | 1 | 2 | Collected on the 11th and 27th after the onset of symptoms | Both positive for IgG | NA | ELISA | Confirmed, symptomatic |