Cohort 1
Cohort 1 consists of 23 symptomatic women, ten of whom were confirmed to
be SARS-CoV-2 infected via RT-PCR (Table S1). Antibody testing for IgG
and IgM anti SARS-CoV-2 was conducted at various points during
convalescence from day 0 to day 66 following a positive swab result.
Anti-SARS-CoV-2 IgG antibodies were detected in 50% (5/10) of the
RT-PCR positive SARS-CoV-2 women using the Roche and Abbot Architect
platforms. Anti-SARS-CoV-2 IgM was detectable in seven women in the
symptomatic cohort, one of whom was both RT-PCR negative on
nasopharyngeal swab and IgG negative in serum (Supplementary table S3b).
However, in view of this, it is possible that this may more likely
reflect a false positive IgM. One woman did not mount an antibody
response, when tested at day 10. She described very mild symptoms,
presenting with an uncomplicated pyrexia and no respiratory symptoms.
The earliest evidence of a maternal IgG and IgM antibody response after
a positive nasopharyngeal swab was at day 0. However, this patient
reported first onset of symptoms 14 days prior to her nasal RT-PCR
testing (patient c19-13, Figure 1). Therefore, we determined that the
that the earliest response between swab positive (at symptom onset) and
a demonstrably IgG antibody response was at day 4 (Patient c19-12,
figure 1). Detectable antibody levels were not present in women tested
at day 37 and 66 post a positive nasopharyngeal swab (Supplementary
table S1).