Covid-19 — Implications for the Health Care System
Unknown authors
Abstract
domain antibodies, a finding that is in agreement with other reports, 3,4 and apparently have more stable levels (Fig. 1B), although this latter finding requires further confirmation.In response to Bölke et al., their few longitudinal IgG data points mostly show rising antibodies up to day 50, followed by a decline that is compatible with our findings.The study by Wang et al. 5 to which they refer assessed antibody levels with the use of optical-density measurements for less than 43 days after symptom onset, possibly missing later decay.Thus, these findings do not refute our results.Finally, very recent reports of well-documented cases of SARS-CoV-2 reinfection appear to validate our concerns that declining antibody levels may reflect waning immunity.In the context of our findings, these reports also raise questions about the likelihood of natural herd immunity.Whether a vaccine can give more prolonged responses to promote herd immunity remains to be determined.