Long‐term coexistence of SARS‐CoV‐2 with antibody response in COVID‐19 patients

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection causing coronavirus disease 2019 (COVID‐19) has spread worldwide. Whether antibodies are important for the adaptive immune responses against SARS‐CoV‐2 infection needs to be determined. Here, 26 cases of COVID‐19 in Jinan, China, were examined and shown to be mild or with common clinical symptoms, and no case of severe symptoms was found among these patients. Strikingly, a subset of these patients had SARS‐CoV‐2 and virus‐specific IgG coexist for an unexpectedly long time, with two cases for up to 50 days. One COVID‐19 patient who did not produce any SARS‐CoV‐2–bound IgG successfully cleared SARS‐CoV‐2 after 46 days of illness, revealing that without antibody‐mediated adaptive immunity, innate immunity alone may still be powerful enough to eliminate SARS‐CoV‐2. This report may provide a basis for further analysis of both innate and adaptive immunity in SARS‐CoV‐2 clearance, especially in nonsevere cases.

Clinical performance of different SARS‐CoV‐2 IgG antibody tests

“…The titer needed for potential protective immunity is not yet (officially) defined. In one study, it is reported, that an individual cleared SARS‐CoV‐2 without developing antibodies up to 46 days after illness 9 . The mechanism of immunity, especially of protective immunity (if applicable) and how long it will last, needs to be further investigated.…”

Successful simultaneous pancreas and kidney transplant in a patient post–COVID-19 infection

“…There have been reports of prolonged coexistence of anti-SARS-CoV-2 IgG along with the positive reverse transcriptase-PCR for SARS-CoV-2, raising the possibility of variable level of immunity provided by the antibodies. 7 In a smaller study conducted by Zhang et al, 8 both IgM and IgG antibodies were detected in all 39 patients infected with SARS-CoV-2 after 5 days of disease onset. In a report of 149 convalescent individuals with COVID-19 who recovered, authors found that most convalescent plasmas collected an average of 39 days after the onset of symptoms do not contain high levels of neutralizing activity.…”

COVID‐19 diagnostic testing: Technology perspective

“…The results show that the seroprevalence increased from 3.1% (95% CI: 0.2-5.99, n = 343) in the first week to 6.1% (95% CI: 2.6-9.33, n = 416) and 9.7% (95% CI: 6.1-13.11, n = 576) in the second and third weeks, respectively. 104 4) Limited understanding of viral invasion, replication, and evolution [105][106][107] . Accurate COVID-19 diagnosis and effective treatment will likely depend on better understanding the SARS-CoV-2 virus and COVID-19 pathology.…”