Immune response following infection with SARS-CoV-2 and other coronaviruses: A rapid review

Abstract

In this review, we systematically searched and summarized the evidence on the immune response and reinfection rate following SARS-CoV-2 infection. We also retrieved studies on SARS-CoV and MERS-CoV to assess the long-term duration of antibody responses. A protocol based on Cochrane rapid review methodology was adhered to and databases were searched from 1/1/2000 until 26/5/2020. Of 4744 citations retrieved, 102 studies met our inclusion criteria. Seventy-four studies were retrieved on SARS-CoV-2. While the rate and timing of IgM and IgG seroconversion were inconsistent across studies, most seroconverted for IgG within 2 weeks and 100% (N = 62) within 4 weeks. IgG was still detected at the end of follow-up (49-65 days) in all patients (N = 24). Neutralizing antibodies were detected in 92%-100% of patients (up to 53 days). It is not clear if reinfection with SARS-CoV-2 is possible, with studies more suggestive of intermittent detection of residual RNA. Twenty-five studies were retrieved on SARS-CoV. In general, SARS-CoV-specific IgG was maintained for 1-2 years post-infection and declined thereafter, although one study detected IgG up to 12 years post-infection. Neutralizing antibodies were detected up to 17 years in another study. Three studies on MERS-CoV reported that IgG may be detected up to 2 years. In conclusion, limited early data suggest that most patients seroconvert for SARS-CoV-2-specific IgG within 2 weeks. While the long-term duration of antibody responses is unknown, evidence from SARS-CoV studies suggest SARS-CoV-specific IgG is sustained for 1-2 years and declines thereafter.

Keywords: COVID-19; MERS-CoV; SARS-CoV; SARS-CoV-2; seasonal coronaviruses.

FIGURE 1

SARS‐CoV‐2‐specific IgM seropositivity rate at three time points is displayed (1‐7 days, 8‐14 days and ≥14 days). Note: Zhang 2020c collected data at following time points: <10 days, 10‐20 days and 20‐30 days

FIGURE 2

SARS‐CoV‐2‐specific IgG seropositivity rate at three time points is displayed (1‐7 days, 8‐14 days and ≥ 14 days). Note: Zhang 2020c collected data at following time points: <10 days, 10‐20 days and 20‐30 days

FIGURE 3

Solid line gives mean estimate of SARS‐CoV‐specific IgG seropositivity rate and shaded area gives 95% CI at each time point (1 week, 1 month, 3 months, 4‐6 months, 1 year, 2 years and 3 years post‐infection) by random effects meta‐analysis (N = 614 participants; studies included: Cao 2007, Chang 2005, He 2004, Huang 2005, Li 2003, Liu 2006, Mo 2006, Shi 2004, Tang 2011, Wu 2007a, Wu 2007b, Yang 2009)

FIGURE 4

Quality assessment for all included studies presented (n = 102); numbers on bars indicate number of studies that were answered yes/no/unclear/not applicable for each domain. The same risk of bias tool was used across all designs due to the lack of clarity in some studies regarding the distinction between cohorts and case series. For the purposes of this assessment, all were considered as case reports/case series. The generalizability of studies was often unclear due to the testing platforms used that are not widely available and healthcare systems and practices that are country‐specific