Prior presumed coronavirus infection reduces COVID-19 risk: A cohort study

Abstract

Background Immunological cross-reactivity between common cold coronaviruses (CCC) and SARS-CoV-2 might account for the reduced incidence of COVID-19 in children. Evidence to support speculation includes in vitro evidence for humoral and cellular cross-reactivity with SARS-CoV-2 in specimens obtained before the pandemic started. Method We used retrospective health insurance enrollment records, claims, and laboratory results to assemble a cohort of 869,236 insured individuals who had a PCR test for SARS-CoV-2. We estimated the effects of having clinical encounters for various diagnostic categories in the year preceding the study period on the risk of a positive test result. Findings After adjusting for age, gender and care seeking behavior, we identified that individuals with diagnoses for common cold symptoms, including acute sinusitis, bronchitis, or pharyngitis in the preceding year had a lower risk of testing positive for SARS-CoV-2 (OR=0.76, 95%CI=0.75, 0.77). No reduction in the odds of a positive test for SARS-CoV-2 was seen in individuals under 18 years. The reduction in odds in adults remained stable for four years but was strongest in those with recent common cold symptoms. Interpretation While this study cannot attribute this association to cross-immunity resulting from a prior CCC infection, it is one potential explanation. Regardless of the cause, the reduction in the odds of being infected by SARS-CoV-2 among those with a recent diagnosis of common cold symptoms may have a role in shifting future COVD-19 infection patterns from endemic to episodic.

Prior SARS-CoV-2 infection is associated with protection against symptomatic reinfection

“…It has been recently suggested that prior exposure to seasonal coronaviruses might confer cross-protection against SARS-CoV-2. 1 Whether SARS-CoV-2 infection itself confers immunity to reinfection has not been established. Immunity is probable, at least in the short term, because reinfections are infrequently reported, despite over 55 million primary infections occurring worldwide since December 2019.…”

Differential T cell reactivity to seasonal coronaviruses and SARS-CoV-2 in community and health care workers

“…It is also possible that CD8 + T cells might mediate or contribute to rapid termination of infection as described for SARS-CoV ( 56 , 57 ) and other viral infection diseases ( 58 – 61 ). More recently, two studies reported that prior presumed CCC infections are associated with lower severity and reduced risk of COVID-19 disease ( 30 , 62 ).…”

Early cross-coronavirus reactive signatures of protective humoral immunity against COVID-19

“…Fig 3) (13,22,(36)(37)(38), point to the possibility of either remarkably rapid maturation of the humoral immune response, or the potential expansion and evolution of preexisting cross-coronavirus immunity. While common coronaviruses (cCoV) circulate annually, giving rise to broad population level seroprevalence, conflicting data have emerged related to seroprevalence of cCoV-specific immunity among individuals with distinct disease trajectories (39)(40)(41)(42)(43)(44)(45)(46). Given the significant prevalence of β-coronavirus OC43 in the USA (47), we profiled the prevalence of OC43 specific-immunity across the groups.…”