In:
Open Forum Infectious Diseases, Oxford University Press (OUP)
Abstract:
Virologic determinants of seroconversion to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were defined in a post-hoc analysis of prospectively studied vaccine and infection-naïve individuals at high risk for coronavirus disease 2019 (COVID-19). Methods This phase 3 COVID-19 prevention trial (NCT04452318) with casirivimab and imdevimab was conducted in July 2020–February 2021, prior to widespread vaccine availability. Placebo-treated participants who were uninfected (SARS-CoV-2 quantitative reverse transcription polymerase chain reaction [RT-qPCR] negative) and seronegative were assessed weekly for 28 days (efficacy assessment period [EAP] ) for COVID-19 symptoms and SARS CoV-2 infection by RT-qPCR of nasopharyngeal swab samples, and for serostatus by anti-nucleocapsid immunoglobulin (Ig) G. Regression-based modeling, including causal mediation analysis, estimated the effects of viral load on seroconversion. Results Of 157/1069 (14.7%) uninfected and seronegative (for anti-spike IgG, anti-spike IgA, and anti-nucleocapsid IgG) participants who became infected during the EAP, 105 (65%) seroconverted. Mean (SD) maximum viral load of seroconverters was 7.23 (1.68) log10 copies/mL versus 4.8 (2.2) log10 copies/mL in those who remained seronegative; viral loads of ∼6.0 log10 copies/mL better predicted seroconversion. The mean of the maximum viral load was 7.11 log10 copies/mL in symptomatic versus 5.58 log10 copies/mL in asymptomatic participants. The mean duration of detectable viral load was longer in seroconverted versus seronegative participants: 3.24 versus 1.63 weeks. Conclusions Maximal SARS-CoV-2 viral load is a major driver of seroconversion and symptomatic COVID-19, with high viral loads (∼6.0 log10copies/mL) better predicting seroconversion. Serology underestimates infection rates, incidence, and prevalence of SARS CoV-2 infection.
Type of Medium:
Online Resource
ISSN:
2328-8957
DOI:
10.1093/ofid/ofad598
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2023
detail.hit.zdb_id:
2757767-3
