Longitudinal Molecular and Serological Evidence of SARS-CoV-2 Infections and Vaccination Status: Community-Based Surveillance Study (CONTACT)

Olga Sánchez-Soliño; Ryan D Kilpatrick; Christopher Johnson; Yixin Fang; Yizhou Ye; Negar Niki Alami; Katarzyna Zarish; Whitney S Krueger; Nancy Dreyer; Gregory C Gray

doi:10.1007/s40121-024-00923-4

Longitudinal Molecular and Serological Evidence of SARS-CoV-2 Infections and Vaccination Status: Community-Based Surveillance Study (CONTACT)

Infect Dis Ther. 2024 Apr;13(4):633-645. doi: 10.1007/s40121-024-00923-4. Epub 2024 Mar 10.

Authors

Olga Sánchez-Soliño¹, Ryan D Kilpatrick², Christopher Johnson^{2

3}, Yixin Fang², Yizhou Ye², Negar Niki Alami^{2

4}, Katarzyna Zarish², Whitney S Krueger², Nancy Dreyer^{5

6}, Gregory C Gray⁷

Affiliations

¹ AbbVie Inc., 26525 Riverwoods Blvd., Mettawa, North Chicago, IL, 60045, USA. olga.sanchez@abbvie.com.
² AbbVie Inc., North Chicago, IL, USA.
³ Amgen, Thousand Oaks, USA.
⁴ Pfizer, New York, USA.
⁵ IQVIA Real World Solutions, Cambridge, MA, USA.
⁶ Dreyer Strategies, Newton, USA.
⁷ Division of Infectious Diseases, School of Medicine, University of Texas Medical Branch, Galveston, TX, USA.

Abstract

Introduction: This prospective, longitudinal, community-based study, EpidemiologiCal POpulatioN STudy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Lake CounTy, Illinois (CONTACT), investigated coronavirus disease 2019 (COVID-19) immunity, occupational risks related to SARS-CoV-2 exposure, and long-term immunoglobulin G (IgG) seroconversion kinetics.

Methods: At baseline and follow up (3, 6, and 9 months), non-hospitalized adult participants provided nasal and blood serum specimens for molecular [reverse transcription polymerase chain reaction (RT-PCR)] and serological (IgG) testing (4 November 2020-30 October 2021).

Results: At baseline, 6.4% (65/1008) had evidence of current/prior SARS-CoV-2 infection. At 3, 6, and 9 months, positive PCR tests were obtained from 0.4% (3/781), 0.4% (3/733), and 0% (0/673) of participants, respectively. Positive IgG occurred at baseline and 3, 6, and 9 months in 4.5% (45/1008), 6.0% (48/799), 5.4% (39/733), and 2.8% (19/673) of participants, respectively. Of participants positive for IgG at baseline, 28 had a negative IgG test at a follow-up visit; of those 28, 21 had their first negative IgG test within 6 months. Participants were more likely to retain positive IgG if they were 18-29 years of age, were male, or had medium-high/high-risk occupations. A high vaccination rate (70% received ≥ 1 dose by 9 months) was observed. Influence of occupational status or characteristics on transmission and IgG, and COVID-19 vaccination trends, are shown.

Conclusions: This study expands on prior studies assessing COVID-19 immunity and IgG seroconversion by including both RT-PCR and serologic testing and longitudinal follow-up of study participants. We observed decreased infection rates over the 9 month follow-up period as well as a decline in IgG persistency after 6 months. The findings from this community-based study regarding vaccinate rates, infection rates by PCR, and IgG persistency over time can help improve our understanding of COVID-19 immunity, occupational risks related to SARS-CoV-2 exposure, and the kinetics of long-term IgG seroconversion, which is important to help guide local and national mitigation strategies.

Clinical trial registration: NCT04611230.

Keywords: COVID-19; Community-based research; Epidemiology; SARS-CoV-2.

Associated data

ClinicalTrials.gov/NCT04611230