| Title: |
Serological evaluation of coronavirus IgA and IgG antibodies in a repeated cross-sectional cohort of unvaccinated and vaccinated pregnant individuals over three months following SARS-CoV-2 infection |
| Authors: |
Guadalein Tanunliong; Ana Citlali Márquez; Hind Sbihi; Tamara Pidduck; Yin Chang; Fang Fang Li; Danielle Luk; Lucia Forward; Elisabeth McClymont; Chelsea Elwood; Mel Krajden; Agatha N. Jassem; Deborah Money; Inna Sekirov |
| Source: |
Microbiology Spectrum, Vol 14, Iss 1 (2026) |
| Publisher Information: |
American Society for Microbiology |
| Publication Year: |
2026 |
| Collection: |
Directory of Open Access Journals: DOAJ Articles |
| Subject Terms: |
vaccines; COVID-19; endemic coronavirus; pregnancy; serology; SARS-CoV-2; Microbiology; QR1-502 |
| Description: |
Antibody surveillance provided valuable public health insights during the Coronavirus Disease 2019 (COVID-19) pandemic. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, vaccination, and cross-reactive responses from endemic coronaviruses (human coronaviruses [HCoVs]) can influence SARS-CoV-2 antibody responses, impacting reliability and interpretation of serological findings. Here, we investigated population-level SARS-CoV-2 and HCoV IgA and IgG responses following SARS-CoV-2 infection among unvaccinated and vaccinated pregnant individuals over 3 months. Using residual sera from routine antenatal screening of pregnant individuals in British Columbia between March 2020 to May 2022, we designed a retrospective repeated cross-sectional cohort of infected individuals either unvaccinated (UV + COV, N = 171) or two- to three-dose vaccinated (V + COV, N = 137). A total of 30 pre-pandemic sera served as negative controls. Sera were collected within 3 months of respiratory PCR-positivity in half-month intervals and tested for IgA and IgG against Spike (S) of alpha-HCoV (HCoV-229E, HCoV-NL63) and beta-HCoV (HCoV-HKU1, HCoV-OC43) and S, receptor binding domain, and nucleocapsid (N) of SARS-CoV-2 using a multiplex immunoassay. Following SARS-CoV-2 infection, V + COV had lower anti-N IgG levels (P = 0.004) and seropositivity rates than UV + COV. One month post-infection, V + COV (38%) had lower anti-N IgA seropositivity than UV + COV (73%). Both groups had significantly higher anti-S IgA and IgG levels against beta-HCoV vs controls, with signals correlating positively with SARS-CoV-2 anti-S levels for each isotype. These results suggest that neither IgA nor IgG can reliably identify recent infections in vaccinated populations, emphasizing the importance of considering complex interplay of antibody responses when interpreting serological data and recognizing the potential and limitations of serological testing for diagnostics and surveillance.IMPORTANCEThis study provides key insights into how ... |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
https://doaj.org/toc/2165-0497; https://doaj.org/article/cbea589847c54f98b00af8a79b6330c2 |
| DOI: |
10.1128/spectrum.02167-25 |
| Availability: |
https://doi.org/10.1128/spectrum.02167-25; https://doaj.org/article/cbea589847c54f98b00af8a79b6330c2 |
| Accession Number: |
edsbas.DAE701D7 |
| Database: |
BASE |