SARS-CoV-2 IgG seropositivity after the severe Omicron wave of COVID-19 in Hong Kong
Open accessAbstract
The SARS-CoV-2 Omicron variant has led to a major wave of COVID-19 in Hong Kong between January and May 2022. Here, we used seroprevalence to estimate the combined incidence of vaccination and SARS-CoV-2 infection, including subclinical infection which were not diagnosed at the acute stage. The overall seropositive rate of IgG against receptor binding domain (anti-RBD IgG) increased from 52.2% in December 2021 to 89.3% in May 2022. The level of anti-RBD IgG was lowest in the 0-9 and ≥80 year-old age groups in May 2022. The seropositive rate of antibody against ORF8, which reflects the rate of prior infection, was 23.4% in May 2022. Our data suggest that although most individuals were either vaccinated or infected after the fifth wave, children and older adults remain most vulnerable. Public health measures should target these age groups in order to ameliorate the healthcare consequences of upcoming waves.
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Reliance on healthy blood donors and voluntary child participants did not result in a material underestimate of COVID-19 seroprevalence in the general population.
“These independent estimates provide confidence that our reliance on healthy blood donors and voluntary child participants did not result in a material underestimate of COVID-19 seroprevalence in the general population.”
From Real-world COVID-19 vaccine effectiveness against the Omicron BA.2 variant in a SARS-CoV-2 infection-naive population (2023) · cites this paper as [51]
The Methods description reports archived serum or plasma specimens, not a sample of healthy blood donors and voluntary child participants. The Discussion notes that specimens from hospital patients may not represent healthy people, but does not assess whether donor or child-participant selection materially underestimated population seroprevalence. Searches for blood donors, voluntary child participants, and independent estimates found no such assessment in our copy. (LLM, conf=0.76)
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- Authors
- Poon, R. W.-S., Chan, B. P.-C., Chan, W.-M., Fong, C. H.-Y., Zhang, X., Lu, L., Chen, L.-L., Lam, J.-Y., Cheng, V. C.-C., Wong, S. S. Y., Kok, K.-H., Yuen, K.-Y., & To, K. K.-W.
- Affiliations
- Queen Mary Hospital (CN)
- University of Hong Kong (HK)
- Hong Kong Science and Technology Parks Corporation (HK)
- Corresponding author
- To, Kelvin Kai-Wang
- ORCID
- Venue
- Emerging Microbes & Infections
- Publisher
- Informa UK Limited
- Published
- 2022-09-05
- Volume
- 11
- Issue
- 1
- Pages
- 2116-2119
- ISSN
- 2222-1751 (ISSN-L)
- PMC
- PMC9448364
- OpenAlex
- W4287981083
- Cited by
- 20
- References
- 14
- Citations by year
- 2025: 1 · 2024: 5 · 2023: 10 · 2022: 4
- FWCI
- 2.44
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Emerging Microbes & Infections (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Funders
- Ministry of Science and Technology
- PRC
- Foundation of Hubei Polytechnic University (2021YFC0866100)
- Consultancy Service for Enhancing Laboratory Surveillance of Emerging Infectious Diseases and Research Capability on Antimicrobial Resistance for Department of Health of the Hong Kong SAR Government
- Topics
- Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
- Physical Sciences › Mathematics › Modeling and Simulation › COVID-19 epidemiological studies
- Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
- Keywords
- Omicron variant, COVID-19 pandemic, seroprevalence, anti-RBD IgG, vaccination coverage, asymptomatic infection, age groups, children, older adults, Hong Kong
- MeSH terms
- COVID-19, SARS-CoV-2, Aged, Aged, 80 and over, Antibodies, Viral, Child, Hong Kong, Humans, Immunoglobulin G, Seroepidemiologic Studies
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