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Cited by 98COVID-19 epidemiological studiesSARS-CoV-2 and COVID-19 ResearchCOVID-19 Clinical Research Studies

Herd Immunity against Severe Acute Respiratory Syndrome Coronavirus 2 Infection in 10 Communities, Qatar

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Jeremijenko, Andrew, Chemaitelly, Hiam, Ayoub, Houssein H., Alishaq, Moza, Abou-Samra, Abdul-Badi, Al Ajmi, Jameela Ali A.A., Al Ansari, Nasser Ali Asad, Al Kanaani, Zaina +23 more·2021·Emerging Infectious Diseases
DOI 10.3201/eid2705.204365PMC PMC8084480

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Abstract

ABSTRACT Background Qatar experienced a large severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic that disproportionately affected the craft and manual workers (CMWs) who constitute 60% of the population. This study aimed to investigate level of immunity in communities within this population as well as infection exposure required to achieve herd immunity. Methods Anti - SARS-CoV-2 seropositivity was assessed in ten CMW communities between June 21 and September 9, 2020. PCR positivity, infection positivity (antibody and/or PCR positive), and infection severity rate were also estimated. Associations with anti-SARS-CoV-2 positivity were investigated using regression analyses. Results Study included 4,970 CMWs who were mostly men (95.0%) and <40 years of age (71.5%). Seropositivity ranged from 54.9% (95% CI: 50.2-59.4%) to 83.8% (95% CI: 79.1-87.7%) in the different CMW communities. Pooled mean seropositivity across all communities was 66.1% (95% CI: 61.5-70.6%). PCR positivity ranged from 0.0% to 10.5% (95% CI: 7.4-14.8%) in the different CMW communities. Pooled mean PCR positivity was 3.9% (95% CI: 1.6-6.9%). Median cycle threshold (Ct) value was 34.0 (range: 15.8-37.4)—majority (79.5%) of PCR-positive individuals had Ct value >30 indicative of earlier rather than recent infection. Infection positivity (antibody and/or PCR positive) ranged from 62.5% (95% CI: 58.3-66.7%) to 83.8% (95% CI: 79.1-87.7%) in the different CMW communities. Pooled mean infection positivity was 69.5% (95% CI: 62.8-75.9%). Only five infections were ever severe and one was ever critical—an infection severity rate of 0.2% (95% CI: 0.1-0.4%). Conclusions Based on an extended range of epidemiological measures, active infection is rare in these communities with limited if any sustainable infection transmission for clusters to occur. At least some CMW communities in Qatar have reached or nearly reached herd immunity for SARS-CoV-2 infection at a proportion of ever infection of 65-70%.

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  • Cases and controls were exact-matched by sex, 10-year-age group, nationality, and calendar week of PCR test to control for established differences in risk of exposure to SARS-CoV-2 infection in Qatar.

    “Cases (persons infected with BA.1, BA.2, or any-Omicron-subvariant) and controls (uninfected persons) were exact-matched by sex, 10-year-age group, nationality, and calendar week of polymerase chain reaction (PCR) test to control for established differences in the risk of exposure to SARS-CoV-2 infection in Qatar15–19.”

    From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [19]

  • Earlier seroprevalence studies conducted in the same population have shown that a considerable proportion of SARS-CoV-2 infections went undocumented.

    “Earlier seroprevalence studies conducted in the same population have shown that a considerable proportion of infections went undocumented17–19.”

    From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [19]

  • Matching was implemented to control for established differences in the risk of exposure to SARS-CoV-2 infection in Qatar.

    “Matching was implemented to control for established differences in the risk of exposure to SARS-CoV-2 infection in Qatar15–19.”

    From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [19]

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Authors
Jeremijenko, A., Chemaitelly, H., Ayoub, H. H., Alishaq, M., Abou-Samra, A.-B., Al Ajmi, J. A. A. A., Al Ansari, N. A. A., Al Kanaani, Z., Al Khal, A., Al Kuwari, E., Al-Mohammed, A., Al Molawi, N. H. A., Al Naomi, H. M., Butt, A. A., Coyle, P., El Kahlout, R. A., Gillani, I., Kaleeckal, A. H., Masoodi, N. A., Thomas, A. G., Nafady-Hego, H., Latif, A. N., Shaik, R. M., Younes, N. B. M., Rahim, H. F. A., Yassine, H. M., Al Kuwari, M. G., Al Romaihi, H. E., Al-Thani, M. H., Bertollini, R., & Abu-Raddad, L. J.
Affiliations
Cornell University (US)
Corresponding author
  • Jeremijenko, Andrew
  • Abu-Raddad, Laith J.
ORCID
Venue
Emerging Infectious Diseases
Publisher
Centers for Disease Control and Prevention (CDC)
Published
2021-05
Volume
27
Issue
5
Pages
1343-1352
ISSN
  • 1080-6040 (ISSN-L)
  • 1080-6059
DOI
10.3201/eid2705.204365
PMC
PMC8084480
OpenAlex
W3158710728
Cited by
97
References
35
Citations by year
2026: 5 · 2025: 10 · 2024: 11 · 2023: 15 · 2022: 26 · 2021: 27 · 2020: 3
FWCI
7.64
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Emerging infectious diseases (publishedVersion, cc-by)
  • medRxiv (acceptedVersion)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • LSHTM Research Online (London School of Hygiene and Tropical Medicine) (acceptedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Qatar University QSpace (Qatar University) (submittedVersion)
  • Greater South Information System
Funders
  • Hamad Medical Corporation
  • Weill Cornell Medical College
  • Weill Cornell Medicine - Qatar
Topics
  • Physical Sciences › Mathematics › Modeling and Simulation › COVID-19 epidemiological studies
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
Keywords
herd immunity, SARS-CoV-2, COVID-19 pandemic, community transmission, epidemic peak, epidemic curve, SARS-CoV-2 prevalence, Qatar
MeSH terms
COVID-19, SARS-CoV-2, Humans, Qatar, Immunity, Herd

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