SARS-CoV-2 seroprevalence in the urban population of Qatar: An analysis of antibody testing on a sample of 112,941 individuals

Coyle, Peter; Chemaitelly, Hiam; Kacem, Mohamed Ali Ben Hadj; Molawi, Naema Hassan Abdulla Al; Kahlout, Reham Awni El; Gilliani, Imtiaz; Younes, Nagy; Anssari, Ghada Ali A.A. Al; Kanaani, Zaina Al; Khal, Abdullatif Al; Kuwari, Einas Al; Butt, Adeel A.; Jeremijenko, Andrew; Kaleeckal, Anvar Hassan; Latif, Ali Nizar; Shaik, Riyazuddin Mohammad; Rahim, Hanan F. Abdul; Nasrallah, Gheyath K.; Yassine, Hadi M.; Al‐Kuwari, Mohamed Ghaith; Romaihi, Hamad Eid Al; Al-Thani, Mohamed H.; Bertollini, Roberto; Abu-Raddad, Laith J

doi:10.1016/j.isci.2021.102646

Cited by 83 publications

(76 citation statements)

References 30 publications

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“…E.g., relaxation of measures in 2021 may have been more prominent among non-elderly populations. This hypothesis is difficult to prove or disprove, but careful, serial seroprevalence studies ( Bajema et al, 2021 ; Kshatri et al, 2021 ; Coyle et al, 2021 ; Stadlbauer et al, 2021 ; Bogogiannidou et al, 2020 ; Nisar et al, 2021 ) may help understand the potential change in population spread of the infection during 2021 versus 2020. Moreover, new variants did circulate widely in many countries during early 2021 ( Konings et al, 2021 ).…”

Section: Discussionmentioning

confidence: 99%

Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination

Pastorino

Pezzullo

Villani

et al. 2022

Environmental Research

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Section: Discussionmentioning

confidence: 99%

Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination

Pastorino

Pezzullo

Villani

et al. 2022

Environmental Research

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“…There were small differences in median age and sex, but large differences in age distribution, nationality, and calendar month of dose 1 reflecting introduction of the mRNA-1273 vaccine 3 months after BNT162b2 (eFigure 1 in the Supplement), and a phased vaccine rollout prioritizing frontline health care workers, persons with severe or multiple chronic conditions, select occupational groups such as teachers, and age, all in context of associations with age, nationality, and occupation. 8,15,[20][21][22] Qatar has unusually young, diverse demographics, in that only 9% of its residents are 50 years or older, and 89% are expatriates residing in Qatar on work visas from more than 150 countries, of whom most are male. 15,23 A median of 21 days (IQR,(21)(22) elapsed between the first and second BNT162b2 doses; 97.4% of individuals received their second dose 30 days or less after their first dose.…”

Section: Study Populationmentioning

confidence: 99%

“…Matching by nationality may have captured some of the occupational risk, given the distribution of the labor force in Qatar. [20][21][22] The number of persons with severe or multiple chronic conditions is small in Qatar. The national list of vaccine prioritization included only 19 800 individuals of all age groups with serious comorbid conditions to be prioritized in the first phase of vaccine roll-out.…”

Section: Limitationsmentioning

confidence: 99%

Association of Prior SARS-CoV-2 Infection With Risk of Breakthrough Infection Following mRNA Vaccination in Qatar

Abu‐Raddad

Chemaitelly

Ayoub

et al. 2021

JAMA

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IMPORTANCEThe effect of prior SARS-CoV-2 infection on vaccine protection remains poorly understood.OBJECTIVE To assess protection from SARS-CoV-2 breakthrough infection after mRNA vaccination among persons with vs without prior SARS-CoV-2 infection.DESIGN, SETTING, AND PARTICIPANTS Matched-cohort studies in Qatar for the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines. A total of 1 531 736 individuals vaccinated with either vaccine between December 21, 2020, and September 19, 2021, were followed up beginning 14 days after receiving the second dose until September 19, 2021.EXPOSURES Prior SARS-CoV-2 infection and COVID-19 vaccination. MAIN OUTCOMES AND MEASURESIncident SARS-CoV-2 infection, defined as a polymerase chain reaction (PCR)-positive nasopharyngeal swab regardless of reason for PCR testing or presence of symptoms. Cumulative incidence was calculated using the Kaplan-Meier estimator method. RESULTSThe BNT162b2-vaccinated cohort comprised 99 226 individuals with and 290 432 matched individuals without prior PCR-confirmed infection (median age, 37 years; 68% male). The mRNA-1273-vaccinated cohort comprised 58 096 individuals with and 169 514 matched individuals without prior PCR-confirmed infection (median age, 36 years; 73% male). Among BNT162b2-vaccinated persons, 159 reinfections occurred in those with and 2509 in those without prior infection 14 days or more after dose 2. Among mRNA-1273-vaccinated persons, 43 reinfections occurred in those with and 368 infections in those without prior infection. Cumulative infection incidence among BNT162b2-vaccinated individuals was an estimated 0.15% (95% CI, 0.12%-0.18%) in those with and 0.83% (95% CI, 0.79%-0.87%) in those without prior infection at 120 days of follow-up (adjusted hazard ratio for breakthrough infection with prior infection, 0.18 [95% CI, 0.15-0.21]; P < .001). Cumulative infection incidence among mRNA-1273-vaccinated individuals was an estimated 0.11% (95% CI, 0.08%-0.15%) in those with and 0.35% (95% CI, 0.32%-0.40%) in those without prior infection at 120 days of follow-up (adjusted hazard ratio, 0.35 [95% CI, 0.25-0.48]; P < .001). Vaccinated individuals with prior infection 6 months or more before dose 1 had statistically significantly lower risk for breakthrough infection than those infected less than 6 months before dose 1 (adjusted hazard ratio, 0.62 [95% CI, 0.42-0.92]; P = .02 for BNT162b2 and 0.40 [95% CI, 0.18-0.91]; P = .03 for mRNA-1273 vaccination). CONCLUSIONS AND RELEVANCEPrior SARS-CoV-2 infection was associated with a statistically significantly lower risk for breakthrough infection among individuals receiving the BNT162b2 or mRNA-1273 vaccines in Qatar between December 21, 2020, and September 19, 2021. The observational study design precludes direct comparisons of infection risk between the 2 vaccines.

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“…Qatar also launched a mass coronavirus disease 2019 (COVID-19) immunization campaign on 21 December 2020, using the BNT162b2 (Pfizer-BioNTech) [5] and mRNA-1273 (Moderna) [6] vaccines, but vaccine coverage was limited before the end of March 2021 [7][8][9]. The first wave in Qatar has been thoroughly investigated and featured 2 subepidemics [1,2,4,[10][11][12][13][14][15][16][17][18]. The first subepidemic emerged among craft and manual workers [1,3].…”

Section: Introductionmentioning

confidence: 99%

Introduction and expansion of the SARS-CoV-2 B.1.1.7 variant and reinfections in Qatar: A nationally representative cohort study

et al. 2021

Self Cite

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Background The epidemiology of the SARS-CoV-2 B.1.1.7 (or Alpha) variant is insufficiently understood. This study’s objective was to describe the introduction and expansion of this variant in Qatar and to estimate the efficacy of natural infection against reinfection with this variant. Methods and findings Reinfections with the B.1.1.7 variant and variants of unknown status were investigated in a national cohort of 159,003 individuals with prior PCR-confirmed infections and a national cohort of 43,127 antibody-positive individuals. Infections with B.1.1.7 and variants of unknown status were also investigated in a national comparator cohort of 150,106 antibody-negative individuals. B.1.1.7 was first identified in Qatar on 25 December 2020. Sudden, large B.1.1.7 epidemic expansion was observed starting on 18 January 2021, triggering the onset of epidemic’s second wave, 7 months after the first wave. B.1.1.7 was about 60% more infectious than the original (wild-type) circulating variants. Among persons with a prior PCR-confirmed infection, the efficacy of natural infection against reinfection was estimated to be 97.5% (95% CI: 95.7% to 98.6%) for B.1.1.7 and 92.2% (95% CI: 90.6% to 93.5%) for variants of unknown status. Among antibody-positive persons, the efficacy of natural infection against reinfection was estimated to be 97.0% (95% CI: 92.5% to 98.7%) for B.1.1.7 and 94.2% (95% CI: 91.8% to 96.0%) for variants of unknown status. A main limitation of this study is assessment of reinfections based on documented PCR-confirmed reinfections, but other reinfections could have occurred and gone undocumented. Conclusions In this study, we observed that introduction of B.1.1.7 into a naïve population can create a major epidemic wave, but natural immunity in those previously infected was strongly associated with limited incidence of reinfection by B.1.1.7 or other variants.

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SARS-CoV-2 seroprevalence in the urban population of Qatar: An analysis of antibody testing on a sample of 112,941 individuals

Cited by 83 publications

References 30 publications

Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination

Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination

Association of Prior SARS-CoV-2 Infection With Risk of Breakthrough Infection Following mRNA Vaccination in Qatar

Introduction and expansion of the SARS-CoV-2 B.1.1.7 variant and reinfections in Qatar: A nationally representative cohort study

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