ArticlePloS one2022
IgG antibodies to SARS-CoV-2 in asymptomatic blood donors at two time points in Karachi.
Article in PloS one, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 9 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
9 citing papers in PubMed, 21 citations in OpenAlex.
- Evidence of rapid rise in population immunity from SARS-CoV-2 subclinical infections through pre-vaccination serial serosurveys in Pakistan.Journal of global health · 2025Article
- Pre-existing IgG antibodies to HCoVs NL63 and OC43 Spike increased during the pandemic and after COVID-19 vaccination.Heliyon · 2025Article
- Individuals with latent tuberculosis in a high TB endemic country show mild COVID-19.PloS one · 2025Article
- Correction: IgG antibodies to SARS-CoV-2 in asymptomatic blood donors at two time points in Karachi.PloS one · 2024Article
- Humoral and T cell responses to SARS-CoV-2 reveal insights into immunity during the early pandemic period in Pakistan.BMC infectious diseases · 2023Article
- Substitution spectra of SARS-CoV-2 genome from Pakistan reveals insights into the evolution of variants across the pandemic.Scientific reports · 2023Article
- Investigating the impact of prior COVID-19 on IgG antibody and interferon γ responses after BBIBP-CorV vaccination in a disease endemic population: A prospective observational study.Health science reports · 2023Article
- Article
- ABO Blood Groups and Incidence of COVID-19 in the Mass Gathering Events in Borriana (Spain), March 2020: A Retrospective Cohort Study.Epidemiologia (Basel, Switzerland) · 2023Article
Corrections and comments
- Erratum issued
Authors and funding
14 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionAn estimated 1.5 million cases were reported in Pakistan until 23 March, 2022. However, SARS-CoV-2 PCR testing capacity has been limited and the incidence of COVID-19 infections is unknown. Volunteer healthy blood donors can be a control population for assessment of SARS-CoV-2 exposure in the population. We determined COVID-19 seroprevalence during the second pandemic wave in Karachi in donors without known infections or symptoms in 4 weeks prior to enrollment. MATERIALS AND
methodsWe enrolled 558 healthy blood donors at the Aga Khan University Hospital between December 2020 and February 2021. ABO blood groups were determined. Serum IgG reactivity were measured to spike and receptor binding domain (RBD) proteins.
resultsStudy subjects were predominantly males (99.1%) with a mean age of 29.0±7.4 years. Blood groups were represented by; B (35.8%), O (33.3%), A (23.8%) and AB (7%). Positive IgG responses to spike were detected in 53.4% (95% CI, 49.3-37.5) of blood donors. Positive IgG antibodies to RBD were present in 16.7% (95% CI; 13.6-19.8) of individuals. No significant difference was found between the frequency of IgG antibodies to spike or RBD across age groups. Frequencies of IgG to Spike and RBD antibodies between December 2020 and February 2021 were found to be similar. Seropositivity to either antigen between individuals of different blood groups did not differ. Notably, 31.2% of individuals with IgG antibodies to spike also had IgG antibodies to RBD. Amongst donors who had previously confirmed COVID-19 and were seropositive to spike, 40% had IgG to RBD.
conclusionsOur study provides insights into the seroprevalence of antibodies to COVID-19 in a healthy cohort in Karachi. The differential dynamics of IgG to spike and RBD likely represent both exposure to SARS-CoV-2 and associate with protective immunity in the population.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.