Population-based sero-epidemiological investigation of SARS-CoV-2 infection in Somalia

Hossain, Md Shajib; Derrow, Mohamed Mohamud; Mohamed, Sahra Isse; Abukar, Hasan Mukhtar; Qayad, Mohamed; Malik, Sk Md Mamunur Rahman; Mengistu, Kumlachew Fikremariam; Obsie, Ali Abdilahi Ali; Anwar, Iqbal

doi:10.1016/j.jiph.2023.04.016

Cited by 3 publications

(4 citation statements)

References 21 publications

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“…Within the 2021 blood donor cohort, seroprevalence reached 61%. This finding is slightly lower than others in the country which have reported up to 70% 13,14,48 and similar to surveys in Somalia, 18 Uganda, 19 Nigeria, 22 Burkina Faso 49 or South Africa 50,51 where antibody detection between 56% and 67% by 2021 has been reported. Although much lower seroprevalence has been estimated in studies in the Republic of the Congo (31.8%) 11 and Gabon (13%), 52 both relied on lateral‐flow rapid immunochromatography tests, which could justify the difference.…”

Section: Discussionsupporting

confidence: 76%

“…No significant differences in seroprevalence were found amongst sexes (2021 cohort) nor age groups (2021 and 2022 cohorts). This observation has been made by numerous authors, both in individual countries 13,18,21,24,50 and upon meta‐analysis, 47,53 where seroprevalence was not significantly different by these categories. Some authors have suggested that transmission reached such high levels by 2022 that none of the potential risk factors studied could be associated with antibody detection 16 …”

Section: Discussionsupporting

confidence: 54%

“…This finding is in agreement with others at a similar time in the continent: serosurveys in Cameroon, Gambia, Uganda and South Africa have reported antibody positivity between 87% and 96% during the Omicron wave. 16,17,19,50,54 13,18,21,24,50 and upon meta-analysis, 47,53 where seroprevalence was not significantly different by these categories. Some authors have suggested that transmission reached such high levels by…”

Section: Assessment Of the Validity Of Sars-cov-2 Serological Tests I...mentioning

confidence: 91%

“…In contrast, studies in the DRC have found seroprevalences ranging from 48% 12 to 70% 13,14 . A similar phenomenon has occurred in neighboring countries such as Republic of the Congo, 15 Cameroon, 16 Gambia, 17 Somalia, 18 Uganda, 12,14,19 Tanzania, 20 Nigeria 12,21,22 and Kenya, 23–25 where growing evidence indicates pandemic burden has been grossly underestimated.…”

Section: Introductionmentioning

confidence: 92%

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High pre‐Delta and early‐Omicron SARS‐CoV‐2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo)

de Aguirre,

Carlos,

Pina‐Sánchez

et al. 2024

Journal of Medical Virology

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Studies on the impact of the COVID‐19 pandemic in sub‐Saharan Africa have yielded varying results, although authors universally agree the real burden surpasses reported cases. The primary objective of this study was to determine SARS‐CoV‐2 seroprevalence among patients attending Monkole Hospital in Kinshasa (D.R. Congo). The secondary objective was to evaluate the analytic performance of two chemiluminescence platforms: Elecsys® (Roche) and VirClia® (Vircell) on dried blood spot samples (DBS). The study population (N = 373) was recruited in two stages: a mid‐2021 blood donor cohort (15.5% women) and a mid‐2022 women cohort. Crude global seroprevalence was 61% (53.9%–67.8%) pre‐Delta in 2021 and 90.2% (84.7%–94.2%) post‐Omicron in 2022. Anti‐spike (S) antibody levels significantly increased from 53.1 (31.8–131.3) U/mL in 2021 to 436.5 (219.3–950.5) U/mL in 2022 and were significantly higher above 45 years old in the 2022 population. Both platforms showed good analytic performance on DBS samples: sensitivity was 96.8% for IgG (antiN/S) (93.9%–98.5%) and 96.0% (93.0%–98.0%) for anti‐S quantification. These results provide additional support for the notion that exposure to SARS‐CoV‐2 is more widespread than indicated by case‐based surveillance and will be able to guide the pandemic response and strategy moving forward. Likewise, this study contributes evidence to the reliability of DBS as a tool for serological testing and diagnosis in resource‐limited settings.

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Section: Discussionsupporting

confidence: 76%

Section: Discussionsupporting

confidence: 54%

Section: Assessment Of the Validity Of Sars-cov-2 Serological Tests I...mentioning

confidence: 91%

Section: Introductionmentioning

confidence: 92%

See 2 more Smart Citations

High pre‐Delta and early‐Omicron SARS‐CoV‐2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo)

de Aguirre,

Carlos,

Pina‐Sánchez

et al. 2024

Journal of Medical Virology

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Safety and Immunogenicity of Fractional Doses of COVID-19 Vaccines among Nigerian Adults- A Randomised Non-Inferiority trial

Olurotimi,

Zaidat,

Anthonia

et al. 2024

Preprint

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The shortage of COVID-19 vaccines posed a significant challenge in optimal response to the COVID-19 pandemic. Fractional doses of vaccine with adequate immunogenic response and proven safety profile emerged as potential strategy to extend the limited vaccine doses. This study was aimed to evaluate the immunogenicity and safety of fractional doses of the ChadOx1, Ad26.COV2.S, and BNT162B2 vaccines among healthy Nigerian adults. A non-inferiority multi-site triple-blind clinical trial was undertaken in Nigeria. Healthy Nigerian adults (18-65 years) who met the inclusion criteria were enrolled in the study. Participants were block-randomized into three vaccine arms (ChadOx1 quarter, half, and full dose; Ad26.COV2.S: quarter, half and full dose; and BNT162B2: half and full dose) . Participants, clinical staff (clinicians and nurses) and laboratory personnel were blinded. The primary objective of the study was to evaluate non-inferiority in seroconversion rates, defined as geometric mean fold rise (GMFR) ≥ 2.5 in serum anti-spike IgG titre at 28 days post-vaccination by ELISA. Immunogenicity analysis included use of serum neutralization assays using pseudotyped virus bearing spike from Wu-1 and Omicron variants. A total of 1891 participants were enrolled between June 21, 2022, and January 25, 2023. 320 participants in the fractional dose group and 220 in the standard dose group completed follow-up and were included in the analysis. SARS-CoV-2 seropositivity at baseline was high, at 68% (365/539). Seroconversion (geometric mean fold rise) was comparable between standard and fractional doses. For ChAdOx1, 31% achieved ≥ 2.5 fold change increase in serum binding antibody in the standard dose arm (16/52), 28% in half dose (15/53), and 34% in quarter dose (18/53). For Ad26.COV2.S, the proportions were 27% (28/105) in standard dose, 32% (22/68) in half dose, and 30% (21/71) in quarter dose arms respectively. For BNT162N2, the proportions were 43% (27/63) in standard dose and 39% (29/75) in half dose. Subset analysis of binding and neutralization responses in (n=64) participants demonstrated high degree of of prior exposure to SARS-CoV-2 ancestral and Omicron lineage variants prior to vaccination. Serum neutralization responses showed ≥2-fold response to both full and fractional doses indicating immunogenic responses to the vaccine dosing regimens. There was no report of serious adverse events. Fractional vaccine doses showed potential to generate non-inferior immune responses compared to standard doses in the context of a population with high rate of previous exposure to SARS-CoV-2 infection. The three vaccines are safe and well tolerated. Fractional dose should be considered to boost herd immunity and prevent outbreaks of SARS-COV-2.

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Methods employed in a 2021 population-based serosurvey in Somalia

Hossain,

Ali,

Clary

et al. 2024

Gates Open Res

Self Cite

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This paper describes the design and methods of a serosurvey conducted in Somalia in 2021. The study had several concurrent aims: a) to estimate seroprevalence of antibodies to SARS-CoV-2, b) to obtain age-specific data on susceptibility to poliovirus, measles, rubella, diphtheria, and tetanus; and c) to estimate seroprevalence of pathogens causing malaria and neglected tropical diseases. Participants were recruited from persons seeking care at government health facilities as well as friends and family members who accompanied those seeking care. Respondents answered interview questions to establish their demographic profile, their COVID-19 exposure and experience, and, for children, their routine immunization status. Each participant contributed a sample of blood for serum or dried blood spots. Serum samples were analyzed in Somalia for SARS-CoV-2 and dried blood spots were analyzed at the US Centers for Disease Control and Prevention (US CDC) for the other diseases and antigens of interest. This manuscript describes the study design, logistics, laboratory methods, and data management steps used to compile the study dataset. Study results will be reported in a series of manuscripts to follow.

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Population-based sero-epidemiological investigation of SARS-CoV-2 infection in Somalia

Cited by 3 publications

References 21 publications

High pre‐Delta and early‐Omicron SARS‐CoV‐2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo)

High pre‐Delta and early‐Omicron SARS‐CoV‐2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo)

Safety and Immunogenicity of Fractional Doses of COVID-19 Vaccines among Nigerian Adults- A Randomised Non-Inferiority trial

Methods employed in a 2021 population-based serosurvey in Somalia

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