Mandolo, Jonathan, Msefula, Jacquline, Henrion, Marc YR, Brown, Comfort, Moyo, Brewster, Samon, Aubrey, Moyo-Gwete, Thandeka, Makhado, Zanele, Ayres, Frances, Motlou, Thopisang et al (show 13 more authors)
(2021)
SARS-CoV-2 exposure in Malawian blood donors: an analysis of seroprevalence and variant dynamics between January 2020 and July 2021.
BMC MEDICINE, 19 (1).
303-.
Abstract
<h4>Background</h4>By August 2021, the COVID-19 pandemic has been less severe in sub-Saharan Africa than elsewhere. In Malawi, there have been three subsequent epidemic waves. We therefore aimed to describe the dynamics of SARS-CoV-2 exposure in Malawi.<h4>Methods</h4>We measured the seroprevalence of anti-SARS-CoV-2 antibodies amongst randomly selected blood transfusion donor sera in Malawi from January 2020 to July 2021 using a cross-sectional study design. In a subset, we also assessed in vitro neutralisation against the original variant (D614G WT) and the Beta variant.<h4>Results</h4>A total of 5085 samples were selected from the blood donor database, of which 4075 (80.1%) were aged 20-49 years. Of the total, 1401 were seropositive. After adjustment for assay characteristics and applying population weights, seropositivity reached peaks in October 2020 (18.5%) and May 2021 (64.9%) reflecting the first two epidemic waves. Unlike the first wave, both urban and rural areas had high seropositivity in the second wave, Balaka (rural, 66.2%, April 2021), Blantyre (urban, 75.6%, May 2021), Lilongwe (urban, 78.0%, May 2021), and Mzuzu (urban, 74.6%, April 2021). Blantyre and Mzuzu also show indications of the start of a third pandemic wave with seroprevalence picking up again in July 2021 (Blantyre, 81.7%; Mzuzu, 71.0%). More first wave sera showed in vitro neutralisation activity against the original variant (78% [7/9]) than the beta variant (22% [2/9]), while more second wave sera showed neutralisation activity against the beta variant (75% [12/16]) than the original variant (63% [10/16]).<h4>Conclusion</h4>The findings confirm extensive SARS-CoV-2 exposure in Malawi over two epidemic waves with likely poor cross-protection to reinfection from the first on the second wave. The dynamics of SARS-CoV-2 exposure will therefore need to be taken into account in the formulation of the COVID-19 vaccination policy in Malawi and across the region. Future studies should use an adequate sample size for the assessment of neutralisation activity across a panel of SARS-CoV-2 variants of concern/interest to estimate community immunity.
Item Type: | Article |
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Uncontrolled Keywords: | SARS-CoV-2, Seroprevalence, Malawi, Blood donors |
Divisions: | Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences |
Depositing User: | Symplectic Admin |
Date Deposited: | 29 Nov 2021 10:27 |
Last Modified: | 18 Jan 2023 21:23 |
DOI: | 10.1186/s12916-021-02187-y |
Open Access URL: | https://bmcmedicine.biomedcentral.com/track/pdf/10... |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3144151 |