Item request has been placed!
×
Item request cannot be made.
×
Processing Request
Characterizing the evolving SARS-CoV-2 seroprevalence in urban and rural Malawi between February 2021 and April 2022: A population-based cohort study.
Item request has been placed!
×
Item request cannot be made.
×
Processing Request
- Author(s): Banda, Louis1 (AUTHOR); Ho, Antonia1,2 (AUTHOR) ; Kasenda, Stephen1 (AUTHOR); Read, Jonathan M.3 (AUTHOR); Jewell, Chris3 (AUTHOR); Price, Alison1,4 (AUTHOR); McLean, Estelle1,4 (AUTHOR); Dube, Albert1 (AUTHOR); Chaima, David5 (AUTHOR); Samikwa, Lyson5 (AUTHOR); Nyirenda, Tonney S.5 (AUTHOR); Hughes, Ellen C.2 (AUTHOR); Willett, Brian J.2 (AUTHOR); Mwale, Annie Chauma6 (AUTHOR); Amoah, Abena S.1,4,7 (AUTHOR); Crampin, Amelia1,4,8 (AUTHOR)
- Source:
International Journal of Infectious Diseases. Dec2023, Vol. 137, p118-125. 8p.
- Subject Terms:
- Additional Information
- Subject Terms:
- Abstract:
• This was a longitudinal SARS-CoV-2 serosurvey in an urban & rural cohort in Malawi. • Post-Omicron SARS-CoV-2 seroprevalence was very high (rural: 89%; urban: 94%). • Most SARS-CoV-2 infections were subclinical; few required healthcare attendance. • Seroconversion risk varied by location & age across the successive infection waves. • Hybrid immunity was associated with higher seroprevalence and antibody titers. This study aimed to investigate the changing SARS-CoV-2 seroprevalence and associated health and sociodemographic factors in Malawi between February 2021 and April 2022. In total, four 3-monthly serosurveys were conducted within a longitudinal population-based cohort in rural Karonga District and urban Lilongwe, testing for SARS-CoV-2 S1 immunoglobulin (Ig)G antibodies using an enzyme-linked immunosorbent assay. Population seroprevalence was estimated in all and unvaccinated participants. Bayesian mixed-effects logistic models estimated the odds of seropositivity in the first survey, and of seroconversion between surveys, adjusting for age, sex, occupation, location, and assay sensitivity/specificity. Of the 2005 participants (Karonga, n = 1005; Lilongwe, n = 1000), 55.8% were female and median age was 22.7 years. Between Surveys (SVY) 1 and 4, population-weighted SARS-CoV-2 seroprevalence increased from 26.3% to 89.2% and 46.4% to 93.9% in Karonga and Lilongwe, respectively. At SVY4, seroprevalence did not differ by COVID-19 vaccination status in adults, except for those aged 30+ years in Karonga (unvaccinated: 87.4%, 95% credible interval 79.3-93.0%; two doses: 98.1%, 94.8-99.5%). Location and age were associated with seroconversion risk. Individuals with hybrid immunity had higher SARS-CoV-2 seropositivity and antibody titers, than those infected. High SARS-CoV-2 seroprevalence combined with low morbidity and mortality indicate that universal vaccination is unnecessary at this stage of the pandemic, supporting change in national policy to target at-risk groups. [ABSTRACT FROM AUTHOR]
No Comments.