PREPRINT: Assessing the Burden of COVID-19 in Developing Countries: Systematic Review, Meta-Analysis, and Public Policy Implications

Abstract
Introduction The infection-fatality rate (IFR) of COVID-19 has been carefully measured and analyzed in high-income countries, whereas there has been no systematic analysis of age-specific seroprevalence or IFR for developing countries. Indeed, it has been suggested that the death rate in developing countries may be far lower than in high-income countries—an outcome that would be starkly different from the typical pattern for many other infectious diseases.

Methods We systematically reviewed the literature to identify all serology studies in developing countries that were conducted using representative samples of specimens collected by early 2021. For each of the antibody assays used in these serology studies, we identified data on assay characteristics, including the extent of seroreversion over time. We analyzed the serology data using a Bayesian model that incorporates conventional sampling uncertainty as well as uncertainties about assay sensitivity and specificity. We then calculated IFRs using individual case reports or aggregated public health updates, including age-specific estimates whenever feasible.

Results Seroprevalence in many developing country locations was markedly higher than in high-income countries but still far short of herd immunity. In most locations, seroprevalence among older adults was similar to that of younger age-groups. Age-specific IFRs were 1.3-2.5x higher than in high-income countries. The median value of population IFR was 0.5% among developing countries with satisfactory death reporting as of 2016, compared to a median of 0.05% for other developing countries.

Conclusion The burden of COVID-19 is far higher in developing countries than in high-income countries, reflecting a combination of elevated transmission to middle-aged and older adults as well as limited access to adequate healthcare. These results underscore the critical need to accelerate the provision of vaccine doses to vulnerable populations in developing countries.

Key Points

‐ Age-specific prevalence and infection fatality rate (IFR) of COVID-19 for developing countries has not been well assessed.

‐ Seroprevalence in developing countries (as measured by antibodies against SARS-CoV-2) is markedly higher than in high-income countries but still far short of herd immunity.

‐ Seroprevalence among older adults is broadly similar to that of younger age-groups.

‐ Age-specific IFRs in developing countries are roughly twice those of high-income countries.

‐ Population IFR in developing countries with satisfactory death reporting (based on UN/WHO data as of 2016) is ten times higher than in other developing countries.

‐ These results underscore the urgency of disseminating vaccines to vulnerable people in developing countries.

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