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COVID-19 pandemic: The African paradox

AP reported this week that in spite of low vaccination rates, Africa has fared better than most of the world:

There is something “mysterious” going on in Africa that is puzzling scientists, said Wafaa El-Sadr, chair of global health at Columbia University. “Africa doesn’t have the vaccines and the resources to fight COVID-19 that they have in Europe and the U.S., but somehow they seem to be doing better,” she said …

Fewer than 6% of people in Africa are vaccinated. For months, the WHO has described Africa as “one of the least affected regions in the world” in its weekly pandemic reports.

With Low Vaccination Rates, Africa’s Covid Deaths Remain Far Below Europe and the US

Since COVID-19 became a pandemic, projection models were developed for Africa, with the assumption that SARS-CoV-2 has an exponential pattern of transmission.

Source: “Confirmed deaths per million, November 19, 2021“; “Share of people vaccinated against covid-19, November 19, 2021“.

Crowded social life and poor personal hygiene in Africa can be conducive for COVID-19 spread.

CLIMATE HYPOTHESIS

It has been argued since most human coronavirus infections associated with common cold symptoms peak in the winter months (December – April), and are undetectable during summer months in temperate regions of the world, SARS-CoV-2 infection will diminish as temperatures rise in the summer. Indeed, a recent study used a weather model to predict regions associated with a higher risk of COVID-19 community spread [*]. The high-risk temperate Western country zones and South Africa which have 5-11°C mean temperatures and 47%-79% relative humidity have more COVID-19 cases than tropical African countries (Figure 1, Panel A). In contrast, tropical Asian and Latin American countries are disproportionately infected by SARS-CoV-2 compared to tropical African countries (Figure 1, Panel A) suggesting other determinants than climate alone impact the spread of SARS-CoV-2. For example, living in high altitudes (less prone to hypoxia) appears to reduce transmission and death rates from COVID-19. So far, COVID-19 pandemic has shown a markedly low proportion of cases among young people, and this could be the reason why COVID-19 death rate is the lowest in African countries except South Africa. COVID-19 infections are rising sharply in South Africa which resembles the countries of South America more than those of its home continent (Figure 1, Panel A).

COVID-19 prevalence: Geographic variations and vaccination coverage. Panel A. Spread of COVID-19 in Africa vs countries in the temperate region.

There is significant different in cases including trajectories between the two regions. Numbers of total cases have been plotted against days since first reported case in respective countries (as of 5/15/2020). The spread of COVID-19 in Africa vs the rest of the tropical countries. The graph depicts different trajectories due to environmental variation. Numbers of total cases have been plotted against days since first reported case in respective countries (as of 7/07/2020). The COVID-19 pandemic has shown a markedly low proportion of cases among young people, and this could be the reason why COVID-19 infection rate is the lowest in African countries except South Africa. COVID-19 infections are rising sharply in South Africa. South Africa resembles the countries of South America more than those of its home continent. Panel B: Bacillus Calmette-Guérin (BCG) vaccination coverage map by country. Data from the World Health Organization about the BCG coverage in each country showing global status of the BCG vaccination program [**]. In contrast to the countries with no active BCG vaccination program (including the current COVID-19 epicenters such as the US, Italy, Spain, Ecuador), countries with active BCG vaccination program of African countries could be effective in the fight against COVID-19.

Source: NCBI –  COVID-19 pandemic: The African paradox

  • Published online 2020 Sep 11

References

[*] Sajadi MM, Habibzadeh P, Vintzileos A, Shokouhi S, Miralles-Wilhelm F, Amoroso A.Temperature, Humidity and Latitude Analysis to Predict Potential Spread and Seasonality for COVID-19. SSRN. 2020:3550308. PMC Analysis

[**] The BCG World Atlas 2nd Edition. Available: http://www.bcgatlas.org/index.php