Sahel Medical Journal

: 2022  |  Volume : 25  |  Issue : 1  |  Page : 1--8

COVID-19 Pandemic as a mass killer and existential public health emergency in Nigeria remains unproven: A viewpoint

Emmanuel Obi Okoro1, Mumeen Olaitan Salihu2, Azibanigha S Akpila1, Ayuba O Giwa3,  
1 Department of Medicine, University of Ilorin Teaching Hospital, Ilorin, Nigeria
2 Department of Behavioral Sciences, University of Ilorin Teaching Hospital, Ilorin, Nigeria
3 Department of Jurisprudence and International Law, Delta State University, Abraka, Nigeria

Correspondence Address:
Dr. Emmanuel Obi Okoro
Department of Medicine, University of Ilorin, PMB 1515, Ilorin


Framing COVID-19 pandemic as mass killer and existential public health emergency/threat in Nigeria with 2,120 COVID-19-related deaths in over 14 months of the pandemic in the country is problematic, especially as other public health conditions kill more Nigerians annually. In 2018, for example, malaria and road traffic accident caused 97,200 and 38,902 deaths, respectively, while HIV/AIDS caused 43,000 deaths in 2019. Therefore, rushing into an extensive vaccination campaign projected to cost 540 billion naira when 76.03 billion naira was allocated for primary health services nationwide including other major immunization programs in the 2021 federal health budget could raise question of priority/effective spending. Especially with COVID-19 deaths relative to reported cases (case fatality ratio) declining to 1.30% by June 30, 2021 from 3.45% in April 2020 and daily mass deaths non-evident. Temporizing to understand how the pandemic evolves especially in jurisdictions with higher need could be cost-effective.

How to cite this article:
Okoro EO, Salihu MO, Akpila AS, Giwa AO. COVID-19 Pandemic as a mass killer and existential public health emergency in Nigeria remains unproven: A viewpoint.Sahel Med J 2022;25:1-8

How to cite this URL:
Okoro EO, Salihu MO, Akpila AS, Giwa AO. COVID-19 Pandemic as a mass killer and existential public health emergency in Nigeria remains unproven: A viewpoint. Sahel Med J [serial online] 2022 [cited 2022 Jun 27 ];25:1-8
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Full Text


Vaccinating 70% or more of people everywhere is widely accepted as the only way to end COVID-19 pandemic and fully re-open the global economy.[1],[2] In Nigeria, this means inoculating 147 million or more people to optimally diminish the risk of severe illness/death from SARS-CoV-2 – the virus that causes COVID-19. Thus far, almost four million doses of ChAdOx1 nCoV-2-19 (AZT) vaccine have been administered in an exercise proposed to be completed by 2022. Like other public immunization programs, this too involves foreign aids/loans[2],[3] and adds to escalating national debt[2],[3],[4],[5] with potential for dire social consequences.[6],[7] We aim to interrogate this approach to public health against what is possible based on accumulated and evolving evidence. This work derives from national data as widely reproduced by many global statistical platforms[8],[9]a, [9]b, [9]c, [9]d and submissions[10] to the Technical Team managing Nigeria National Response to COVID-19 pandemic between April and June 2020. A preliminary presentation of our observations was made as a keynote address to the 3rd joint Biennial conference of the University of Ilorin, Nigeria, and University of Georgia, USA, on The Challenges ahead of COVID-19, May 19–21, 2021.[11]

Emerging COVID-19 pattern

By June 30, 2021, Nigeria recorded 167,618 cases compared to millions elsewhere[8],[9]a [Table 1]. Nigeria's testing capacity is low, but mortality remains an effective indicator of COVID-19 severity, and it is difficult to conceal rapidly occurring large number of deaths locally.[12] Country differences in mortality [Table 1] could signal variability in COVID-19 severity in different populations. Moreover, deaths relative to cases (case fatality rate [CFR]) have declined to 1.30% locally from 3.45% by April 17, 2020, raising the possibility of diminishing lethality of confirmed cases even with reports of second/third “waves.” Test positivity which approximated 25% on April 17, 2020, at the height of the first ”wave” has declined to 0.65% as of June 27, 2021, suggesting the prospect of a dwindling disease transmission.[8],[9]a{Table 1}

Therefore, projecting SARS-CoV-2 as a MASS KILLER and existential public health threat[13],[14] based on 2120 COVID-19-related deaths within over 14 months of the pandemic even after doubling this mortality figure to 4240 to correct possible undercounting[15] is problematic, especially when other conditions kill more people locally than COVID-19 annually [Figure 1].[16],[17],[18] Juxtaposing this death number [Table 1] with natural mortality of 27,912; 25,124; and 22,359 for years 2014, 2015, and 2016, respectively,[19] could suggest a dominant disease behavior of SARS-CoV-2 with fewer tendencies for severe illness/mass casualty in Nigeria as previously submitted.[10]

Contextually, therefore, rushing to expend over 540 billion naira (N) on COVID-19 when 76.03 billion (N) was federally allocated for primary health services nationwide including capital expenditure on existing immunization programs[20],[21],[22] raises question of priority/effective spending. Especially with HIV/AIDS and Tuberculosis killing more Nigerians annually [Figure 1] receiving 1.7 billion and 59 million naira respectively, in the 2021 approved and supplementary budgets.[22],[23],[24],[25]{Figure 1}

COVID-19 vaccination and Nigeria

First, the proposal for the need for over 70% vaccination coverage to control COVID-19 pandemic aligns with available knowledge at the time.[1],[26] Since then, accumulated data[9a, 27] show heterogeneity in disease behavior [Table 1] that could impact vaccination requirement in different jurisdictions. Specifically, following initial fear of catastrophe, subsequent modeling[28],[29] indicates Africa as exhibiting a flatter (≥50% lower) risk gradient for adverse COVID-19 outcomes consistent with local experience [Table 1] thus far. Second, the age structure of the Nigerian population [Figure 2] makes attaining 70% or greater vaccination coverage technically impossible with no vaccine currently licensed locally for use in people below 18 years who constitute 48.4% of the population.[9b,19] Third, though frontline vaccines are incredibly effective (≥90%) against severe COVID-19/death[30] so too seems natural immunity (83%–100%) following exposure to SARS-CoV-2 infection.[31],[32],[33],[34]{Figure 2}

A preliminary report from Israel, for example, indicates that vaccination was 92.8%, 94.2%, and 94.4% effective against re-infection, hospitalization, and severe illness versus 94%, 94.1%, 96.4%, respectively, in those previously infected/recovered.[35] These reports raise a perplexing question of the need to vaccinate individuals previously infected as also hinted in one early phase 3 clinical trials which formed the basis of its market authorization.[30] This question is of particular relevance to the Nigerian situation where other public health conditions kill more people compared to SARS-CoV-2 infection [Figure 1] thus far and has also caused fewer deaths than elsewhere [Table 1]. This is also against the possibility that many have already been exposed to SARS-CoV-2 infection even without them knowing it. Specifically, data collected 3–7 months into COVID-19 pandemic in Nigeria showed that 1 in 5 people tested positive to SARS-CoV-2 antibodies in states surveyed.[36],[37] It is striking that Nigeria has >20% SARS-CoV-2 antibody positivity and comparatively lower mortality compared to 0.6%, 1.97%, 4.5%, and 4.6% seropositivity in four major European cities/hotspots[38] that were experiencing alarmingly high COVID-19 deaths at the time. Since these observations during the first wave in 2020, COVID-19 deaths relative to “cases” in Nigeria has remained mostly flat or trending downward including during rainy seasons when people congregate more indoors and newer SARS-CoV-2 lineages circulating.[9]d,[39],[40]Coincidentally, blood samples acquired in 2018 as part of a nationwide HIV/AIDS indicators/impact survey and re-tested in 2020 revealed 17% cross-reactivity to SARS-CoV-2.[41] This suggests that there were antibodies of the same/similar activity in the Nigerian population before the 2019 declaration of COVID-19 pandemic.

Therefore, if pre-vaccination level of SARS-CoV-2 antibodies reflects state of population immunity, then differences in this parameter in different groups makes it less likely vaccination requirement to reach herd immunity threshold can be the same everywhere. In this regard, Nigeria has the advantage of groups 40 years and younger constituting 80% of the 3population versus 49.2% of such groups in UK population [Figure 2].[9b] In addition, those ≥65 years and ≥ 50 constitute 2.7% and 9.7% correspondingly versus 18.8% and 36.1% respectively in the UK [Figure 2].[9f] This “youth bulge” of Nigeria, particularly young adults, mainly spread SARS-CoV-2 even without becoming ill themselves.[9a, 42] In this way could be unknowingly “immunizing” the population towards herd immunity threshold as facilitated also by widespread non-compliance with masking, physical distancing, crowd size limitations, movement restrictions, etc., imposed nationwide.[43],[44] If this is true, then it is happening without the high cost of envisaged severe illness/mass casualty and health system collapse [Table 1]. This possibility of rising community resistance to SARS-CoV-2 from natural exposure is further strengthened by reports of over 40% SARS-CoV-2 antibodies positivity in otherwise healthy young adults during the first wave in 2020 when this averaged 23.3% in their European counterparts[38],[45],[46] suggesting extensive community transmission. Of note, while SARS-CoV-2 infections occur in children,[47],[48] severe COVID-19/death remains predominantly a disease of 50 years and older in Nigeria among whom chronic conditions that amplify the risk of poor outcomes are common.[42]


We propose that targeting this vulnerable group (50 years and older) which constitutes 9.4% of the Nigerian population with high coverage rather than 70% or higher[9b] [Figure 2] could be more cost-effective. In addition, it will prevent the high death tolls, hospitalizations, and lockdowns. Ring vaccination[49] during outbreaks can further enhance this strategy. Furthermore, SARS-CoV-2 antibodies pretesting at point-of-inoculation could lower vaccination cost further by identifying those with prior infection for whom a single dose seems a booster dose[47],[48],[49] in the two-dose–inoculation schedule Nigeria currently operates.

SARS-CoV-2 variants and Nigeria

There are reports that SARS-CoV-2 lineages can evade preexisting immunity.[50],[51],[52] Compared to other countries, this may not be a serious issue in Nigeria given the observations in more than 14 months of the pandemic [Table 1]. The control of COVID-19 cannot be limited to one-size-fits-all policy of vaccination coverage given the differences in SARS-CoV-2 antibodies prevalence in different population groups/jurisdictions, geo-epidemiologic variations in disease severity, and compelling data showing natural immunity as comparable to vaccine-induced protection.[30],[31],[32],[33],[34],[35],[53],[54] Furthermore, issues of supply chain and vaccines hoarding are currently undermining global vaccination efforts.[55],[56],[57] Consequently, Nigeria was affected and had to pause its vaccination campaign even when less than 1% of the population was fully inoculated.[9c] Paradoxically, countries with vaccine advantage have seen cases raise gain-third/fourth wave driven mostly by new lineages, particularly the delta variant.[9c] Indeed, updated vaccines and booster doses are being recommended as countermeasures against what is now clearly a constantly changing virus.[9]c, [50],[51],[52],[57]

This raises some troubling issues if this evolving scenario becomes the norm, especially for nations with struggling economies. Nigeria has over 206 million people[9b, 19] [Figure 2], and the cost involved in frequent inoculations could spiral out of control and become unsustainable locally. Dwindling government revenue and a poverty rate of over 40% can further limit domestic revenue mobilization for self-sufficiency.[3],[58] Nigeria's COVID-19 vaccination campaign predicated on global solidarity and equitable vaccines supply, is faltering, due in part to intense nationalism and “greed “according to the World Health Organization.[55],[56],[57],[59] One potential consequence of the vast majority (>98%) of the population being unvaccinated is the risk of deadlier lineages emerging through selection pressure. This could turn what is so far an otherwise less severe form of SARS-CoV-2 infections [Table 1] and [Figure 1] into a pandemic of the unvaccinated observed in the USA and other nations.[9b] Fortunately, Nigeria appears to have factors such as less disease severity, youthful population, and early and widespread SARS-CoV-2 transmission that is probably accelerating population immunity through natural infection, often asymptomatic or mild.[8],[9]b,[42]

However, Nigeria's record of embracing expensive interventions made in the image of other people's priority in a one-size-fits-all approach when cheaper alternatives are available could offset this advantage.[60],[61],[62],[63],[64],[65] Sometimes interventions for non-diseases become national best practice in total disregard of expert/autopsy data, health policies and legislations, as in universal lowering of elevated cholesterol without clinical atherosclerotic disease.[63],[64],[65],[66],[67],[68],[69],[70],[71] Nonetheless, reaching herd immunity through vaccinating 70% or more of the global population is useful in the control of COVID-19 and returns to normal economic life. Doing so is also about lucrative gains for organizations operating in health systems to create public good for profits.[72],[73] Incidentally, at a time of similar vaccines shortage, ring vaccination invented in Nigeria made it possible to effectively utilize what limited doses there were then to eradicate smallpox globally beginning locally.[49] There is little to no reason why this cannot happen again, especially with evidence[47],[48],[74],[75],[76],[77] indicating vaccinating adults also protect children/teenagers who rarely get severely ill or die from SARS-CoV-2 infection and constitute nearly 40% of the Nigeria population[9]a,[9]b,[19],[42],[47],[48] [Figure 2].

Lockdowns and social desperation

Beyond loss of lives/livelihoods, choices countries make on how best to respond to COVID-19 pandemic in the context of their own peculiarities is less well documented. Given the level of poverty in Nigeria, it is almost inevitable people go out daily to work or in search of jobs to support themselves and families. Limiting the opportunity to do so through lockdowns tipped Nigeria's fragile economy into recession precipitating pervasive hunger, in one instance, leading to widespread looting and rioting-alias # ENDSARS.[6],[7] Young people were mostly affected and have had to make enormous sacrifices to protect the most vulnerable in society. To also leaving them an ever-increasing national debt[2],[3],[4],[5] as inheritance that could limit their future when a different vaccination approach at a lower cost also capable of keeping their fathers, grand and great-grandfathers generations safe is possible even if SARS-CoV-2 becomes endemic and keep mutating is difficult to justify.

More so when the present course of action involves globalization that puts other people's priorities ahead of local needs and circumstances in the name of solidarity.[56]

Besides, inadequate vaccination from supply shortages driven by vaccine nationalism could in theory as earlier indicated result in the emergence of more transmissible lineages with devastating consequences on the unvaccinated as unfolded even in countries like the US and Israel with 60% or more coverage.[9a-d] Indeed, one real-life data[75] released in late July indicated 74% of all re-infections with the delta variant occurred in those fully vaccinated with almost 80% of those infected symptomatic and only a few requiring hospitalization and no death recorded. Even so, frontline vaccines remain largely protective against severe disease from all SARS-CoV-2 lineages so far. One recent data from England[79] showed BNT162b2 was 93.7% (95% confidence interval [CI]: 91.6–95.3) and 88.0% (95% CI: 85.3–90.1) protective against symptomatic re-infection by alpha and delta variants, respectively, and for ChAdOx1 nCoV-2-19 (AZT), the figures were 74.5% (95% CI: 68.4–79.4) and 67.0% (95% CI: 61.3–71.1) against alpha and delta variants, respectively. While these figures suggest a decline in effectiveness against the delta variants their protection against severe disease /death from the alpha variant (Wuhan) [62.1-90% AZT, 95% BNTb2 and 94.1% Moderna]; remain robust comparable to protection [93%-99%] from natural immunity observed in many large cohort studies.[28],[29],[30],[31],[32],[50],[51] Further, a growing body of research also show a single dose of AZT or BNT2b2 vaccine in previously infected individuals generate higher protection against all circulating variants compared to those fully vaccinated who are more likely to require a booster dose to maintain vaccine-induced protection.[47],[48],[49]

These observations are consistent with the possibility that natural immunity protects against SARS-CoV-2 re-infection, sometimes more so even in jurisdictions experiencing high COVID-19 deaths [Table 1].

One recently published cohort study from Qatar[77] showed similar protection against re-infection from all variants including the delta lineage in fully vaccinated people and in previously infected individuals; the RR values being 0.22 [95% CI 0.17-0.28] in vaccinated groups versus 0.26 [95% CI 0.21-0.34] in those previously infected. It seems the case that subsequent SARS-CoV-2 infections appear generally less severe in the presence of preexisting immunity whether generated by vaccine or natural infection. In other words, a healthy immune system appears to protect robustly against re-infection/severe disease to a similar extent as observed with many vaccines currently licensed for emergency use. It is our contention that feeding these observations into policy options available to countries like Nigeria with comparatively low COVID-19 mortality but lacking the economic power to compete with others for supplies could achieve more with less.


For one, the highly contagious delta variant is circulating in Nigeria where over 98% of the population remains unvaccinated. However, cases/deaths have not grown quickly and exponentially as experienced in India.[9a-d] Nonetheless, if substantial population immunity already exists as we believe; then, subsequent disease pattern including deaths relative to cases (CFR: 1.3%) should remain more or less as in [Table 1], even if the delta variant becomes the dominant lineage. Indeed, although SARS-CoV-2 constantly mutates just like influenza virus, neither flu vaccination nor annual boosters are national priorities compared to populations with higher COVID-19 mortality [Table 1]. Significantly, available data[78],[79],[80],[81],[82] indicate clinical influenza disease in Nigeria is predominantly a condition of under-fives rather than of the elderly (65 years or older) who account for over 70% of influenza deaths. Statistically modeling also suggest such deaths to be 250% less in tropical Africa compared to colder climates probably due to variations in local disease behavior and differences in demographics.[78],[79],[80],[81],[82] This striking parallel with COVID 19 is also against a background of all year round transmission of the deadlier flu pandemic lineage in Nigeria which has not become a reservoir of constant mutations that threatens others, despite being largely a population unvaccinated for the flu.[84],[85],[86] Co-incidentally, flu incidence/severity is almost suppressed everywhere[80, 83] since the advent of COVID-19 raising the possibility it could override flu as the dominant seasonal pandemic.


The evidence of COVID-19 as existential public health emergency/threat in Nigeria to warrant extraordinary public expenditure for mass vaccination at this stage of the pandemic over and above more pressing public health conditions is simply unavailable. Temporizing therefore to understand how the pandemic is evolving particularly in jurisdictions with higher needs could be cost effective especially as mass casualty and a collapsed health system remain non-evident.


We appreciate with gratitude the criticisms and suggestions of the reviewers which were helpful in improving the quality of the text.

Financial support and sponsorship

This work was self-funded.

Conflicts of interest

There are no conflicts of interest.


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