Spread of the delta coronavirus variant: Africa must be on watch.

When the first cases of the Delta coronavirus variant were identified in the United Kingdom (UK) in mid-April, the country was preparing to open up from lockdown restrictions [1]. The number of infections, hospitalisations and deaths due to COVID-19 was on the decline as a result of months of lockdown and one of the world's most rapid vaccination programmes. Later in June, the variant, first identified in India, had already triggered a third wave in the UK, forcing the authorities to delay the complete reopening of society [1]. Given the startling exponential rise of the Delta variant in the UK, other countries are now beginning to brace for its impact [2]. Countries with quick access to COVID-19 vaccines, like those in Europe and North America, are hoping that the vaccination programmes would prevent the spread of the Delta variant. However, in countries where vaccine stockpiles are extremely low, specifically in Africa, the variant has the potential to wreak new waves of havoc.

The Delta variant is relatively resistant to vaccines, especially in individuals who have only received one dose [1]. A recent study published on 22 May 2021 revealed that a single dosage of either Pfizer's or AstraZeneca's vaccine decreased a person's chance of developing COVID-19 symptoms caused by the Delta variant by 33%, compared to 50% for the Alpha variant. The study also showed that a second dose of the AstraZeneca vaccine strengthened immunity against the Delta variant up to 60% (compared to 66% efficacy against the Alpha variant), while two doses of Pfizer's vaccine were 88% effective against the Delta variant (compared to 93% against the Alpha variant) [3].

The Delta coronavirus variant is by far the most threatening to countries with limited access to vaccines, specifically those in Africa, where most countries have vaccinated just under 5% of their populations [1]. Although disease surveillance in African countries is comparatively weak [4], there are indications that the variant is already causing a surge in COVID-19 cases [1]. Several sequences of the Delta variant have been identified in the Democratic Republic of the Congo, where an outbreak has overwhelmed hospitals in the capital city, Kinshasa [5]. The variant has also been reported in South Africa, Malawi and Uganda [5]. The number of COVID-19 infections has increased yet again across Africa, with the extremely contagious Delta variant moving to more countries [1]. Countries with significant economic links to India, such as those in East and West Africa, are most likely to witness a surge in cases caused by the variant. Several countries, especially in Eastern and Southern Africa, are facing unprecedented overcrowding in their hospital isolation units, rendering them incapacitated to provide adequate healthcare services [5]. Owing to the low vaccination coverage throughout the continent, the current wave of the COVID-19 pandemic in Africa is presumed to be more catastrophic than past surges. It would be an understatement to say that the current surge of COVID-19 infections and deaths across numerous African countries is alarming. The acute lack of sufficient COVID-19 vaccines throughout the continent demonstrates the gross inequity that lies in access to public health interventions. COVID-19 vaccination programmes are progressing well in high-income countries (HICs), and life is returning to normal; however, in some low- and middle-income countries, the pandemic is wreaking new waves of havoc [1]. The emergence of the Delta variant distinguishes this third wave from the first two. The increased transmissibility and mortality of the delta variant is particularly concerning, especially in a continent where fewer than 1% of the total population has been partially vaccinated [1]. Undoubtedly, a health disaster is looming. If countries had received more vaccine doses faster and earlier, this could have been prevented.

The recent situation in India is glaring, and it's a terrifying situation. Just like India, health systems throughout the continent are very fragile and at risk of becoming rapidly overburdened [4]. This is already the reality in countries such as South Africa, the Democratic Republic of the Congo, Namibia and Uganda, where shortages of intensive care unit (ICU) beds and oxygen have been reported [5]. The disparity between high-income and low- and middle-income countries when it comes to vaccine access and availability cannot be overlooked any longer. Long-term solutions include boosting vaccine development and manufacturing capacity in Africa. The recent announcement of the establishment of Africa's first COVID-19 mRNA vaccine technology transfer hub in South Africa is a step in the right direction since it will enable regional vaccine production and address the problem of severe vaccine shortages.

To successfully overcome the colossal impact of this new Delta variant, lessons must be drawn from the COVID-19 pandemic. While countries brace themselves for the Delta variant — or wish it to bypass them— Africa must be on the watch for far greater threats. Disease surveillance measures must be intensified at entrance points, and the supply, availability and access to vaccines in the continent should be prioritised. These are necessary to avoid a looming health disaster.