Coronavirus that causes Covid-19 has already mutated a lot since it appeared in late 2019 in China. In addition to the original source, known as “wild” that will spread throughout the world by 2020, more infectious variants, sometimes more dangerous or even that may partially escape vaccination, have emerged. The World Health Organization (WHO) and governments around the world are therefore closely monitoring the appearance of these variants in order to adapt the response to the pandemic.
In Africa, because there are few laboratories equipped for genome sequencing, ie. can read the genetic code of the virus, the WHO has organized a network of reference laboratories that receive samples from across the continent to monitor the appearance of these mutant viruses. “So far, 24,000 samples have been sequenced in Africa,” explains WHO Africa Director-General Dr Matshidiso Moeti. “We know that this is not enough and that we must quickly increase the pace” due to the fact that some variants increase the power.
According to data already collected by the WHO, the Alpha variant, also known as the English variant, is identified in 32 African countries. It is found mainly in the northwestern and central part of the continent. The beta variant, which appeared in South Africa, is found in 27 African countries. It is reported especially in southern countries. “These two variants are more transmissible than the wild virus,” explains Dr Moeti, but the Delta variant, the Indian variant, is even more transmissible, according to her. So far, it has been recorded in 16 African countries.
In South Africa, as the country goes through a third wave of Covid-19 even more violently than the previous one, it has surpassed the local variant Beta and has become the majority. In Uganda, it now represents 97% of the tests performed and 84% in the DRC.
“It is the most contagious variant to date. It can be up to 60% more transferable than the other variants, says the WHO’s head in Africa. Preliminary observations suggest that the Delta variant is linked to more severe and prolonged forms of Covid-19. “
New varieties in Africa
“Higher portability means more cases, more hospital stays and a greater risk of overwhelming health systems,” recalls Matshidiso Moeti.
In addition to these three variants, which the WHO considers “worrying”, other variants are emerging on the continent. These are variants that are said to be “of interest”, “to follow”, because they are spread in several countries and may have the same mutations that are found in the “worrying” variants. They still need to be evaluated in more detail.
First, the Eta variant, also known as the Nigerian variant, although its origin is not clearly proven. Appeared in December 2020, “it is now present in 21 to 25 African countries, and has become the third most common variant on the continent, after Alpha and Beta”, describes Dr. Nicksy Gumede-Moeletsi, virologist at WHO Africa. “We are also beginning to observe the Kappa variant, an underline of the Indian variant [variant Delta], observed in three countries on the continent. Finally, the Epsilon variant, known as the California variant, has been observed in two African countries. “
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Effective vaccines
All viruses mutate, so the appearance of the variants is normal. Fortunately, the vaccines currently on the market seem to be effective against these different strains of coronavirus. Although they do not necessarily prevent all infections and mild forms, studies conducted in countries where vaccination is already very advanced show that vaccines limit the number of serious forms and hospital stays, according to WHO experts. By slowing down the spread of the virus, vaccines also slow down new forms of the virus and thus dangerous variants.
“Vaccination is clearly a solution to end this pandemic yet just over 1% of Africans are fully vaccinated», Regrets Matshidiso Moeti, who also reminds of the importance of barrier gestures.
–What is a variant?
All viruses mutate over time, especially when they circulate abundantly in the population. When multiplied, small errors appear in the genetic code of the virus. These are called mutations, which can change the properties of the virus, or on the contrary do not lead to any change. There are actually a variety of varieties, but only a handful have acquired more dangerous properties. It is these variants that are monitored by researchers and authorities.
–Understand the different categories of variants
According to WHO classification, variants are denoted by a letter of the Greek alphabet and may be of “interest” or considered to be of “interest”. Variants “to look at” or “of interest” are those that are spread within a population or that are discovered in several countries. This is the case with the Epsilon variant, which appeared in the United States in March 2020 for example (the California variant), or Theta, which was discovered in the Philippines in January 2021. In Africa, the Eta variant, the Nigerian variant is part of this category .
Variants are considered “worrying” when studies show that they are also more easily infected, that they are more virulent or that they avoid drugs, vaccines or detection through diagnostic tests, for example. The alpha variant, also known as the “English” variant, spreads faster than the wild strain and has replaced it in many countries. The beta variant, also called the “South African” or Gamma variant, the “Brazilian” variant, has particular mutations that make it less susceptible to vaccines. The Delta variant, which came from India, is still the most contagious variant, “up to 60% more transmissible than the others”, according to experts.
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