Overwhelmed hospitals in London, a dominant new variant in South Africa, and growing concern around the world.
Since December, several major variants of the new coronavirus have been closely monitored by global health authorities, including by the World Health Organization (WHO).
Because even if the phenomenon of mutation of a virus is common, some of these new variants are suspected of being more transmissible.
“The more the Covid-19 spreads, the more likely it is that it will still evolve.
It should be noted that the transmissibility of certain variants of the virus seems to be increasing ”, declared Tedros Adhanom Ghebreyesus, the director general of the WHO.
What is known about these variants reported in the UK, South Africa, and more recently Japan?
We take stock.
In the UK, a variant up to 70% more contagious
What contagiousness?
As a recent article in the medical journal The Lancet recalls, the variant detected in the UK in September (but reported only in December), referred to as 'VOC 202012/01', can be up to around 70 % more contagious, according to several preliminary studies carried out across the Channel.
“In September 2020, this variant represented only one in four cases of new Covid-19 diagnoses.
In mid-December, this rate had risen to nearly two-thirds of new cases in London, ”we can read.
There is no evidence yet that this strain causes more serious illness.
It also remains to be seen whether this variant directly leads to an increase in cases, which was notably suggested by Boris Johnson shortly before the United Kingdom's re-containment.
“We do not know what the causal relationship is between the emergence of the variant and the form of the epidemic, whether there was an epidemic outbreak which favored the variant, or whether it favored the outbreak.
It's the chicken and the egg, ”recalls Professor Jean-Michel Pawlotsky, virologist and head of the biology department at Henri-Mondor hospital in Créteil (Val-de-Marne).
What presence?
The cases of this variant continue to be newly reported around the world, especially in Western Europe (from France to Denmark via Germany) but also in Russia, India, China, Australia, as well as in the United States and Mexico.
The origin of this variant, for the WHO, is so far "unclear".
Some British scientists are studying the track of a mutation that occurred in a patient with a more fragile immune system who would have suffered from Covid-19 for a longer period, according to the journal Science.
In South Africa, a new dominant variant
What contagiousness?
The variant detected in South Africa is also more contagious.
"It is spreading faster," explains South African epidemiologist Salim Abdool Karim.
"In the two provinces where it predominates, it took 40 to 50% less time to reach 100,000 cases," said the professor, a member of the South African government's advisory committee on the epidemic.
Consequence: "Hospitals fill up faster, intensive care beds fill up faster and respirator shortages are more serious", he summarizes.
Morning essentials newsletter
A tour of the news to start the day
Subscribe to the newsletterAll newsletters
On the other hand, like the British variant, there is no evidence that the South African variant causes more serious forms of Covid-19.
A question is however raised by the properties of certain mutations of this variant, which allow it "to bind better to a human cell", adds Pr. Abdool Karim.
This may require adaptation of the vaccines, as is done every year for the flu.
READ ALSO>
Coronavirus: is the South African variant at risk of escaping the vaccine?
What presence?
This variant, named "501Y.V2", was detected in December, and has become the dominant variant in the country.
According to Salim Abdool Karim, it has been detected, in total, in about fifteen countries, such as France, the United Kingdom, Israel, Denmark, or even Canada.
To prevent this variant from circulating, the South African President, Cyril Ramaphosa, has just announced the closure of the country's land borders for one month, in order to limit the transmission of the variant abroad.
In Japan, cases imported from Brazil
What contagiousness?
For now, Japan does not yet know if this variant is more contagious or more dangerous than the others circulating in the world.
This variant will be isolated, to be analyzed "further", explained an official in the Japanese Ministry of Health.
“It could take between several weeks and several months […] so it is difficult at the moment to say when we can give details” on this variant, he added.
The Japanese National Institute of Infectious Diseases, however, clarified that the new variant discovered in Japan had similarities with those identified in the United Kingdom and South Africa.
What presence?
At this stage, the virus has been detected in four people, two adults and two children, who arrived from Brazil.
One of those people, a man in his 40s, was later hospitalized with difficulty breathing, while a woman and one of the two children, a boy, developed moderate symptoms.
The fourth person, a girl, is asymptomatic.
The appearance of variants is not a new phenomenon, remind the specialists interviewed.
“We can expect new variants to appear quickly over time, and in our globalized world, no one will be able to escape them.
The more transmissible D614G variant, for example, was the dominant variant in Europe, and South Africa caught it, ”explains Salim Abdool Karim.
READ ALSO>
Covid-19: in Ireland, the epidemic is exploding like nowhere else
To combat these variants, the rules remain the same, according to Professors Abdool Karim and Pawlotsky: application of barrier gestures, screening, tracing and isolation of cases.
"The difference is that you have to prepare your health services and better guide vaccinations," suggests the South African professor.
Cases of these variants are going to happen quickly, and furiously.
"