The WHO had last month classified the entire variant as “of concern”, but said on Tuesday that only one sub-lineage should now be considered as such.
“It has become clear that more risks to the public are associated with B.1617.2, while lower rates of transmission have been observed with the other sub-lineages,” WHO said in its weekly pandemic update.
B.1617.2 remains a concern, along with three other variants of the virus, which are considered more dangerous than the original version because they are more contagious, deadly or because vaccines may not offer protection against them.
On Monday, the WHO assigned Greek letters to the scientific names of the different variants, such as Alpha, Beta and Gamma. This initiative aims to avoid “stigmatising and discriminatory” names for the countries and territories where they have appeared.
“We continue to observe a clear increase in transmissibility and a growing number of countries reporting outbreaks linked to this variant,” notes the WHO, which considers it a “priority” to conduct “new studies” on its impact.
A new variant, reported on Saturday by health authorities in Vietnam, appears to be a variant of Delta, Dr Maria Van Kerkhove, the agency’s COVID-19 technical officer, said on Tuesday.
“We know that B.1617.2 has increased transmissibility, which means it can spread more easily between people,” she said.
The B.1617.1 subline has been downgraded to the category of “variant of interest” and named Kappa.
B.1617.3 is no longer considered to be of interest by the WHO and has not been assigned a Greek letter due to its relatively low occurrence.
The two most vaccinated countries in the world, the UK and Israel, are seeing their infection and hospitalization rates rise dangerously.
The UK has gone from 1984 cases on 6 May 2021 to 11,000 cases on 22 June, and in Israel, where there were no more cases as of 15 days ago.
In Israel, the number of new cases rose to 90 on 23 June. More worryingly, 40% of these new cases are from people who have received their two injections with the vaccine.
There is strong talk in Israel of reintroducing masks in enclosed areas.
There are now more than 10,000 new cases a day in the UK, compared to a plateau of 2,000 daily cases in April and May. The Delta variant now accounts for 99% of new cases.
Yet the country has one of the highest vaccination rates:
46% of the population has received two doses
17% have received a single dose
37% of the population has not received any vaccination against COVID-19.
The Delta variant, first detected in India in October 2020 – and responsible for the huge wave in that country in the spring – is now present in over 80 countries.
It was only on 16 April that the UK confirmed its first cases of the Delta variant. As of 18 June, two months later, 99% of new cases are linked to this variant.
In the United States, the proportion of cases linked to the Delta variant has increased from 6% to 30% in a fortnight. Nearly 100% of the cases detected in Russia and Portugal are now from the Delta variant.
In Canada, the first cases linked to the variant were detected at the end of April.
According to data collected by CBC, just over 2,400 cases have been directly associated with this variant as of 21 June 2021. The number of cases has doubled in the space of 10 days.
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More than 30% of new cases in Ontario are of the Delta variant. According to experts, this variant could become dominant by the end of July.
Is this variant more dangerous?
This variant is considered a double mutant because it carries two mutations of concern in key areas of the SARS-CoV-2 spike protein. One of these mutations has been observed in the South African and Brazilian variants and reduces the effectiveness of vaccines and increases the risk of reinfection. The second mutation, which increases transmission, has also been found in California.
The Delta variant, and potentially the others that will follow, are clearly more contagious and potentially more virulent,” says Benoît Masse.
One study shows that the Delta variant is 6.8 times more infectious than the original SARS-CoV-2 strain. If it was the Delta variant that hit Quebec in March 2020, it would have been much more catastrophic. Definitely more,” says Masse.
According to British data, hospitalizations are also on the rise. We don’t yet know how much more deadly the variant really is. Is it [fewer deaths] because those who are infected are young people who are generally healthier and will get off easier? However, the more infections there are, the more hospitalizations and deaths there are likely to be.
Are the symptoms the same?
According to early UK data, headache, sore throat and runny nose are the most commonly reported symptoms of the Delta variant.
But the classic symptoms of COVID-19 – cough, fever and loss of smell – are still present. Loss of smell seems to be somewhat less common with this variant.
There is a long list of symptoms associated with the disease:
loss of appetite
Do vaccines work?
This variant seems to affect more people who have received one or no dose of the COVID-19 vaccine. But there are also cases of reinfection and cases in people who have received two doses of vaccine.
The good news is that the vaccines appear to be effective against the Delta variant, especially in preventing severe cases of the disease. However, one dose is not enough.
Effectiveness in preventing the disease (New Window) caused by the Delta variant :
Pfizer-BioNTech: 33%, 88% after two doses;
AstraZeneca: 33% after one dose; 60% after two doses.
Effectiveness in reducing hospitalizations (New Window) caused by Delta variant :
Pfizer-BioNTech: 94% after one dose, 96% after two doses;
AstraZeneca: 71% after one dose, 92% after two doses.
Since the Delta variant is much more transmissible, experts believe that a 90% vaccination rate would be required to control this variant.
Dr Shapiro adds that sewage testing is an excellent method of tracking the spread of the virus even if people don’t go for testing. We can see if there’s an outbreak and catch cases and contacts, without necessarily shutting down everything.
It is important for countries that are not or only marginally affected by this Delta variant to prepare for the scenario of a major new wave in order to avoid the unfortunate events of Spring Autumn 2020 and Spring 2021, as the world’s populations are no longer ready for widespread containment.