Danger of the two Delta . branch variants

Scientists say that the two new descendants of Delta seem to have a survival advantage, slightly more contagious. This shows that the SARS-CoV-2 virus may still have a chance to continue to adapt to humans.

Jesse Shapiro, Associate Professor in the Department of Microbiology and Immunology, McGill University, said: 'It's hard to say what the limit is. They will continue to evolve to reach the highest level of adaptation.

The sublines, which evolved from the Delta variant, seem to have a slight survival advantage. (Artwork: Tribuneindia).

Two Delta sub-lines, known as AY.25 and AY.27, were first discovered in Canada in the spring. New cases have appeared in every province except Prince Edward Island.

AY.25 is becoming a common circulating strain of SARS-CoV-2 virus in Saskatchewan. In Ontario, AY.25 accounted for 31% of the 1,670 cases sequenced in the last 4 weeks.

The sublines, which evolved from the Delta variant, seem to have a slight survival advantage. They are growing and spreading 5% faster. This rate is lower when comparing Delta to Alpha (40-60 % faster spread).

Associate Professor Shapiro added: 'That's more or less what we expected, the virus will spread when there is a reopening, especially in the Western provinces this summer.

Art Poon, Associate Professor of Viral Evolution at Western University, explains, to understand the sublineages, SARS-CoV-2 can be considered as an old tree that always buddies when the virus evolves in different regions. different areas of the world.

The stem like a virus strain appeared in Wuhan (China). Variants of concern like Delta and Alpha, like heavy branches because they are significantly different from the original strain, speed up the spread of the virus or cause more severe disease. Sublines resemble tree branches.

"We need to discuss specific parts of the tree, especially when the branches of the tree carry mutations that affect public health," Poon said.

It's not yet clear what makes new branches a little more contagious. AY.27 has changes in the spike protein that the virus uses to enter human cells. The same mutation is present in AY.4.2 which has spread across the UK.

Associate Professor Poon said, there is still no evidence of two new types of variants that can evade immunity.

It is worth noting that branch variants have appeared in Canada for some time, at least since the beginning of April, but thanks to the efforts of the people, by vaccination and wearing masks, the number of Covid-19 cases has decreased in most. regions. In April, the number of Covid-19 cases per day was about 8,000 people, now this number has decreased to about 2,000 people.

As such, even if the branching variants of Delta do dominate, there won't be a spike in cases and things change radically.

The ability of the virus to evolve depends on the number of infections. The best way to reduce this number is to get as many people vaccinated as possible. Currently, up to 75% of Canadians have received 2 doses of the Covid-19 vaccine.