Scientists hope the vaccination will mitigate a possible fourth surge.

On Tuesday, President Biden postponed his vaccination schedule for two weeks and urged states to question every American adult by April 19. All states have already achieved or expect to achieve this goal after he originally asked them to do so by May 1st.

The variant B.1.1.7 first arrived in the USA last year. In February, a study that analyzed half a million coronavirus tests and hundreds of genomes predicted that this variant could prevail in the country in a month. At the time, the CDC was struggling to sequence the new variants, making them difficult to track.

However, those efforts have improved significantly over the past few weeks and will continue to grow, in large part due to a $ 1.75 billion funding for genome sequencing as part of the stimulus package that Mr Biden put into the Law. In contrast, the UK, which has a more centralized health system, launched a heavily promoted sequencing program last year that allowed it to track the spread of variant B.1.1.7.

“We knew this was going to happen: this variant is much more communicable, much more contagious than the parent strain, and that obviously has an impact,” said Dr. Carlos del Rio, Professor of Medicine and Infectious Disease Expert at Emory University. The B.1.1.7 strain not only spreads more efficiently, but also appears to cause more severe disease “so you get a double blow”.

Perhaps even more worrying is the emergence of the virulent P.1 variant in North America. First identified in Brazil, it has become the dominant variant in that country, helping to bring its hospitals to the breaking point. In Canada, the P.1 variant emerged as a cluster in Ontario and then closed the Whistler ski area in British Columbia. On Wednesday, the Vancouver Canucks of the National Hockey League said at least 21 players and four employees had been infected with the coronavirus.

“This is a vivid reminder of how quickly the virus can spread and the serious effects it can have on even healthy, young athletes,” the team’s doctor Jim Bovard said in a statement.