After the virus binds to ACE2, the next step is to fuse with the cell. This process starts with the enzyme in the host cell cutting the spikes at two different locations. This process is called lysis. This kick activated the fusion machine. If binding is like a key to a lock, splitting is like a key turning a bolt. Vineet Menachery, a virologist at the University of Texas Medical Division, said: “If you don’t cut in two places, the virus cannot enter the cell.”
One of the mutations present in Delta actually occurs in one of these cleavage sites, and A new study that has not been peer-reviewed This indicates that the mutation does enhance cleavage. Menahari, who was not involved in the study, said that he has replicated these results in his laboratory. “So the virus is more likely to be activated,” he said.
It is not clear whether this will improve transmission capacity, but it can. Menachery said that when scientists delete these cleavage sites, the spread and pathogenicity of the virus decreases. Therefore, it makes sense that changes that promote division will increase transmission.
Delta’s ability to evade the body’s immune response may also help promote transmission. Immune evasion means that more cells are infected and produce more virus, which may make people with the virus more likely to infect other people.
But the vaccine is still effective
The good news is that vaccination can provide strong protection against the delta virus.A kind New research on public health in the UK It shows that the Pfizer-BioNTech vaccine is 88% effective in preventing symptomatic diseases caused by Delta in the fully vaccinated population. The AstraZeneca vaccine provides slightly less protection. The effective rate of two shots on the variant is 60%. However, the effectiveness of a single dose of the vaccine is much lower-only 33%.
In any case, in the United States and the United Kingdom, only about 42% of the population has been vaccinated. Part of the reason for the surge in the virus in India is the rapid spread of Delta, with only 3.3% of the population achieving full vaccination.
At the press conference, Fauci urged those who had not been vaccinated to get the first shot and reminded some vaccinated people not to skip the second shot. The Biden administration hopes that at least 70% of the population will be partially vaccinated by July 4. In the UK, Delta quickly replaced Alpha as the main strain, and cases are now on the rise. “We can’t let this happen in the United States,” Fauci said.