The Delta form of the coronavirus, which causes Covid-19, is the fastest, strongest, and most dangerous version of the virus, according to scientists, clinicians, and public health officials. Even as nations eliminate bans and open their borders, it is changing up public perceptions of the disease. Vaccine protection against severe illnesses and hospitalizations caused by any coronavirus type is still quite excellent. According to 10 prominent Covid-19 specialists interviewed, the people who would be most at risk are actually unvaccinated.