All the entry regulations in reference to the Corona Vaccination are lifted in the USA at 11 May. This will allow Djokovic to play at the US Open and chase another Grand Slam title. However, it is not certain whether he will remain number 1 in the world rankings. In any case he will not be allowed to play at the tournaments in Indian Wells and Miami. So his pursuers have two possibilities to get closer to him or even to regain spot number 1.
This is amazing news for Novak Djokovic and now he has a chance again to attack all 4 grand slams to win them in a year. With the level he is playing he might win them all. Only the French open might be a big problem for him due to him playing on clay where he isnt the best.