The reason why the cases are growing exponentially is due the mutation present in virus genome, these mutation increase the infectivity rate of virus along with total death count per day globally. But some sigh of relief is that many vaccines are showing good response against Covid19 and the pandemic might end in few months.
This pandemic definitely affected the economy on global scale and many third world countries are the verge of collapse and if the situation continues like this for a year or so than it will impact the world as a whole.
Mutated strains of the virus are wrecking havoc all over the world. First it was the P.1 strain from Brazil, that was causing 3,000 to 4,000 deaths per day in that country. Then came the "double mutant" strain in India (B.1.617) which is said to be 300 times more contagious when compared to the original strain. This strain (B.1.617) is believed to be mutant strain of another mutation, which was originally reported from Kent in United Kingdom. The good news is that the vaccines seems to be effective against all these strains.