New York, Apr 13 (IANS): If we believe billionaire philanthropist Bill Gates, very few countries will get 'A-grade' for new coronavirus response when it comes to understanding the scale of the damage COVID-19 could do.

Speaking to BBC, Gates said several countries have failed on providing proper healthcare and there will be a "post-mortem" when the disease is tackled.

"We are in uncharted territory due to a lack of investment and preparation for such a pandemic," Gates said.

The number of COVID-19 cases in the US topped 550,000 on Monday, according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University.

Worldwide, over 18 lakh people have been infected, with more than 1.14 lakh deaths.

Gates has announced his foundation is paying for the construction of facilities that will manufacture seven promising coronavirus vaccines and the best two vaccines would be picked up for final trials.

According to the scientists, a vaccine may take up to 12-18 months after successful human clinical trials.

Gates has also called upon donor governments to help low- and middle-income countries prepare for this "pandemic", in addition to helping their own citizens respond.

The Bill & Melinda Gates Foundation in February announced that it would immediately commit up to $100 million for the global response to the novel coronavirus.