Top US infectious diseases expert Anthony Fauci said on Tuesday that India's experience has taught the United States not to underestimate the potency of a second wave of the COVID-19 pandemic.

"From India's outbreak, I think there are lessons we should apply to our response here in the US,” said Dr Fauci, director of the National Institute for Allergies and Infectious Diseases and an adviser to President Joe Biden’s COVID Response team.

He told a hearing in Congress. “I think one of the important things is don't ever underestimate the situation.”

The United States remains the most COVID-infected country with more than 32.7 million positive cases and over 582,000 deaths since the global outbreak of the pandemic in March 2020.

But India has quickly caught up as number two in just over a month, having 23 million cases and almost 250,000 deaths.

Fauci said the United States learned two valuable lessons from countries like India and others afflicted with second waves of COVID: First, not to reopen too quickly from lockdowns; two, when they do reopen, to have a robust public health system that could cope with such emergencies.