SYDNEY (REUTERS) - Global coronavirus cases are expected to pass 30 million on Thursday (Sept 17), according to a Reuters tally, with the pandemic showing no signs of slowing.

India was firmly in focus as the latest epicentre, although North and South America combined accounted for almost half of the global cases.

Global new daily case numbers reached record levels in recent days and deaths neared one million as the international race to develop and market a vaccine heated up.

The official number of global coronavirus cases is now more than five times the number of severe influenza illnesses recorded annually, according to World Health Organisation (WHO) data.

Around the world, there have been almost a million deaths, considered a lagging indicator given the two-week incubation period of the virus. That has well exceeded the upper range of 290,000 to 650,000 annual deaths linked to influenza.

India on Wednesday became only the second country in the world, after the United States, to record more than five million cases.

The South Asian nation, the world's second-most populous country, has been reporting more new daily cases than the US since mid-August and accounts for just over 16 per cent of global known cases.

The US has about 20 per cent of all global cases, although it has just 4 per cent of the world's population. Brazil, the third worst-hit country, accounts for roughly 15 per cent of global cases.

It took 18 days for global cases to surge from 25 million to more than 30 million. It took 20 days for the world to go from 20 million to 25 million and 19 days to go from 15 million to 20 million.

The global rate of new daily cases is slowing, reflecting progress in constraining the disease in many countries, despite a few big surges.

Health experts stress that official data almost certainly under-reports both infections and deaths, particularly in countries with limited testing capacity.

The race to develop and bring to market a novel coronavirus vaccine has grown increasingly frenetic in recent weeks with about 200 candidates in development globally.

US President Donald Trump has said his country could have a vaccine ready for distribution before the election on Nov 3, while a Chinese health official this week said China may have a vaccine ready for public use as early as November.

While the trajectory of the coronavirus still falls far short that of the 1918 Spanish flu, which infected an estimated 500 million people, killing at least 10 per cent of them, experts worry the available data is underplaying the true impact of the pandemic.