But WHO director general Tedros Adhanom Ghebreyesus on Monday warned about becoming overly optimistic.

"There is a huge disconnect growing where, in some countries with the highest vaccination rates, there appears to be a mindset that the COVID-19 pandemic is over while others are experiencing huge waves of infection," he said without providing specific weekly data.

He said the pandemic would not be over until it had been beaten everywhere and called on pharmaceutical companies to show more flexibility in the interest of getting more doses delivered to poor countries now and not to wait until the second half of this year or even 2022.

Tedros also said manufacturers should release countries from contracts that prohibit them from transferring doses to others if the country's goal is to donate the medicine to other countries.

COVAX, an initiative started by the WHO to distribute vaccine doses to poorer countries, has so far helped to bring 65 million doses to 124 countries.

Tedros says he hopes to have distributed 190 million doses by the end of June.

India on Monday began distributing a newly developed drug to treat COVID-19 symptoms which reportedly reduces patients' dependence on oxygen and hastens their recovery.

The drug 2-deoxy-D-glucose (2DG) was developed by a laboratory of India's Defence Research and Development Organisation (DRDO) and Hyderabad-based pharmaceutical company Dr Reddy's Laboratories.

The first batch of the drug was released by Indian Defence Minister Rajnath Singh and Health Minister Harsh Vardhan in the Indian capital and will be initially used in hospitals in the city.

Some experts have, however, questioned the efficacy of the new drug, saying not enough evidence has been published from the stage two and three clinical trials.

A variation of 2DG has been used earlier on an experimental basis to treat certain strains of cancer but has not been approved yet for that purpose, molecular biologist Rakesh Mishra said.

Mishra, who has been involved in the development of the new drug, said it blocked the ability of the virus to multiply in certain cells.

A significant percentage of patients in the trials could be taken off oxygen support after taking two sachets.

Mishra said the drug was meant to treat those in early stages so that they their condition did not turn more serious.

The formula, known as 2DG, went through year-long second and third stage clinical trials and was approved by the Drugs Controller General of India (DCGI) on May 1.

The drug's release comes after weeks of harrowing shortages of oxygen which has been increasingly required by patients during a deadly second wave of the pandemic.

Scores of deaths have been reported in cities across the country including Delhi, Bangalore and the Goa capital Panaji as oxygen supplies ran out at hospitals and home-care patients paid double and triple the price for concentrators and cylinders.

While the oxygen shortage continues in some regions, the situation has improved, with supplies almost doubling since the beginning of May, with Indian manufacturers increasing production, some logistical issues being resolved and international aid pouring in in the form of oxygen concentrators, cylinders and plants.

India has an official caseload of about 25 million infections, second only to the United States, and has suffered 274,390 deaths.

Experts maintain that both numbers are likely to be much higher in actuality.

Australian Associated Press