Some 75 percent of people aged 65 and over in Japan have received at least one dose of a COVID-19 vaccine, with most of them set to be fully vaccinated by the end of July, a government tally showed Saturday.

The drive, launched in April to vaccinate the elderly population of around 35.48 million, has gained momentum under Prime Minister Yoshihide Suga's target to finish inoculating the demographic by the end of July.

Challenges remain, however, in expanding vaccinations to those under 65 as the government is unable to distribute doses quickly enough.

Due to a supply shortfall, some municipalities are being forced to restrict accepting reservations, while new applications by companies and universities for workplace vaccinations have also been suspended.

As of Friday, 26.65 million, or 75.1 percent of the elderly, had received one shot, according to the government tally.

As the figure does not include all vaccinated people aged 65 or older, such as health care workers, a government official said the actual number of elderly who have received their first shot is higher.

Since the second shot of U.S. pharmaceutical company Pfizer Inc.'s two-dose vaccine, which is widely used in inoculating the elderly, is administered three weeks after the first, most of the 26.65 million are expected to be fully vaccinated by the end of the month.

Takaji Wakita, head of the National Institute of Infectious Diseases, said completing the vaccination of 70 to 80 percent of the elderly shows that the inoculation drive is going steadily.

"Elderly are at the highest risk (for the coronavirus). I hope further efforts will be made to raise the vaccination rate among the elderly to around 90 percent through means such as visiting the homes of those who have difficulties going to vaccination sites," Wakita said.

Suga has said he aims to promote the vaccination of those under 65 and finish inoculating all eligible people in Japan who wish to receive shots by November as the country grapples with a resurgence of infections.

Suga's top COVID-19 adviser, Shigeru Omi, cautioned against the recent rise in patients with severe symptoms in the 40s and 50s due to the spread of the highly contagious Delta variant of the coronavirus, first detected in India.

Omi said vaccinating those in their 40s and 50s early is the key to containing the pandemic in the future.

The Tokyo metropolitan government reported 950 new coronavirus cases on Saturday, exceeding the number logged a week earlier for the 21st straight day.

The capital will be placed under a fresh COVID-19 state of emergency from Monday until Aug. 22, covering the duration of the Tokyo Olympics.