Chan wrote in her blog today that only around 500,000 are vaccinated in the city, marking the vaccination rate less than 20 percent. There is a long way to go before the goal of herd immunity can be achieved, scientifically speaking, she said.

Herd immunity is believed to require a vaccination rate of around 70 percent.

Chan also pointed out that government will include vaccination as a condition when modifying healthcare measures, in order to encourage people to have their shots. Social distancing measures will also be less stringent if the vaccination rate goes up, Chan said.

Besides, Chan noted that HK$170 million was granted by the Health and Medical Research Fund. The fund will support 49 research projects on Covid-19, including 4 vaccine projects conducted by two local universities.

The nasal spray vaccine developed by the Department of Microbiology of the University of Hong Kong, has commenced phase 1 clinical trial, Chan said. Over 100 healthy adults volunteered in the trial in late March.

Chan went on that the government will subsidize more research projects on Covid-19 vaccines in the upcoming years, including examining the effectiveness of the vaccines and how long the antibodies can stay effective.