(Photo: NBC News/VNA)

According to the officials, vaccine candidates will undergo further testing to whittle down the number to six or eight. That batch of candidates will enter rounds of clinical trials to select three or four vaccines that could be in widespread use by early 2021.

Meanwhile, the UK will run trials for a new coronavirus tracing program next week on the Isle of Wight, just off the south coast of England, cabinet minister Michael Gove said on Sunday, as the British government looks for a way to minimize the risk of a second wave of infection.

Israeli researchers have developed a method to predict coronavirus outbreaks by testing sewage systems, Ben-Gurion University said Sunday. The researchers say the presence of the virus in wastewater indicates infection in the area, and the virus count increases as more people are infected.

The research team has found the COVID-19 virus in several locations in Israel, including the sewage system of BneiBrak city, a hot spot of the epidemic.