JERUSALEM (BLOOMBERG) - Pfizer and BioNTech's coronavirus vaccine blocked 94 per cent of asymptomatic infections in an Israeli study that further builds the case for the shot's overwhelming effectiveness against the virus a year after the pandemic began.

The vaccine stopped 97 per cent of symptomatic cases, hospitalisations and deaths, the companies and the Israeli Ministry of Health said on Thursday (March 11).

Crucially, the results were measured two weeks after the second dose, suggesting that high efficacy seen after the first dose of the shot may be even better once vaccination is complete.

"This clearly demonstrates the power of the Covid-19 vaccine to fight this virus," Professor Yeheskel Levy, director of the health ministry, said in a statement.

"We aim to achieve even higher uptake in people of all ages, which gives us hope of regaining normal economic and social function in the not-so-distant future."

Israel leads the world in pandemic vaccination after beginning its inoculation campaign in December. More than half the population has had at least one dose.

The country also agreed to collect and share real-world data on how well the vaccine is working, turning its roll-out into a case study for the rest of the world.

The findings on preventing asymptomatic infections are "particularly meaningful as we look to disrupt the spread of the virus around the globe," Dr Luis Jodar, senior vice-president and chief medical officer of Pfizer's vaccines unit, said in a statement.

Israel's use of the Pfizer-BioNTech vaccine coincided with broad spread of the more infectious virus variant first identified in Britain, meaning that the efficacy observed in the country indicates the vaccine also works well against that mutant strain.