ISLAMABAD: A COVID-19 vaccine developed by CanSino Biologics Inc (CanSinoBIO) showed 65.7% efficacy in preventing symptomatic cases, and 90.98% efficacy in stopping severe disease in interim multi-country trial results, Pakistan's Health Minister Faisal Sultan said on Monday.

The vaccine, jointly developed by a research institute affiliated with the Chinese military, follows two competing shots from Chinese companies Sinovac and state-backed Sinopharm that showed efficacy of between 50% and 91%.

Although vaccines from Chinese developers have shown lower protection rates than some Western products, and no detailed study results are publicly available yet, they have already been approved in several developing countries battling a surge in coronavirus infections.

The efficacy of CanSinoBIO's vaccine, the one-dose Ad5-nCoV, is based on analysis of 30,000 participants and 101 cases of COVID-19, the minister said on Twitter, quoting data from an independent data monitoring committee.

In the Pakistani subset, efficacy of the CanSinoBIO vaccine at preventing symptomatic cases was 74.8% and 100% at preventing severe disease, Sultan added.

CanSinoBIO was not immediately available for comment.