WHO confident about Sinopharm vaccine efficacy, not happy with data Top Story May 6, 2021 GENEVA: WHO experts have voiced “very low confidence” in data provided by Chinese state-owned drugmaker Sinopharm on its COVID-19 vaccine regarding the risk of serious side-effects in some patients, but overall confidence in its ability to prevent the disease, a document seen by a British news agency shows. A World Health Organization spokesman said that the document on Sinopharm vaccine BBIBP-CorV was “one of many resources” on which recommendations are made, tentatively scheduled to be issued later this week. In Beijing, Sinopharm, was not immediately reachable for comment outside working hours.