These results are also consistent with the Phase I data that showed immunity in the adults from ages 18 to 55. It is also now being trialled in South Africa.
China has been giving experimental Covid-19 vaccines to people including state employees, global students, and essential workers heading overseas since July. CNN has not seen the results of these trials yet.
On the other hand, Moderna Inc said its experimental vaccine was 94.5% effective in preventing COVID-19 based on interim data from a late-stage clinical trial, becoming the second USA company in a week to report results that far exceed expectations.
From the earlier phase data, researchers found that younger participants experienced side effects like pain at the vaccine's injection site, fever and muscle ache more often than older adults.
Besides the recipients of the Sinopharm jabs, authorities in Zhejiang said they had made a COVID-19 vaccine developed by the privately owned pharmaceutical company Sinovac Biotec available to high-risk groups in the east China province under the emergency use scheme.
The phase 2 trial saw 560 participants, 240 of whom were over 70, split into groups that received either one or two doses of the vaccine, or a placebo.
Oxford University will start an initial analysis of data from its late-stage trial after 53 infections among its volunteers, the study's chief investigator said on Thursday.
The symptoms were also similar to those seen in a flu vaccine, including tiredness and headache.
As of November 20, Ukraine reported 598,085 laboratory-confirmed COVID-19 cases, including 14,575 new cases recorded in the past 24 hours.
Sinopharm has two vaccine candidates.
Israel is in the final stages of talks with British pharmaceutical giant AstraZeneca to purchase "millions" of doses of its vaccine, which is now under trial, Prime Minister Benjamin Netanyahu announced Friday.
"What this could mean is that in the future when we're looking to boost people's responses, we might need to do it more often in older people than we do with younger people, but we're not thinking that we're going to need to boost people a few times a year as we do with the flu vaccine". He said, "We will need all of them to protect people around the globe". These antibodies that block the virus from entering cells can be measure in the lab, Ramasamy explained. "The next step will be to see if this translates into protection from the disease itself". Instead, it looked at safety indicators and the body's immuneresponse.
He said, "We have two challenges in front of us now". After the promising interim results of the Pfizer and Moderna Phase 3 trials, the results of the Oxford Vaccine Phase 2 trial have been published.
So far 1.2 million people have died of COVID-19, the disease caused by the virus.
"We will continue to work to ensure that we will have as many vaccines for as many citizens, from as many sources and as fast as possible", he said.