The Beijing-based biopharmaceutical company Sinovac is behind the CoronaVac, an inactivated vaccine.To get more news about sinopharm vaccine, you can visit shine news official website.
It works by using killed viral particles to expose the body's immune system to the virus without risking a serious disease response.
By comparison the Moderna and Pfizer vaccines being developed in the West are mRNA vaccines. This means part of the coronavirus' genetic code is injected into the body, triggering the body to begin making viral proteins, but not the whole virus, which is enough to train the immune system to attack.
"CoronaVac is a more traditional method [of vaccine] that is successfully used in many well known vaccines like rabies," Associate Prof Luo Dahai of the Nanyang Technological University told the BBC.
"mRNA vaccines are a new type of vaccine and there is [currently] no successful example [of them] being used in the population," Prof Luo adds.On paper, one of Sinovac's main advantages is that it can be stored in a standard refrigerator at 2-8 degrees Celsius, like the Oxford vaccine, which is made from a genetically engineered virus that causes the common cold in chimpanzees.
Moderna's vaccine needs to be stored at -20C and Pfizer's vaccine at -70C.
It means that both Sinovac and the Oxford-AstraZeneca vaccine are a lot more useful to developing countries which might not be able to store large amounts of vaccine at such low temperatures.Zhu Fengcai, one of the paper's authors, said those results - based on 144 participants in the phase one trial and 600 in the phase two trial - meant the vaccine was "suitable for emergency use".
CoronaVac has been undergoing phase three trials in various countries. Interim data from late-stage trials in Turkey and Indonesia showed that the vaccine was 91.25% and 65.3% effective respectively.
Researchers in Brazil initially said it was 78% effective in their clinical trials, but in January 2021 revised that figure to 50.4% after including more data in their calculations. Earlier in November, their trials were briefly halted after the reported death of a volunteer, but resumed after the death was found to have no links to the vaccine.
Sinovac has been approved for emergency use in high-risk groups in China since July.
In September, Mr Yin of Sinovac said tests were performed on more than 1,000 volunteers, of which "some only showed minor fatigue or discomfort… no more than 5%".Prof Luo had said ahead of the phase three results that it was difficult to make comments about the vaccine's efficacy at that point in time "given the limited information available".
"Based on the preliminary data... CoronaVac is likely an effective vaccine, but we do need to wait for the results of the phase three trials," he said.
"These trials are randomised, observer-blind, placebo-controlled... with thousands of participants. This is the only way to prove a vaccine is safe and effective to be used at the population level."