As coronavirus vaccines continue to roll out around the world, there's a growing focus on the differences among versions. The Pfizer and Moderna vaccines have a high rate of effectiveness. So does the Astra Zeneca version. But there's a bit more uncertainty with some vaccines coming from China.
This has been a confusing week for COVID-19 vaccines developed in China.
CoronaVac is a treatment made by the Chinese company Sinovac. This week researchers in Brazil released a study finding an effectiveness rate of 50.4% — just barely above the level generally cleared by health officials, including the World Health Organization.
It’s a drop from the 78% level previously reported, and far below the 90-something percent readings hit by the three Western-produced vaccines currently in play: from Pfizer, Moderna and Astra Zeneca.
Hong Kong is one of the locations that’s put a hold on Sinovac injections until health officials can review further data.
Indonesia went ahead with its roll-out of Sinovac vaccines this week.
Singapore, Malaysia and the Philippines are among other countries in the Asia Pacific with SinoVac products on order.
Another Chinese company developing vaccines is SinoPharm — with at least two versions in the works.
At the end of December, SinoPharm announced phase three trials of one version showed an effective rate of 79% — while a later phase three trial in the United Arab Emirates showed an 86% effectiveness rate, according to the UAE government.
Peer reviewed research is underway with several Chinese vaccines, but results so far have been incomplete.