I think you are getting confused about the vaccine from different country .I think every vaccine is effective to grow your immunity system high .I don't actually know how the percentage of effectiveness of the vaccine comes from .All the vaccine which are recognized by the WHO are effective on the human body .If you got Sinovac your country just take it .It is impossible to give vaccine to the mass community in short time gradually it will cover .
Obviously getting vaccinated with whatever vaccine available is far better than remaining unvaccinated. But now the vaccine companies have scaled up their production (especially Pfizer and AstraZeneca) and unlike the situation a few months back (when Sinovac and Sinopharm were the only vaccines that were available in large quantities), now the users can make a choice. Sinovac/Sinopharm would be at the bottom of my preference, because different studies have shown that it's efficacy is very low. One example here:
https://www.bmj.com/content/373/bmj.n969A study of the Sinovac rollout by the University of Chile reported that the vaccine was 56.5% effective two weeks after second doses were administered in the country. However, they also reported that one dose was just 3% effective (rising to 27.7% within two weeks of the second dose, and 56.5% two weeks later).