China made several 'traditional' vaccines instead of using mRNA technology like Sinovac. They have significantly lower effectivity numbers from what I've seen (~60% vs. ~90%). On the plus side, I think they also have fewer side effects.

That said, it's worth clarifying that their lesser effectivity comes from technological differences, not merely from being Chinese in origin.

I think it's more helpful to clarify that point than to discuss motives because it's true that some of the vaccines that happen to be Chinese in origin are provably less effective according to published studies, it's just not true that their Chinese origin is in any way causing this difference.