BBC News By Tessa Wong image captionIndonesia has been mainly using Sinovac's vaccine in its Covid immunisation programme Across Asia, Chinese vaccines have played a crucial role in immunising people against Covid-19, with millions receiving either a Sinovac or Sinopharm jab. But in recent weeks, concerns have grown about their efficacy. Now, some Asian countries which made Chinese vaccines a key plank in their immunisation programmes have announced they will use other jabs. The move has raised questions, not only about whether China's vaccines can be trusted, but also about its attempts at vaccine diplomacy in Asia. What's happening in Thailand and Indonesia?