I believe that you should create your passion rather than find it. As 80,000 Hours claimed and here also. Plus, I want to say that I'm just like you! Even I'm starting my A-Levels journey this year and am not sure what field I want to pursue.

I hope you find your dream and passion career where you can have the highest impact!

Thanks for this question! I believe that we need to build organizations and nonprofits that aim for this goal. We've seen a lot of very well-known nonprofits that fund the amazing discoveries in other countries (mainly in the USA and UK) but near to none fund the African researchers and/or universities. 

Also, we need African politicians and economists who aim to change the governance in these countries to favor research and fund them. Not only financially but also by encouraging young students and change-makers to start their organizations and conduct researches to achieve this goal.