What do you think of idea of using pandemic as a jumping off point? --idea that you really are capable of significant self-sacrifice for the greater good, and the kind of life changes that many EAs do are small compared sacrifice you have already made during pandemic.
--idea of thinking through with other person why it is obviously good for a government to buy vaccines for its population, given all the other things they could do with the money. I assume most people will use reasoning of helping the most people for low cost.
I have done around 20 practice interviews for mathematical subjects for Oxbridge. If in the off chance you need somebody to help do this, feel free to reach out. (If yes, let me know and I will share my contact details with you via linkedin)
Regardless, good luck with this! Very useful for teenagers to get this advice which is otherwise not available.