To avoid this scam you need to have a good knowledge how scam works, they play with your emotion so having a calm and collected demeanor surely helps a lot when dealing with this. Help your old folks to know that there are scammers, the reason they fall for the bait is they are not informed. Instead of donating in charities in Internet, you should instead donate in your local charity, they are more legitimate.
Not all have that but that's why we need to share what we notice so that people will avoid those scam things related to covid, and it's so easy to tell which is scam and those who offer to good to be true are scams and any related with covid especially promising with a cure or insurance is totally a big red flag.