There are people who simply do not contract Covid-19, even if all their family and friends are infected around them. How can that be? Professor Ajit Lalvani from London knows the secret. What he and his team have now found gives hope. Because the knowledge could even ensure that we are all immune in the future, no matter how many variants are still to come. RTL reporter Thomas Meier met the researchers exclusively and found out why. You can see the result in the video. (kko)