Children who had whooping cough during childhood, had a 1.5-2 times lower risk of developing some types of leukemia.
Measles is associated with a 47% reduced risk of chronic lymphocytic leukemia. The risk of lymphocytic leukemia is inversely associated with amount of childhood diseases (mumps, chickenpox, whooping cough, etc.). One or two childhood diseases reduced the risk by 16%, three or more diseases - by 53%.
Colds, fever and childhood infectious diseases are inversely associated with risk of leukemia.
A few similar papers:
Исследование 568 тысяч детей в Тайване. У детей, зараженных энтеровирусами, риск заболеть лейкемией был на 56% ниже.