Apparently there was even a small protective effect from children in the household, though this went away after schools reopened. One of the hypotheses in this

Apparently there was even a small protective effect from children in the household, though this went away after schools reopened. One of the hypotheses in this paper is cross-immunity with other circulating coronaviruses: https://adc.bmj.com/content/archdischild/early/2021/03/17/archdischild-2021-321604.full.pdf https://adc.bmj.com/content/archdischild/early/2021/03/17/ar... Based on this, I will continue my practice of licking subway handrails instead of religiously “sanitizing” everything like the person preparing to sit next to me just did.