ሆኖም በሽታውን መቋቋም ለማይችሉ ተጓዳኝ በሽታ ላለባቸውና ለአረጋውያን በማስተላለፍ ከፍተኛ ጉዳት ያደርሳሉ።
But in contracting an infection that does them no harm, they might pass it on to people who are in danger from it, namely the old and the already ill.