translation.da: Spædbørn på under seks måneder hoster ikke, men bliver stakåndede og får svært nedsat iltforsyning (asfyksi) og vil ubehandlet som regel dø af sygdommen.
translation.en: Babies less than six months old do not cough, but they manifest shortness of breath and severely deficient supply of oxygen to the body (asphyxia) and are the most likely to die of the disease unless they receive suitable treatment.