The proportion of the world's infants vaccinated against diphtheria, whooping cough, and tetanus has climbed from less than half to 82 percent between 1985 and 2008.

It is very important that babies get immunised against whooping cough.

The earliest Bloodlines occasionally still depicted particular individuals - as with Zhang's portraits of his own mother and father or his paintings based on his "100th day" baby portrait.