H7N9在禽流感中獨特在於它能夠同時攻擊人體，較早前的H5N1能夠深入肺部導致肺炎，但是尚且不能人傳人。H7N9攻擊肺部和上呼吸道，而且像普通感冒一樣可以透過咳嗽和噴嚏散播的病毒傳染。

－Malik Peiris教授，《細菌戰》，南華早報

“H7N9 is unique amongst bird flus in that it mounts a twin attack on the human body. The earlier strain, H5N1, penetrates deep into the lungs, where it causes pneumonia, but from there it is unable to transmit to other people. H7N9 attacks both the lungs and the upper airways. Like the common cold, it could potentially be passed from person to person when they cough and sneeze, releasing hordes of viruses into the air.”

– Prof. Malik Peiris, “Germ Warfare” article, SCMP Post Magazine.