China could reach herd immunity against Covid-19 by end of year, Zhong Nanshan says


Respiratory disease expert Zhong Nanshan said Covid-19 vaccines were less effective six months after the first dose, but herd immunity was still achievable with booster shots. Photo: Handout


Respiratory disease expert Zhong Nanshan said Covid-19 vaccines were less effective six months after the first dose, but herd immunity was still achievable with booster shots. Photo: Handout