Effectiveness of heterologous mRNA vaccine boosters during an Omicron wave of COVID-19: a cross-sectional study in Macao (China)

Jinghua Zhang, Boyuan Wang, Eric Lau, Zhiqi Zeng, Wei He, C. L. Philip Chen, Chiwai Chang, Zifeng Yang, Ka-Lok Tong, Nanshan Zhong, Chitin Hon