Safety and Immunogenicity of a Booster Vaccination by CoronaVac or BNT162b2 in Previously Two-Dose Inactivated Virus Vaccinated Individuals with Negative Neutralizing Antibody oleh Kristi Tsz-Wan Lai, Emilie Yuen-Ting Lai Wan Loong, Terry Ling-Hiu Fung, Luke Wing-Pan Luk, Chor-Chiu Lau, Jonpaul Sze-Tsing Zee, Edmond Shiu-Kwan Ma, Bone Siu-Fai Tang