SARS-CoV-2 vaccines show protective efficacy, which is most likely mediated by neutralizing antibodies recognizing the viral entry protein, spike. Because new SARS-CoV-2 variants are emerging rapidly, it is critical to understand whether antibody responses induced by infection with the original SARS-CoV-2 virus or current vaccines remain effective. Some variants with amino acid change at receptor binding domain became resistant to some neutralizing antibodies. Moreover, the majority of glycosylation deletions reduced infectivity, revealing the importance of glycosylation for viral infectivity. This work highlights that changes in SARS-CoV-2 spike can alter neutralization sensitivity and underlines the need for effective real-time monitoring of emerging mutations and their effect on vaccine efficacy.