“…Two very recent preprints reporting N-glycosylation on spike protein of SARS-CoV-2 showed different glycosylation profiles, and both reports were different from our results although all three studies utilized recombinant S protein from an HEK 293-based expression system (Watanabe, Y., Allen, J.D., et al , Zhang, Y., Zhao, W., et al 2020. This indicates the caution to be exercised in determining the glycosylation on viral antigens generated from various sources as the changes in glycosylation pattern can influence the efficacy of potential vaccine candidates (Chang, D. and Zaia, J. 2019).…”