Immune responses following the first dose of the Sputnik V (Gam-COVID-Vac).
Jeewandara C., Fernando S., Pushpakumara PD., Ramu ST., Kamaladasa A., Gunasekara B., Aberathna IS., Kuruppu H., Ranasinghe T., Dayarathne S., Dissanayake O., Gamalath N., Ekanayake D., Jayamali J., Wijesinghe A., Dissanayake M., Somathilake G., Harvie M., Danasekara S., Jayathilaka D., Wijayatilake HDK., Weerasooriya N., Kekulandara C., Schimanski L., Rijal P., Tan TK., Dong T., Townsend A., Ogg GS., Malavige GN.
As the first dose of Gam-COVID-Vac, is currently used as a single dose vaccine in some countries, we investigated the immunogenicity of this at 4 weeks (327 naïve individuals). 88.7% seroconverted, with significantly lower seroconversion rates in those over 60 years (p = 0.004) and significantly lower than previously seen with AZD1222 (p = 0.018). 82.6% developed ACE2 receptor blocking antibodies, although levels were significantly lower than following natural infection (p = 0.0009) and a single dose of AZD1222 (p