Humoral immunoresponse elicited against an adenoviral-based SARS-CoV-2 coronavirus vaccine in elderly patients

TOMAS-GRAU, RODRIGO HERNÁN; MALDONADO-GALDEANO, CAROLINA; LÓPEZ, MÓNICA AGUILAR; PINGITORE, ESTEBAN VERA; AZNAR, PATRICIA; ALCORTA, MARÍA ELENA; DEL MAR VÉLEZ, EVA MARÍA; STAGNETTO, AGUSTÍN; SOLIZ-SANTANDER, SILVANA ESTEFANÍA; ÁVILA, CÉSAR LUÍS; SOCIAS, SERGIO BENJAMÍN; COSTAS, DARDO; CHAHLA, ROSSANA ELENA; PERDIGÓN, GABRIELA; CHEHÍN, ROSANA NIEVES; PLOPER, DIEGO; CAZORLA, SILVIA INÉS

Aging

Impact journals

Año: 2022 vol. 14

1945-4589

The early sequencing of the SARS-CoV-2 viral genome allowed for a speedy development of effective vaccinesagainst the virus. Nevertheless, age-related immunosenescence, the inability to mount strong immune responses,still represents a major obstacle. Here, in a group of 149 elderly volunteers (70–96 years old), evolution of thehumoral immune response over time to Gam-COVID-Vac (Sputnik V), a vaccine based on heterologousrecombinant adenovirus-26 (Ad26) and adenovirus-5 (Ad5) carrying the Spike genome, was analyzed by an antiRBD ELISA. At 28 days post vaccination (dpv), a seroconversion rate of 91% was achieved, showing the importanceof administering at least two doses of Gam-COVID-Vac to elicit a robust immune response, especially in elderlyindividuals without previous SARS-CoV-2 infection. Interestingly, IgG specific antibodies that reached their highesttiters around 28 dpv (median = 740), persisted without significant decrease after 60 dpv (median = 650). After90 dpv, IgG titers began to drop, and at 180 dpv only 44.7% of the elderly individuals remained with detectableanti-RBD IgG antibodies. No significant differences were observed in specific humoral immune responses betweengenders at early times point. However, at 60 dpv anti-RBD titers were more persistent in elderly females, and onlydropped at 90 dpv (p < 0.0001). As expected, the highest antibodies titers were elicited in the youngest subgroup(70–74 years). Our results show that Gam-COVID-Vac was able to deal with the ageing of the immune system,eliciting a robust immune response in an elderly cohort, which lasted approximately 90 dpv at high levels, andprotected against COVID-19.