RESUMO
ObjectiveWe conducted a longitudinal study to estimate immunity produced in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among university students over seven months. MethodsAll participants were attending a public university and resided in Pitt County, North Carolina. University students enrolled weekly for 10 weeks between August 26, 2020 and October 28, 2020, resulting in 136 young adults completing at least one study visit by November 17, 2020. Enrolled students completed an online survey and nasal swab collection at two week intervals and monthly blood collection between August 26, 2020 and March 31, 2021. ResultsAmongst 695 serum samples tested during follow-up, the prevalence of a positive result for anti-nucleocapsid antibodies (N-IgG) was 9.78%. In 22 students with more than one positive N-IgG serum sample, 68.1% of group had decline of N-IgG below positive threshold over 140 days. Anti-spike antibodies were detected in all 11 vaccinated students who were vaccinated during March 2021. ConclusionsIn healthy young adults, N-IgG wanes below detectable threshold within five months. S-IgG remained consistently elevated months after infection, and significantly increased after vaccination.
