Effect of an Exercise Bout Prior to the Booster Dose of an Inactivated SARS-CoV-2 Vaccine on Immunogenicity in Immunocompromised Patients

Abstract

This study aimed to investigate whether a single bout of exercise prior to the homologous booster dose of a SARS-CoV-2 inactivated vaccine (Sinovac-CoronaVac) could enhance immunogenicity in patients with dysfunctional immune system. This was a randomized controlled trial (1:1) within a single-arm, phase 4 vaccination trial, conducted in São Paulo, Brazil. Patients with spondyloarthritis assigned to the intervention group performed an exercise bout comprising three unilateral strength exercises involving eccentric and concentric contractions. After exercising, patients remained at rest for 1 h prior to vaccination, which was applied to the exercised arm. The control group remained at rest before vaccination. Immunogenicity was assessed before (Pre) and one month after (Post) the booster dose using seropositivity rates of total anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG (GMT), frequency of NAb positivity, and NAb activity. Before the booster dose, 16 patients from the exercise group and 16 patients from the control group exhibited seropositivity for IgG (59% vs. 57.1%), one month after the booster dose, seropositivity occurred in 96% vs. 100% of the cases (p = 0.84, group by time interaction). Only 10 patients from the exercise group and 12 patients from the control group showed positive NAb serology at Pre (37% vs. 42.8%). One month following the booster, NAb positivity was 96% vs. 93% (p = 0.41, group-by-time interaction). GMT was comparable between groups at Pre (p > 0.05). At Post, GMT increased similarly in both groups (exercise: 56.9%; control: 57.9%), with no group-by-time interaction (p = 0.82; estimated mean difference between groups at Post [EMD]: -40.4 UA/mL, 95%CI: -327, 246 UA/mL). Likewise, NAb activity was similar between groups at Pre and increased similarly in both of them as a result of the booster (47.5% vs. 39.9%), with no group-by-time interaction (p = 0.99; EMD: -6.19%, 95%CI: -17; 4.6%). In conclusion, a single bout of exercise did not enhance immunogenicity to a homologous booster dose of an inactivated SARS-CoV-2 vaccine among patients with spondyloarthritis. Studies assessing exercise as an adjuvant to first or second doses remain necessary.