CRP and susceptibility to pneumonia measurement: CRP showed a significant increase in patients with post-COVID-19 pneumonia (9.57 ± 9.02 mg/L vs. 4.85 ± 2.80 mg/L, p = 0.046) as well as interleukin-6 (IL-6) levels that were substantially elevated in the pneumonia group (6.75 ± 6.59 pg/mL vs. 1.43 ± 1.77 pg/mL, p < 0.001).