ABSTRACT
Background: Patients with interstitial lung disease (ILD) are at high risk of severe COVID-19 infection. Method(s): We conducted an observational prospective cohort study to evaluate the rate of anti-spike (S-IgG) antibodies after two doses of the BNT162b2 vaccine in patients with ILD. The cohort included 40 patients with idiopathic pulmonary fibrosis (IPF) treated with anti-fibrotic therapy and 29 patients with non-IPF ILD treated with anti-inflammatory therapy. An age and sex matched control groups was created from a healthy control cohort of 107 patients. Result(s): All patients in the anti-fibrotic arm were seropositive (40/40), corresponding to the matched control group (P=1.0). The antifibrotic arm had a significantly lower median antibody titer in comparison to the matched control group (361.10 [ IQR, 207-811] AU/ml vs 820.75 [IQR, 459-1313] AU/ml;P<0.001). Only 48.3% (14/29) of patients in the anti-inflammatory arm were seropositive in comparison to 100% (29/29) in the healthy control group (P<0.001). The anti-inflammatory arm had a significantly lower median antibody titer in comparison to the healthy control group (39.6 [ IQR, 4.25-165] AU/ml vs 970.1 [IQR, 505-1926] AU/ml;P<0.001). Conclusion(s): IPF patients treated with antifibrotic therapy mount an adequate immune response after 2 doses of the BNT162b2 vaccine, maintain a 100% seropositivity rate, 4-6 months after vaccination. Among patients with non-IPF ILD, treated with anti-inflammatory therapy, 48% were seronegative 4-6 months after the second vaccine dose.