Association of vaccination status and immunosuppression with mortality of SARS-CoV-2 infection in patients with fibrotic interstitial lung disease.

Background: There are limited data exploring the outcome following SARS-CoV-2 infection in fibrotic interstitial lung disease (fILD). Our goal was to determine the association of vaccination for SARS-CoV-2 with both SARS-CoV-2 infection and subsequent 90-day mortality in fILD. Our second objective was to determine the association of immunosuppressive use with both SARS-CoV-2 infection and subsequent 90-day mortality in fILD.

Methods: Patients with fILD enrolled in the Canadian Registry for Pulmonary Fibrosis with comprehensive access to data on SARS-CoV-2 vaccination and PCR-confirmed infection were included. Associations of vaccination status and current immunosuppressant use with SARS-CoV-2 infection and subsequent 90-day mortality were tested using Fisher's exact test and subsequently multivariable logistic regression adjusting for age, sex, pre-identified comorbidities, forced vital capacity and diffusing capacity of the lung for carbon monoxide.

Results: Of 1452 total patients with fILD, 138 tested positive for SARS-CoV-2. On adjusted analysis, vaccination for SARS-CoV-2 was associated with a 60% reduction in the odds of infection (OR 0.40, 95% CI 0.24 to 0.67 p<0.001) and a 97% reduction in the odds of 90-day mortality following infection (OR 0.03, 95% CI 0.0007 to 0.26, p=0.01). SARS-CoV-2 was diagnosed in 13% of patients on an immunosuppressant and 9% of those not (OR 1.4, 95% CI 1.0 to 2.1, p=0.04). Immunosuppressant use was not associated with 90-day mortality after SARS-CoV-2 infection on adjusted analysis.

Conclusion: In patients with fILD, vaccination against SARS-CoV-2 was associated with decreased frequency of SARS-CoV-2 infection and subsequent 90-day mortality, while current use of immunosuppressive medication was associated with risk of infection but only a trend for subsequent 90-day mortality.