A case of interstitial lung disease following Oxford-AstraZeneca COVID-19 vaccination.

Ms TI presented with exertional dyspnoea and a dry, unproductive cough that commenced 1 week after receiving her second COVID‐19 vaccine in August 2021, both Oxford‐AstraZeneca vaxzevria COVID‐19. She did not experience notable adverse effects after her initial vaccine. She is an ex‐smoker, having stopped 20 years prior after 12 pack‐years of smoking. Her medical history includes a cholecystectomy and gastric reflux treated with pantoprazole. Notably, she had no history of interstitial lung disease or COVID‐19 infection. She lived rurally and worked in administration with no exposure to pigeons, dust or occupational inhalants.

Clinical examination was unremarkable, without the presence of wheeze or low oxygen saturations. Initial pulmonary function tests (PFT) demonstrated an obstructive pattern with FEV1 1.73 L (67% predicted), FVC 3.18 L (97.8% predicted), FEV1/FVC 54.53 and Diffusing capacity of the Lungs for Carbon Monoxide (DLCO) 20.5 (101.9% predicted). Bronchial alveolar lavage returned no evidence of infection and a predominant lymphocytosis (59% lymphocytes). A high‐resolution computed tomography (HRCT) scan demonstrated ‘a diffuse distribution of micronodules, all measuring less than 3 mm, … marked mosaic attenuation with ground‐glass and intervening areas of hyperlucency’ (Fig. 1). A comprehensive connective tissue disease serology screen returned negative. This case was discussed at a multi‐disciplinary interstitial lung disease meeting. Several differentials were considered but a diagnosis of drug‐induced interstitial lung disease (DIILD) was decided on, with a high degree of confidence.

Figure 1

High‐resolution computed tomography image of the patient's lungs at presentation demonstrating marked mosaic attenuation with ground‐glass and intervening areas of hyperlucency.

After diagnosis of DIILD, Ms TI was commenced on methylprednisolone, followed by 12 weeks of oral prednisolone with rapid improvement. Repeat PFT after 12 weeks demonstrated significant improvement with FEV1 2.34 L (91% predicted), FVC 3.35 L (105% predicted), FEV1/FVC 70 and DLCO 21.1 (105% predicted). Repeat HRCT at the 12‐week point demonstrated ‘complete resolution of previously seen pulmonary changes’ and by that time the patient was asymptomatic. Discussion regarding future vaccination is ongoing.

DIILD is a rare disease with varied presentation and no agreed‐on diagnostic criteria. As such, it remains a diagnosis of exclusion, with potential differentials including infection, haemorrhage, oedema or exacerbation of underlying lung disease. Dyspnoea and respiratory symptoms are common. The key diagnostic feature is a close temporal relationship to a causative drug, of which there are over 1000 known. HRCT commonly demonstrates multi‐lobar ground‐glass opacities. A hypersensitivity pneumonitis‐like pattern is occasionally found. PFT results are varied, with many cases having unremarkable results. A decreased DLCO is the most common and sensitive PFT abnormality. Steroids are the mainstay of treatment, and if the offending medication is ceased, the prognosis is generally favourable, as in the present case.

The COVID‐19 pandemic has led to rapid development of multiple COVID‐19 vaccines with generally favourable risk profiles. DIILD has been previously reported in seven cases post COVID‐19 vaccination, although all have been in individuals vaccinated with the Pfizer BNT162b2 vaccine, a mRNA vaccine. , , , DIILD has also been diagnosed after influenza vaccination in at least 10 cases. , There are no published cases of DIILD following the Oxford‐AstraZenca vaccination. Although the Oxford‐AstraZeneca COVID‐19 vaccine remains a safe and effective method of preventing COVID‐19 infection, clinicians should be aware of DIILD as a potential complication.