New research suggests that mRNA COVID-19 vaccines can elevate PD-L1 expression levels in patients with advanced non-small cell lung cancer (NSCLC).

This increase in PD-L1 expression could be sufficient to restore sensitivity to immune checkpoint inhibition in patients with resistant disease, according to Adam Grippin, MD, PhD, of the University of Texas MD Anderson Cancer Center in Houston.

Dr Grippin presented this research at the 2023 World Conference on Lung Cancer.

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Because preclinical research has shown that mRNA vaccines stimulate tumor PD-L1 expression, Dr Grippin and colleagues decided to assess whether mRNA COVID-19 vaccines would increase PD-L1 expression in biopsy samples from patients with advanced NSCLC.

The researchers evaluated patients with stage III-IV NSCLC who had undergone biopsies between January 2017 and August 2022. The cohort included 2216 NSCLC patients with a total of 2406 samples.

The patients were divided into 4 groups based on the interval between vaccine administration and the biopsy date:

  • 0-69 days: 116 patient samples
  • 70-99 days: 52 samples
  • 100-746 days: 254 samples
  • No pre-biopsy vaccine: 1984 samples.

There were no significant differences in histology, clinical stage, sex, or race/ethnicity between these groups. However, unvaccinated patients were slightly younger than the other patients.

Dr Grippin and colleagues found that the interval between COVID-19 vaccination and biopsy was significantly associated with PD-L1 tumor proportion score (TPS).

The average PD-L1 TPS was substantially higher in patients who had a biopsy 70-99 days after COVID-19 vaccination (40%) than in patients who had a biopsy 0-69 days from vaccination (25%), those who had a biopsy 100 or more days from vaccination (21%), and those who were not vaccinated (24%).

Patients who had a biopsy 70-99 days after COVID-19 vaccination also had a significantly higher proportion of samples with a PD-L1 TPS of 50% or higher. The proportion of samples with a TPS of 50% or higher was 42% in the 70-99 days group, 27% in the 0-69 days group, 23% in the 100-746 days group, and 27% in the vaccine-free group.  

“The tumor proportion score of PD-L1 more frequently exceeded clinically relevant thresholds in patients who received COVID mRNA vaccines, in a time-dependent manner,” Dr Grippin said. “Our future work will consider the mechanism behind this time-dependent increase in PD-L1 expression and consider the relationship of the timing of COVID mRNA vaccines and clinical responses to immune checkpoint blockade.”

Disclosures: No disclosures were provided.


Grippin A, De B, Fink K, et al. Timing of pre-biopsy COVID-mRNA vaccination and PD-L1 expression in advanced non-small cell lung cancer. Presented at WCLC 2023. September 9-12, 2023. Abstract MA15.04.