COVID-19 Vaccination and Breakthrough Infections in Patients with Cancer
Among the 54 fully vaccinated patients who developed COVID-19 (data from ClinicalTrials.gov study NCT04354701), 35 (65%) were hospitalized, 10 (19%) were admitted to ICU or required MV, and 7 (13%) died within 30 days. Comparable rates were observed in the unvaccinated group.
The primary endpoint was 30-day all-cause mortality among fully vaccinated patients compared to the unvaccinated population after Inverse Probability of Treatment Weighting (IPTW) to adjust for baseline clinical variables. SFollowing IPTW, there was no statistical difference in 30-day mortality between the fully vaccinated patients compared to the unvaccinated cohort Adjusted Odds Ratio (AOR) 1·08, 95% CI: 0·41-2·82. Increased 30-day mortality was associated with lymphopenia (AOR 1·68, 95% CI: 1·11-2·55), the presence of comorbid conditions (mCCI of 1 vs 0: AOR 1·66, 95% CI: 1·07-2·59 and mCCI ≥2 vs 0: AOR 2·10, 95% CI: 1·36-3·24), worse performance status (ECOG PS 1 vs 0: AOR 2·26, 95% CI: 1·25-4·06 or ECOG PS ≥2 vs 0: AOR 4·34, 95% CI: 2·35-8·02) and baseline cancer status (active and progressing versus not active and progressing, AOR 6·07, 95% CI: 4·00-9·19).
Based on the accumulation of knowledge to date, it appears that patients with hematologic malignancy are less likely to mount an effective immune response.