Analyzing real-world data to understand COVID-19 vaccination effects on hospitalization rates in patients with solid malignancies

Figures & data

Figure 1. The patient cohort selection process was standardized across both groups. The isolated patient groups were required to have a solid malignancy as their only documented pathology. Any duplicate cases, if identified, were excluded from the study. These cohorts were then further stratified based on criteria such as sex, age and viral variant.

Table 1. Confirmed COVID-19 cases in cancer patients by vaccination status and hospitalizations indexed between March 2020 and June 2022.

Criteria	Total (n = 4013)	Unvaccinated (n = 3305)	Vaccinated (n = 708)	OR (95% CI)
Hospitalizations (cancer w/ comorbidities)	n = 1911	1630/3305 (49.3%)	281/708 (39.7%)	0.6762 [0.5732–0.7978]; p < 0.0001
Hospitalizations (cancer w/o comorbidities)	n = 741	631/1474 (42.8%)	110/323 (34.1%)	0.6899 [0.5361–0.8879]; p = 0.0039
Age ≤63 – Hosp.	n = 290	241/671 (35.9%)	49/154 (31.8%)	0.8326 [0.5728–1.2103]; p = 0.3371
Age >63 – Hosp.	n = 451	390/803 (48.6%)	61/169 (36.1%)	0.5981 [0.4244–0.8429]; p = 0.0033
Male – Hosp.	n = 360	305/647 (47.1%)	55/149 (36.9%)	0.6492 [0.4501–0.9363]; p = 0.0208
Female – Hosp.	n = 381	326/827 (39.4%)	55/174 (31.6%)	0.7103 [0.5012–1.0066]; p = 0.0545
mRNA based vaccine – Any admission	n = 701	631/1474 (41.8%)	70/230 (30.4%)	0.5845 [0.4333–0.7884]; p = 0.0004
Viral vector based vaccine – Any admission	n = 658	631/1474 (41.8%)	27/67 (32.8%)	0.9018 [0.5475–1.4853]; p = 0.6847
Hosp. Alpha (B.1.1.7)	n = 142	107/284 (67.7%)	35/109 (32.1%)	0.7824 [0.4898–1.2497]; p = 0.3044
Hosp. Beta (B.1.351)	n = 217	191/452 (42.3%)	26/73 (35.6%)	0.7559 [0.4521–1.2640]; p = 0.2861
Hosp. Delta (B.1.617.1)	n = 261	233/482 (48.3%)	28/68 (41.2%)	0.7481 [0.4470–1.2519]; p = 0.2692
Hosp. Omicron (B1.1.529)	n = 121	100/256 (39.0%)	21/163 (12.9%)	0.2307 [0.13687–0.3890]; p < 0.0001
ICU admission	n = 211	195/1474 (13.2%)	16/323 (4.9%)	0.3418 [0.2023–0.5777]; p = 0.0001
Pooled data	–	–	–	0.7103 [0.4898–0.9969]; p = 0.0575

Figure 2. A Forest Plot of the unadjusted univariate analyses in the confirmed COVID-19 cases in cancer patients.

Data availability statement

The data supporting the findings of this study are available upon formal request from the Ministry of Health of the Republic of Bulgaria. Access to these data is subject to restrictions and was obtained with permission for this specific study. For data access, please visit https://coronavirus.bg/ in compliance with the Ministry of Health’s policies and guidelines.