Abstract Background Several clinical studies tested the efficacy of the different COVID-19 vaccinations while very few radiological researches targeted this issue before. Aim of the work To verify the additive role of lung CT-Volumetry in testing the efficacy of three widely distributed COVID-19 vaccinations; namely the "Sinopharm", "Oxford-AstraZeneca", and "Pfizer-BioNTech" vaccinations, with comparative analysis of variance (ANOVA). Results This study was retrospectively conducted on 341 COVID-19 patients during the period between June/2021 and March/2022. Based on the immunization status, they were divided into four groups; group (A) included 156/341 (46%) patients who did not receive any vaccination (control group), group (B) included 92/341 (27%) patients who received "Sinopharm" vaccine, group (C) included 55/341 (16%) patients who received "Oxford-AstraZeneca" vaccine, group (D) included 38/341 (11%) patients who received "Pfizer-BioNTech" vaccine. Every group was subdivided based on the medical history into three groups; group (1) patients without comorbidities, group (2) patients with comorbidities, and group (3) immunocompromised patients. Automated CT volumetry was calculated for the pathological lung parenchyma. Five CT-severity scores were provided (score 0 = 0%, score 1 = 1–25%, score 2 = 25–50%, score 3 = 51–75%, and score 4 = 76–100%). Analysis of variance (ANOVA) including Tukey HSD testing was utilized in comparison to the non-immunized patients. The "Phizer-Biontech" vaccine succeeded to eliminate severity in patients without and with comorbidity, and also decreased severity in immunocompromised patients (from 79 to 17%). The "Oxford-AstraZeneca" vaccine and to a lesser extent "Sinopharm" vaccine also decreased the clinical severity in patients with comorbidities and immunocompromised patients (from 15 to 9% & 10% as well as from 79 to 20% & 50% respectively). Significant variance was proved regarding the use of "Sinopharm", "Oxford-AstraZeneca", and "Phizer-Biontech" vaccines in patients without comorbidities (f-ratio averaged 4.0282, 10.8049, and 8.4404 respectively, also p-value averaged 0.04632, 0.001268, and 0.004294). Significant variance was proved regarding the use of "Oxford-AstraZeneca", and "Phizer-Biontech" vaccines in patients with comorbidities and immunocompromised patients (f-ratio averaged 4.7521, and 4.1682 as well as 11.7811, and 15.6 respectively, also p-value averaged 0.03492, and 0.04857, as well as both 0.003177, and 0.0009394 respectively, all