The effect of corticosteroid on immunogenicity of SARS-CoV-2 vaccines in solid cancer patients.

127 Background: Corticosteroids are known to diminish immune response ability, which is generally used in routine pre-medication for chemotherapy. The intersecting of timeframe between the corticosteroid’s duration of action and peak COVID-19 vaccine efficacy could impair vaccine immunogenicity. Thus, inquiring about corticosteroids affecting the efficacy of vaccines, a dose of corticosteroids, and optimal timing of vaccination to promote effective immunity in this population is needed. Methods: This was a prospective longitudinal observational cohort study that enrolled solid cancer patients classified into dexamethasone and non-dexamethasone receiving groups. All participants were immunized with two doses of ChAdOx1 nCoV-19 or CoronaVac vaccines. This study's purpose was to compare corticosteroid's effect on immunogenicity responses to the SARS-CoV-2 S protein in solid cancer patients following two doses of COVID-19 vaccine in the dexamethasone and non-dexamethasone group. Secondary outcomes included the post-immunization anti-S IgG seroconversion rate, the association of corticosteroid dosage, time duration and immunogenicity level. Results: Among the 161 enrolled solid cancer patients, 71 and 90 were in the dexamethasone and non- dexamethasone groups, respectively. The median anti-S IgG titer after COVID-19 vaccination in the dexamethasone group was lower than non- dexamethasone group with a statistically significant difference (47.22 vs 141.09 U/ml, p = 0.035). The anti-S IgG seroconversion rate was also significantly lower in the dexamethasone group than in the non- dexamethasone group (93.83% vs 80.95% p = 0.023). The lowest median anti-SARS-CoV-2 IgG titer level at 7.89 AU/ml showed in patients with the highest dose of steroid group (37 mg or more of dexamethasone) and patients who were injected with COVID-19 vaccines on the same day of receiving dexamethasone, 25.41 AU/ml. Conclusions: Solid cancer patients vaccinated against COVID-19 while receiving dexamethasone had lower immunogenicity responses than those who got vaccines without dexamethasone, regardless of active cancer treatment types.The direct association between immunogenicity level and steroid dosage, as well as length of duration from vaccination to dexamethasone was observed. Clinical trial information: TCTR20221001004 .