COVID-19 Vaccination in Cancer Patients: A Review Article.

Coronavirus disease 2019 (COVID-19) infection is caused by severe acute respiratory syndrome coronavirus 2. Adults with cancer are immunocompromised due to several causes including cancer itself and immunosuppressive therapy. Thus, cancer patients are more susceptible to develop COVID-19 infection. As COVID-19 vaccines became available, patients with cancer would benefit from receiving the vaccine. This article aims to review the recent evidences and recommendations about COVID-19 vaccination in cancer patients.Current guidelines recommend that patients with cancer should have the priority to receive the vaccine given their immunocompromised state. The timing of administration varies depending on cancer type and treatment. Generally, the vaccine should be given before starting the chemotherapy if possible or in between chemotherapy cycles and away from nadir phase. For other cancer treatments, it is recommended to give the vaccine when there is evidence of blood count recovery. In general, induction therapy and treatment for newly diagnosed patients should not be delayed for the vaccination purpose. It is noteworthy to mention that cancer patients especially those with hematologic malignancies might have absented or attenuated response to the vaccine due to their pathophysiological status.On the other hand, the current vaccine guidelines have been criticized for lacking evidence on some important topics that need to be addressed. Firstly, some vaccines have been granted an emergency use authorization, prior to the usual comprehensive safety and efficacy evaluation process. Secondly, specific populations including cancer patients were excluded from the approval trials for safety reasons. Finally, some recommendations regarding the COVID-19 vaccines are extrapolated from other vaccines studies. Further studies are required to fill these gaps and observational studies that include cancer patients are warranted to have a better understanding of the safety and efficacy of the vaccines in cancer patients.

Hypogammaglobulinemia is associated with reduced antibody response after anti-SARS-CoV-2 vaccination in MS patients treated with antiCD20 therapies.

BACKGROUND: COVID-19 vaccination is highly recommended to multiple sclerosis (MS) patients. Little is known about the role of patients' clinical and demographic characteristics in determining antibody response. METHODS: We evaluated safety and efficacy of anti-SARS-CoV-2 vaccines on 143 included MS patients. Then, we analyzed antibody titer in a subgroup, assessing clinical and demographic variables associated with protection and antibody titer. RESULTS: After completing the vaccination cycle, the rate of local adverse events was similar after the first and second dose. A higher proportion of systemic AEs was reported after the second dose (65.7% vs 24.5% after the first dose). Antibody response was evaluated in 97 patients. Higher EDSS (OR 0.6, 95% CI 0.4-0.9, p = 0.006) and treatment with antiCD20 (OR 0.02, 95% CI 0.003-0.098, p 0.001) were associated with a lower chance of having an efficacious response. Higher weight was associated with higher Ab titer (ß = 15.2, 95% CI 2.8-27.6, p = 0.017), while treatment with antiCD20 with lower titers (ß = - 1092.3, 95% CI - 1477.4 to - 702.2, p < 0.001). In patients treated with antiCD20, hypogammaglobulinemia (ß - 543, 95% CI - 1047.6 to - 39.1, p = 0.036) and treatment duration (ß - 182, 95% CI - 341.4 to - 24.3, p = 0.027) were associated with lower Ab titer. CONCLUSION: Our study confirms that COVID-19 vaccination in MS patient is safe and effective in preventing symptomatic COVID-19 and should be recommended to all patients. Moreover, we suggest a possible role of hypogammaglobulinemia in reducing Ab response in patients treated with antiCD20 therapies.