Vaccination opportunities in multiple sclerosis patients treated with cladribine tablets

The COVID-19 pandemic and the mass vaccination campaign highlighted the situation of the most vulnerable patients. In this work, we focused attention on patients who have Multiple Sclerosis (MS), particularly in treatment with cladribine tablets, trying to understand if and when it is possible to administer the vaccine successfully. Considering the innovative topic, we reviewed the existing literature with an analysis of the experiences also related to other vaccinations, including influenza and VZV, and very recent data from countries with vaccination campaigns already advanced. Overall, we have taken into account the mechanism of action, the pharmacokinetic/pharmacodynamic of cladribine and the changes in the immune system after its administration, together with the preliminary data about the humoral response to influenza, VZV and SARS-CoV-2 vaccinations in cladribine treated patients. In conclusion, data showed that the use of cladribine tablets seems to permit flexibility regarding vaccination timing and we suggest that vaccination in those patients should be safe and effective. The current COVID 19 pandemic has re-ignited the interest in vaccines and vaccination procedures. The importance of including fragile individuals has increased as a result of mass vaccination. Millions of patients with multiple sclerosis (MS) around the world are debating whether they can safely receive their vaccine shot with the same efficacy despite receiving immune-modulating or immune-suppressive treatments. In the absence of conclusive empirical data, we will review and discuss the available evidence and the reasonable conclusions for one specific treatment, namely cladribine tablets (Mavenclad).