Dear ERIC Members,

In light of the recent developments related to the approval and roll-out of vaccines against SARS-CoV-2, ERIC would like to provide guidance on the use of the SARS-CoV-2 vaccines in patients with chronic lymphocytic leukemia (CLL).

Available data show that the current SARS-CoV-2 vaccines (covering mRNA, replication deficient and inactivated vaccine technologies) have high efficacy and a favorable safety profile with rare serious adverse events.

Approved or close to approval vaccines against SARS-CoV-2 are not classified as live attenuated vaccine, and therefore they can be administered safely even in immunocompromised patients as most patients with CLL, even though the level of protection achieved after vaccination remains to be defined. 

Vaccination is particularly beneficial in individuals with an increased risk of a severe course of COVID-19 and increased risk of mortality, and retrospective studies have documented that patients with CLL are more prone to unfavorable COVID-19 course if hospitalized with severe disease.

For these reasons, ERIC recommends vaccination against SARS-CoV-2 for patients with CLL.

Due to the potential immunosuppressive properties of different agents used to treat CLL, every effort should be done to vaccinate patients who plan to receive a SARS-CoV-2 vaccine (mRNA, replication deficient or inactivated) prior to starting/initiating treatment unless a delay in treatment initiation is clinically unacceptable.


Shared and individualised decision-making based on a patient’s SARS-CoV-2 infection/complication risk, the general condition of the patient, the severity and seriousness of the underlying disease/condition is always advised. SARS-CoV-2 vaccines should be given in accordance with the approved/authorized vaccine label and official immunization guidance. Patients should still protect themselves from exposure to SARS-CoV-2 after vaccination.