What is a vaccine? 

A vaccine is a small amount of a virus or bacteria that has been weakened or killed. Exposing the body to it teaches the body to recognize and attack the infection if exposed to it later in life. This helps an individual not become ill or have less of an infection if exposed to the pathogen. 

Why do CLL patients need vaccines? 

CLL patients have a higher risk of contracting infections from viruses and bacteria because of their weakened immune systems. Patients are encouraged to receive non-live vaccines before receiving treatment to help protect the immune system. 

Types of vaccines

• Live virus vaccines (CLL patients should never receive a live virus version of a vaccine. If a type of disease vaccine is needed that is usually distributed live, they should review receiving a non-live version) 
  • Uses a weakened (attenuated) form of the virus
    • Examples: Measles, mumps, influenza, poliovirus, rotavirus, rubella (MMR), and varicella (chickenpox) vaccines
• Inactivated (killed) vaccine
  • Made from a small piece of the virus/bacteria 
    • Example: Whooping cough (pertussis) vaccine
• Toxoid vaccines
  • Contains a toxin/chemical made by the bacteria or virus making the person immune to the effects of the infection 
    • Examples: Diphtheria and tetanus vaccines
• Biosynthetic vaccines 
  • A manmade substance that is similar to the piece of virus or bacteria
    • Example: Hepatitis B vaccine
• mRNA vaccines 
  • Contain the genetic code of the virus the body can use to create antibodies to fight the virus 
    • Example: Some SARS-CoV2 vaccines

Vaccines Before Treatment

CLL patients who are not receiving treatment such as those in watch and wait or are preparing to start treatment should receive the following non-live vaccines in order to prevent infections: 

• Influenza vaccine every year - not the live type
• Pneumococcal polysaccharide vaccine (PPSV23) every 5 years or when prescribed by the doctor. If you haven't yet received PPSV23, you may get the pneumococcal conjugate vaccine (PCV20) first
• Ecombinant, adjuvanted zoster vaccine for shingles prevention

• COVID-19 vaccines
  • Your doctor may prescribe tixagevimab and cilgavimab (Evusheld) to prevent severe COVID-19

Vaccination Reactions During Treatment

venetoclax + obinutuzumab/rituximab

CLL patients currently receiving or who have just stopped treatment with venetoclax + obinutuzumab/rituximab should not receive any vaccines without a doctor’s approval. This is because the medicines can lower the body’s resistance and the vaccine may cause the patient to get the infection the vaccine was trying to prevent. These patients should also limit time spent around individuals in the home who have just received a live virus vaccine as the virus could be passed to the patient.

BTK inhibitors

Patients who are going to start a BTK inhibitor should receive any needed non-live vaccinations at least two weeks before the start of treatment. This is because BTKis can reduce the effectiveness of vaccines if administered during treatment. If a patient is vaccinated with a non-live vaccine during therapy, they should revaccinate at least three months after stopping the BTKi. Consult with your CLL specialist about any questions you have related to vaccines. 

Managing Reactivated Viruses 

CLL medicines may cause certain viruses to be reactivated. The below list includes antiviral medicines you may receive from your doctor to help prevent and/or manage reactivated viruses: 

• Herpes virus 
  • Prevent with acyclovir
• Pneumocystis jiroveci pneumonia 
  • Prevent with sulfamethoxazole or trimethoprim

• Hepatitis B virus reactivation
  • Prevent or treat with entecavir or other antivirals
• Cytomegalovirus reactivation
  • Take ganciclovir if the virus is present or rising
• Hepatitis C virus
  • Treat with direct-acting antiviral agents

Managing Infections 

CLL patients are at risk of frequent infections that may affect areas like the ears, sinuses, or lungs. Doctors can help patients reduce infections with medicines like antibiotics. If a patient has an IgG level of less than 500mg/dL, they can receive an immunoglobulin infusion each month. 

If you have any questions related to vaccines, medicines to manage re-activated viruses, and managing infections, please contact your CLL specialist. If you need help finding a CLL specialist, visit HealthTree's CLL specialist directory here.