Why are vaccines important for cancer patients?
Cancer patients are often in a vulnerable immunologic state, due to a variety of factors. When speaking of blood cancers, this is a common issue amongst patients because the immune cells are produced in the bone marrow and circulate in the bloodstream to fight infections or detect abnormal cells. In blood cancers, this balance is often disrupted because the growth of abnormal cancer cells sometimes occupies the bone marrow or the affected cells are immune system cells.
What factors weaken the immune system of cancer patients?
Chronic inflammation
Hematopoietic stem cell transplant
CAR-T cell therapy
B-cell depleting therapy (a process that destroys malignant B-cells)
Impaired or diminished function of immune system cells
Treatments that debilitate the immune system like corticosteroid
Preventing infections in patients with a vulnerable immune system is fundamental. Several prevention strategies exist, like antibiotics or antiviral agents, but one of the most effective tactics since 1796 was vaccination when the smallpox vaccine was developed, and many lives were saved.
Optimizing vaccination should be considered a key element for cancer patients
Vaccination is an important measure to avoid infection-associated illness or death among patients with a weakened immune system.
A recent interview by ASCO with Dr. Lisa Law from Kaiser Permanente and Dr. Randy Taplitz from City of Hope Comprehensive Cancer Center, authors on “Vaccination of Adults with Cancer: ASCO Guideline.”
The doctors conducted a systematic review, analyzing over a hundred publications between 2013 and 2023, including randomized controlled trials and non-randomized studies, many of which the more recent studies contained information on COVID-19 vaccines. They did a compilation of recommendations based on evidence to create vaccination guidelines for cancer patients.
For vaccines, timing is key
Dr. Taplitz stated that for cancer patients, responding to vaccines can be affected by their immune status and their anticancer therapy, as well as the severity of the underlying cancer. The purpose of vaccination is to prevent infection or reduce the severity of the infection in case it can’t be prevented.
Dr. Law mentioned the recommended vaccines for cancer patients based on age and risk:
Category | Recommended based on age and risk | Non-live vaccines | Revaccination |
Vaccine Type / Description | Seasonal flu, RSV, COVID-19, T-dap, Hepatitis B, Shingrix, Pneumococcal vaccine, HPV vaccine | influenza, polio (IPV), rabies, hepatitis A and pertussis | Childhood vaccines or additional vaccinations and revaccinations for hematopoietic stem cell transplantation, CD19 CAR-T treatment, or B-cell depleting therapy users. |
Timing / Recommendation | 2-4 weeks before therapy | Anytime during or after chemo, immunotherapy, hormonal treatment, radiation, or surgery | • First year after treatment and after measuring the patient's adequate immune recovery. • COVID-19 vaccine revaccination after 6 months of B-cell depleting therapy • Influenza vaccine 4 weeks from the most recent treatment on patients with chronic therapy |
Procedures like CAR-T cell therapy or B-cell depletion therapy help patients with blood cancer but significantly impact their immune systems because they " erase” the body’s immune memory, and revaccination helps the immune system “remember” how to fight against infections that are a threat to non-vaccinated people.
Dr. Randy Taplitz discussed the recommended timing of revaccination in patients according to the treatment stage, highlighting the important role of vaccines in restoring immunity.
Therapy Type | Timing & Revaccination Guidelines | Specific Recommendations |
Stem cell transplant | • Wait 6–12 months before receiving most vaccines • Complete revaccination starting 6–12 months after | • Live vaccines like varicella should be delayed for at least two years after transplant and only to patients who have never had varicella before • Recombinant zoster vaccine after finishing acyclovir prophylaxis (12–18 months after allogeneic transplant and 3–12 months after autologous stem cell transplant) |
CAR-T cell therapy | Vaccination should ideally be given before any planned cancer treatment by 2–4 weeks | • Non-live vaccines (like rabies, flu or hepatitis A) are recommended before initiating CAR-T treatment or at least 6–12 months after • Influenza and COVID-19 vaccines should be given either 2 weeks before CAR-T therapy or after 3 months of completion |
B-cell depleting therapy | This therapy, like CAR-T cell therapy requires revaccination, and seasonal vaccines before starting | • Revaccination for COVID-19 only after 6 months of completing the treatment • Non-live vaccines are recommended even if the response may be milder • Varicella vaccine is recommended if the patient never had varicella before, but it should be delayed for at least two years and only be given in the absence of graft-versus-host disease or immunosuppression |
What vaccines should I get if I want to travel?
Dr. Lisa Law mentions that following the CDC standard recommendations for the destination is sufficient when traveling outside the United States. However, vaccinations should be delayed until 3 months after the last round of chemotherapy. Dr. Law states that it is important to receive advice from your oncologist in all cases of travel to determine the best timing and to ensure you are not traveling to a location with a regional outbreak.
Should my loved ones vaccinate with me?
According to the updated recommendations, Dr. Randy Taplitz mentions that all household members and close contacts should be updated on their vaccinations. Vaccines like inactivated influenza, MMR (measles, mumps, and rubella), and varicella are safe to administer to close contacts.
What can help improve vaccine research?
Over time, vaccines have been proven to eradicate life-threatening diseases, and following the vaccination guidelines can protect vulnerable populations. Dr. Randy addresses powerful information regarding gaps in knowledge, such as the lack of perceived benefits from vaccines and unmet needs like vaccine costs and accessibility. He emphasizes the need for further research and dedicated efforts, mentioning that more cancer patient data is needed for developing more precise vaccine guidelines.
You can also contribute to life-saving research through HealthTree Cure Hub by creating an account and responding to our vaccination survey. Being aware of your health status and vaccination history leads to improved self-advocacy and better disease outcomes!
