Dr. Lisa Law and Dr. Randy Taplitz share the latest evidence-based recommendations from ASCO on vaccines in adults with cancer. They discuss recommended routine preventative vaccinations, additional vaccinations and revaccinations for adults undergoing HSCT, CD19 CAR-T treatment, or B cell-depleting therapy, guidance for adults with cancer traveling outside the U.S., and recommendations for vaccination of household and close contacts of adults with cancer. Dr. Law and Dr. Taplitz also share their insights on the guideline, including the importance of this guideline for adults with cancer and their clinicians, future advances in research, and current unmet needs. Read the full guideline, "Vaccination of Adults with Cancer: ASCO Guideline" at www.asco.org/supportive-care-guidelines.

TRANSCRIPT

This guideline, clinical tools, and resources are available at http://www.asco.org/supportive-care-guidelines. Read the full text of the guideline and review authors' disclosures of potential conflicts of interest in the Journal of Clinical Oncology, https://ascopubs.org/doi/10.1200/JCO.24.00032

The ASCO Specialty Societies Advancing Adult Immunization (SSAAI) Project is supported by the Centers for Disease Control and Prevention (CDC) of the U.S. Department of Health and Human Services (HHS) as part of a financial assistance award to the Council of Medical Specialty Societies (CMSS) (with 100 percent funded by CDC/HHS). The contents are those of the authors and do not necessarily represent the official views of nor endorsement, by CDC/HHS or the U.S. Government.

Brittany Harvey: Hello, and welcome to the ASCO Guidelines Podcast, one of ASCO's podcasts delivering timely information to keep you up to date on the latest changes, challenges, and advances in oncology. You can find all the shows, including this one, at asco.org/podcasts.

My name is Brittany Harvey, and today, I am interviewing 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."

Thank you for being here, Dr. Law and Dr. Taplitz.

Dr. Lisa Law: Thank you.

Dr. Taplitz: Thank you, Brittany.

Brittany Harvey: Before we discuss this guideline, I'd like to take note that ASCO takes great care in the development of its guidelines and ensuring that the ASCO conflict of interest policy is followed for each guideline. The disclosures of potential conflicts of interest for the guideline panel, including Dr. Taplitz and Dr. Law, who have joined us here today, are available online with the publication of the guideline in the Journal of Clinical Oncology, which is linked in the show notes.

So then, to dive into the content, here first, Dr. Taplitz, can you provide a general overview of both the scope and purpose of this guideline on vaccination of adults with cancer?

Dr. Randy Taplitz: Yes, so people with cancer often experience a compromised immune system due to a variety of factors. This includes chronic inflammation, impaired or decreased function of the hematopoietic system, and treatments that compromise their immune function. Because of this, people with cancer are at a higher risk for infection, including with vaccine-preventable diseases. Also, response to vaccines in patients with cancer may well be affected by this underlying immune status, and their anticancer therapy, as well as the severity of the underlying malignancy. The purpose of vaccination in this group of patients is to prevent infection or to attenuate the severity of the disease when infection cannot be fully prevented.

This ASCO review builds on a 2013 guideline by the Infectious Diseases Society of America, or IDSA, and uses what's called a systematic literature review of 102 publications between 2013 and 2023. This includes 24 systematic reviews, 14 randomized clinical trials, and 64 non-randomized studies. The largest body of evidence in these studies, not surprisingly, addresses COVID vaccines on the efficacy and safety of vaccines used by adults with cancer or their household contacts. ASCO convened an expert panel to review this evidence and formulate recommendations for vaccinations in this population.

Brittany Harvey: Understood. I appreciate that context, Dr. Taplitz. So then, next, Dr. Law, I'd like to review the key recommendations of this guideline. The guideline addresses four overarching clinical questions. So starting with the first question, what are the recommended routine preventative vaccinations for adults with cancer?

Dr. Lisa Law: Thank you, Brittany. Before I start, I just want to wholeheartedly thank the first author of this paper, Dr. Mini Kamboj, Dr. Elise Kohn from the NCI, as well as the ASCO staff in putting this publication and guideline together. It is a very, very important guideline, and I echo everything Dr. Taplitz just said.

So going back to your question, what are the recommended routine preventative vaccines for adults with cancer? As per this guideline, there are about 7 to 8 based on patient age and risk. Namely, they are: seasonal flu, RSV for those aged 60 or above, COVID-19, Tdap, Hepatitis B, Shingrix, Pneumococcal vaccine, and the HPV vaccine. These vaccines should ideally be given two to four weeks before therapy. However, non-live vaccines can be given anytime during or after chemo, immunotherapy, hormonal treatment, radiation, or surgery.

Brittany Harvey: Excellent. Thank you for reviewing those vaccinations and the timing of them as well. So then, following those recommendations, Dr. Taplitz, what additional vaccinations and revaccinations are recommended for adults undergoing hematopoietic stem cell transplantation, CD19 CAR-T treatment, or B-cell depleting therapy?

Dr. Randy Taplitz: Many studies have shown that stem cell transplant recipients essentially lose immunity from childhood immunizations, and we know that these individuals are very vulnerable to infection, particularly in the first year after transplant. Revaccination is critical to help restore their immunity. The optimal timing of vaccination is based on our understanding of adequate immune reconstitution with B and T-cell recovery so that the individual can mount a response to the vaccine. We know that a lot of factors influence this immune reconstitution, including the age of the stem cell transplant recipient, the source of the donor, the time from transplant, graft-versus-host disease prophylaxis, the treatment and severity of graft-versus-host disease, and the vaccine type and antigens used.

There are a number of bodies throughout the world, IDSA as I mentioned, CDC, American Society for Transplant and Cellular Therapy, European Society for Blood and Marrow Transplant, and European Conference for Infections and Leukemia. All of these bodies have guidelines that approach vaccination in stem cell transplants. However, variation does exist in the use of a variety of things including whether to use immune predictors to help guide vaccination, and there is really not consensus on whether this immune predictor guided vaccination is more likely to produce a protective immune response versus a standardized schedule. In addition, the duration of protection is incompletely understood.

The bottom line in these guidelines is that they recommend complete revaccination starting for most vaccines at 6 to 12 months after stem cell transplant, in order to restore vaccine-induced immunity. And I just want to go through a few of the particulars. For COVID-19, which is a three-dose series in the primary series, influenza - generally high-dose influenza - and pneumococcal vaccine, PCV20 in general, ultimately four doses, can be administered, starting as early as three months after transplant. Although there is really not much data to guide the use of the recombinant zoster vaccine in allogeneic stem cell transplant, the vaccine can be administered after the end of antiviral prophylaxis, which in general is 12 to 18 months after allogeneic and 3 to 12 months after autologous stem cell transplant. Some of the other vaccines, such as hepatitis B, Tdap, meningococcal vaccines, and HPV revaccination in those less than 45 are also recommended.

I want to also spend the moment talking about the two recently licensed RSV vaccines, which were essentially studied in less compromised hosts and really without any immunogenicity data in stem cell transplant, and thus, there is no recommendation in this guideline for the use of these vaccines after transplant. Live vaccines, such as MMR and varicella – varicella would be in varicella-seronegative patients without a prior history of varicella – should be delayed for at least two years and only given in the absence of active graft-versus-host disease or immunosuppression.

Moving briefly to CAR T, which is an immunotherapy that involves adoptive cell therapy, given the available data and after a review by the group, it was recommended that adults with hematopoietic malignancies receiving CAR T therapy directed against B-cell antigens should receive influenza and COVID-19 vaccines either two weeks before lymphodepletion or no sooner than three months after the completion of therapy. Administration of non-live vaccines preferably should occur before CAR T treatment or at least 6 to 12 months after, following the same timing as what we recommend for stem cell transplant. There is really little data to guide the safety and timing of administration of live vaccines after CAR T therapy.

In terms of adults receiving B-cell depleting therapy, they are generally unable for time to mount an effective humoral response but may have at least partially intact cellular immune responses. They are encouraged to be revaccinated for COVID-19 no sooner than six months after completion of B-cell depleting therapy, and they should receive influenza vaccine approximately four weeks from the most recent treatment dose for patients on chronic therapy. For other non-seasonal immunizations, vaccines ideally should be given two to four weeks before commencing anti-CD20 therapy or delayed until 6 to 12 months after completion, except for the recombinant zoster vaccine, which can be given one month after the most recent dose of B-cell depleting therapy.

Brittany Harvey: I appreciate you reviewing each of those vaccinations and when they should be given, and reviewing the available data – albeit, limited data – in these situations.

So beyond these routine preventative vaccinations and revaccinations that you've both just described, Dr. Law, what additional vaccinations does the expert panel recommend for adults with cancer traveling outside the United States?

Dr. Lisa Law: Good question. As per these ASCO guidelines, adults with solid or blood cancer traveling outside of the United States should follow the CDC standard recommendations for their destination. For the 2024 CDC Yellow Book, travel vaccines, in general, should be delayed until three months from the last chemotherapy or, and for those with solid tumors, ideally when the disease is in remission. Of note, hepatitis A, typhoid, inactivated polio, Hep B, rabies, meningococcal vaccine, and Japanese encephalitis vaccines are considered to be safe. In all cases of travel, patients should be counseled by their healthcare provider about the travel timing, with the additional attention to the regional seasonality of infections, for instance, influenza is more common in late summer in Australia, and also with attention to any outbreaks that may be occurring globally at the time of travel.

Brittany Harvey: Absolutely. Those are key points for clinicians to discuss with their patients as they consider upcoming travel.

So then, the final clinical question that the panel addressed, Dr. Taplitz, what vaccinations does the panel recommend for household and close contacts of adults with cancer?

Dr. Randy Taplitz: Thank you. Yes, it is recommended that all household members and close contacts, when possible, be up to date on their vaccinations. And the only further thing I would say is that there are some special considerations for the use of live vaccines in household contacts, particularly in stem cell transplant recipients. Contacts of people who receive stem cell transplants should preferably receive inactivated influenza vaccines. As was mentioned, MMR and varicella vaccines are both safe to administer to close contacts. Vaccine strain transmission to immunocompromised hosts has not been associated with MMR use in family members.

Eleven cases of the varicella vaccine strain transmission are described in the published literature, but none occurred in compromised hosts. Because the vaccine strain can cause severe and fatal varicella in profoundly immunocompromised people, precautions are advised to avoid close contact with a person with a vaccine-induced rash. For household contact travelers, MMR and yellow fever vaccines are considered safe. Oral cholera should be avoided. For smallpox vaccines, the second-generation ACAM2000 has rarely been associated with vaccinia transmission and should be avoided because of this. But the live replication-deficient MVA-based JYNNEOS vaccine is felt to be safe for household contacts of immunocompromised individuals.

Brittany Harvey: I appreciate you reviewing the importance of vaccination for household and close contacts, and some of those precautions that individuals should take. I appreciate you both for reviewing all of these recommendations.

So then in your view, Dr. Law, what is the importance of this guideline, and how will it impact both clinicians and adults with cancer?

Dr. Lisa Law: In my opinion, this is a very important guideline that is long overdue in the oncology community and will have a huge impact on both clinicians and adults with cancer. Over the years, I have often been asked by my colleagues and patients, "Can I have the flu vaccine, and if so, when?" So this guideline really is going to be helpful. More importantly, our cancer patients are living much longer. They may have years of quality of life even with third or fourth line of treatment, especially, for instance, like CAR T for myeloma and lymphoma. However, we know that with additional treatment, that carries a substantial risk of infection complication among these immunocompromised patients. So it is of paramount importance to inform our patients and colleagues to be proactive in advocating preventive therapy ahead of time, meaning trying to get the patients appropriately vaccinated as early as possible to generate immunity.

Another case in point is the Shingrix vaccine. I used to see lots of shingles, but ever since we have the recombinant Shingrix, I have fewer encounters. And this is huge because post-herpetic neuralgia robs a patient's quality of life. So, again, it is very important to recommend appropriate vaccines for our cancer patients.

Brittany Harvey: Absolutely. It is key to ensure patients receive these preventative vaccines, and we hope that this guideline puts an emphasis on that for clinicians and patients.

So finally, to wrap us up, Dr. Taplitz, what are the current gaps in knowledge regarding the vaccination of people with cancer?

Dr. Randy Taplitz: There are a number of really important gaps in knowledge and really critical unmet needs that require research and other dedicated efforts. Among these are, and I think paramount, are really the participation of people with cancer with varied types of immunocompromise in vaccine trials. Where vaccine trials are only for cancer patients, obviously is ideal, testing vaccines in the appropriate population. But when that's not feasible, pre-existing cancer should not preclude eligibility, and inclusion of cohorts of people receiving anticancer treatment should be incorporated prospectively. So that's really critical because the quality of our guidelines is based upon the data. We use the data for developing guidelines and gathering more data in the particular patient population is really, really critical.

Secondly, work for creating more immunogenic vaccines and research to understand the immune response to vaccines after immuno-depleting therapies, particularly with newer therapies such as CAR T and newer B cell therapies, bispecific antibodies, etc. is really critical. We need to really understand the immune response and have the most potent vaccines available to these people who may have impaired immune responses.

Switching gears a little bit, we really need mechanisms to promote institutional commitment to integrate and sustain immunization best practices for people with cancer. This will largely be through multidisciplinary, team-based approaches, protocol-based vaccination standing orders, and leveraging data sharing so that we can all be on the same page with giving vaccines to these individuals. We also need education and evidence-based decision-making tools, emphasizing preventive care through immunization, the availability of educational resources to clinicians and patients to address commonly asked questions and also misconceptions about vaccination, that's absolutely critical.

And finally, I think we need to develop strategies for addressing unique challenges and factors contributing to vaccine hesitancy during cancer therapy. We need to focus on patient and clinician communication, and very importantly, we need to consider health equity considerations in the development and approach to vaccines in these compromised patients.

Brittany Harvey: Definitely, we'll look forward to research and advances in these areas that you've just described to support these guidelines and increase vaccine uptake.

So I want to thank you both so much for your work on this important guideline, and thank you for your time today, Dr. Law and Dr. Taplitz.

Dr. Lisa Law: Thank you.

Brittany Harvey: And thank you to all of our listeners for tuning in to the ASCO Guidelines podcast. To read the full guideline, go to www.asco.org/supportive-care-guidelines. You can also find many of our guidelines and interactive resources in the free ASCO Guidelines app, available in the Apple App Store or the Google Play Store. If you have enjoyed what you've heard today, please rate and review the podcast, and be sure to subscribe so you never miss an episode.

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