Vaccination of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient

Immunity Against Measles in Korean Autologous Hematopoietic Stem Cell Transplant Recipients

The seropositivity of measles antibodies among 261 autologous stem cell transplant recipients (ASCTs) in Korea, assessed approximately 1-2 years after transplant (median, 11 months; interquartile range, 9-14), was significantly lower than age- and sex-matched control healthcare workers (83.1% [217/261] vs. 90.3% [539/597], P = 0.002). The findings underscore the vulnerability of adult ASCT recipients to measles. Clinicians should prioritize testing for measles IgG after ASCT and consider vaccination for ASCT recipients who remain seronegative 2 years after ASCT.

Consensus document of the Spanish Society of Paediatric Infectious Diseases and the Advisory Committee on Vaccines of the Spanish Association of Pediatrics for vaccination of immunosuppressed individuals

The number of people with immunosuppression is increasing considerably due to their greater survival and the use of new immunosuppressive treatments for various chronic diseases. This is a heterogeneous group of patients in whom vaccination as a preventive measure is one of the basic pillars of their wellbeing, given their increased risk of contracting infections. This consensus, developed jointly by the Sociedad Española de Infectología Pediátrica (Spanish Society of Pediatric Infectious Diseases) and the Advisory Committee on Vaccines of the Asociación Española de Pediatría (Spanish Association of Paediatrics), provides guidelines for the development of a personalised vaccination schedule for patients in special situations, including general recommendations and specific recommendations for vaccination of bone marrow and solid organ transplant recipients, children with inborn errors of immunity, oncologic patients, patients with chronic or systemic diseases and immunosuppressed travellers.

Vaccinations in children with hematologic malignancies and those receiving hematopoietic stem cell transplants or cellular therapies

Children who are immune compromised are uniquely threatened by a higher risk of infections, including vaccine-preventable diseases (VPDs). Children who undergo chemotherapy or cellular therapies may not have preexisting immunity to VPDs at the time of their treatment including not yet receiving their primary vaccine series, and additionally they have higher risk of exposures (e.g., due to family structures, daycare and school setting) with decreased capacity to protect themselves using nonpharmaceutic measures (e.g., masking). In the past, efforts to revaccinate these children have often been delayed or incomplete. Treatment with chemotherapy, stem cell transplants, and/or cellular therapies impair the ability of the immune system to mount a robust vaccine response. Ideally, protection would be provided as soon as both safe and effective, which will vary by vaccine type (e.g., replicating versus nonreplicating; conjugated versus polysaccharide). While a single approach revaccination schedule following these therapies would be convenient for providers, it would not account for patient specific factors that influence the timing of immune reconstitution (IR). Evidence suggests that many of these children would mount a meaningful vaccine response as early as 3 months following completion of treatment. Here within, we provide updated guidance on how to approach vaccination both during and following completion of these therapies.

Quality Improvement Initiative to Improve Time and Adherence to Revaccination after Hematopoietic Cell Transplantation: Implementation of a Revaccination Clinic within the Transplantation Program

Revaccination after hematopoietic cell transplantation (HCT) is critical to prevent morbidity and mortality from vaccine-preventable illnesses. The global aim of our quality improvement initiative was to enhance timely, correct, and effective revaccination after pediatric HCT. The SMART aim of our project was to decrease median unvaccinated time by 4 months by decreasing the time to vaccine eligibility, time from eligibility to vaccine initiation, and time to completion of the vaccine series. A multidisciplinary group performed a cross-sectional quantitative and qualitative evaluation of revaccination practices at our institution. We identified factors associated with delayed, incorrect, or incomplete revaccination. Several plan-do-study-act interventions were implemented to address these drivers, including revising immune readiness criteria, increasing auditing of primary care administered immunizations, and, importantly, establishing a dedicated revaccination clinic within the HCT clinic at our center. The time to vaccine eligibility decreased from 12.6 months to 10 months (a 20% decrease), and the time to complete the vaccine series decreased from 19.3 months to 15.7 months (a 19% decrease). With a quality improvement initiative, we addressed the many causes of delayed or incomplete revaccination post-HCT and through a team-based approach successfully decreased the time to vaccine start and time to vaccine completion at our center.

Respiratory Viral Infections in Recipients of Cellular Therapies: A Review of Incidence, Outcomes, Treatment, and Prevention

Respiratory viral infections (RVIs) are of major clinical importance in immunocompromised patients and represent a substantial cause of morbidity and mortality in patients with hematologic malignancies and those who have undergone hematopoietic cell transplantation. Similarly, patients receiving immunotherapy with CD19-targeted chimeric antigen receptor-modified T cells, natural killer cells, and genetically modified T-cell receptors are susceptible to RVIs and progression to lower respiratory tract infections. In adoptive cellular therapy recipients, this enhanced susceptibility to RVIs results from previous chemotherapy regimens such as lymphocyte-depleting chemotherapy conditioning regimens, underlying B-cell malignancies, immune-related toxicities, and secondary prolonged, profound hypogammaglobulinemia. The aggregated risk factors for RVIs have both immediate and long-term consequences. This review summarizes the current literature on the pathogenesis, epidemiology, and clinical aspects of RVIs that are unique to recipients of adoptive cellular therapy, the preventive and therapeutic options for common RVIs, and appropriate infection control and preventive strategies.

Antibody Response against Vaccine Antigens in Children after TCRαβ-Depleted Haploidentical Stem Cell Transplantation: Is It Similar to That in Recipients with Fully Matched Donors?

Recipients of hematopoietic stem cell transplantation (HSCT) with HLA-mismatched donors are more immune suppressed than those with fully matched donors. The immunologic response to vaccines also may differ in HLA-mismatched haploidentical HSCT recipients. In this study, we aimed to evaluate the antibody response to vaccines in pediatric TCRαβ-depleted haploidentical HSCT recipients. This longitudinal study included a study group of 21 children who underwent haploidentical HSCT without CD19 depletion and with TCRαβ depletion and a control group of 38 children who underwent fully matched donor HSCT. Antibody levels were quantified by serologic tests before vaccination and after each dose against tetanus, diphtheria, pneumococcus, hepatitis B, hepatitis A, measles, rubella, mumps, and varicella. The median recipient age was significantly lower (P = .037) and the median donor age was significantly higher (P = .000) in the haploidentical group compared with the fully matched group. At the months 1, 3, 6, 9 and 12 post-transplantation, the median CD4, CD8, and CD19 cell counts and lymphocyte counts were similar in the haploidentical and fully matched groups. The median natural killer cell count was higher in the haploidentical group at the months 1, 3, and 6 post-transplantation (P = .001, .006, and .004, respectively). The median time to first vaccination was similar in the 2 groups (12.5 [range, 11 to 14] months for the haploidentical group and 11 [range, 9 to 13] months for the fully matched group; P = .441). Seroprotection rates were 100% in both groups after the second and third doses of diphtheria vaccine, the third dose of tetanus vaccine, the third dose of hepatitis B vaccine, the second and third doses of pneumococcal conjugate vaccines (PCV13), and pneumococcal polysaccharide vaccine (PSPV23), although lower after the initial doses and before vaccination. Seroprotection for hepatitis A, rubella, and varicella was >90% in the fully matched group and 100% for the haploidentical group after the second doses. Measles and mumps seroprotection rates were >80% in the haploidentical group and approximately 70% for the fully matched group after the second dose. Antibody response and seroprotection rates against vaccine antigens were similar in the haploidentical group and the fully matched when revaccination was started at 12 months post-transplantation. These findings support the idea that TCRαβ-depleted haploidentical HSCT recipients can be revaccinated according to the same vaccination schedule as fully matched HSCT recipients. Revaccination earlier after transplantation and vaccine responses for recipients of different types of HSCT should be evaluated in future studies.

Frequently Asked Questions on Coronavirus Disease 2019 Vaccination for Hematopoietic Cell Transplantation and Chimeric Antigen Receptor T-Cell Recipients From the American Society for Transplantation and Cellular Therapy and the American Society of Hematology

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), disproportionately affects immunocompromised and elderly patients. Not only are hematopoietic cell transplantation (HCT) and chimeric antigen receptor (CAR) T-cell recipients at greater risk for severe COVID-19 and COVID-19-related complications, but they also may experience suboptimal immune responses to currently available COVID-19 vaccines. Optimizing the use, timing, and number of doses of the COVID-19 vaccines in these patients may provide better protection against SARS-CoV-2 infection and better outcomes after infection. To this end, current guidelines for COVID-19 vaccination in HCT and CAR T-cell recipients from the American Society of Transplantation and Cellular Therapy Transplant Infectious Disease Special Interest Group and the American Society of Hematology are provided in a frequently asked questions format.

Safety and Tolerability of SARS-CoV2 Emergency-Use Authorized Vaccines for Allogeneic Hematopoietic Stem Cell Transplant Recipients

The safety and efficacy of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) emergency-use authorized (EUA) vaccines have been confirmed in the general population. However, there are no data on its safety and tolerability or efficacy in recipients of allogeneic hematopoietic stem cell transplant (HCT). We performed this study to identify the incidence of adverse events following SARS-CoV2 EUA vaccines, the incidence of new-onset graft-versus-host disease (GVHD) or worsening of existing GVHD after EUA vaccine administration, and the incidence SARS-CoV2 positivity in vaccinated HCT patients. We retrospectively reviewed 113 HCT patients who received at least one dose of EUA vaccine to describe the safety and tolerability, any impact on GVHD, and the incidence of SARS-CoV2 PCR positivity after vaccination. Patients received either Pfizer (BNT162b2) or Moderna (mRNA-1273) vaccines. Patients were included if they were 18 years or older and had received at least one dose of vaccine in the post-HCT setting. Most patients presented with myalgias/arthralgias (first dose, 7.7%; second dose, 14.6%), fatigue (first dose, 15.4%; second dose, 29.2%), and injection site pain (first dose, 40.4%; second dose, 43.8%). Other side-effects experienced by patients included nausea, vomiting, diarrhea, headache, and injection-site rash and swelling. Liver function abnormalities occurred in 18.6% of patients. Neutropenia, thrombocytopenia, and lymphopenia occurred in 13.3%, 11.5%, and 8.8% of patients, respectively. Forty percent of patients had active chronic GVHD at the time of vaccination, and worsening chronic GVHD occurred in 3.5% of the patients. New chronic GVHD developed in 9.7% of patients after vaccination. The SARS-CoV2 EUA vaccines were well tolerated in allogeneic HCT recipients.

Disease- and Therapy-Specific Impact on Humoral Immune Responses to COVID-19 Vaccination in Hematologic Malignancies

Coronavirus disease-19 (COVID-19) vaccine response data for patients with hematologic malignancy, who carry high risk for severe COVID-19 illness, are incomplete. In a study of 551 hematologic malignancy patients with leukemia, lymphoma, and multiple myeloma, anti-SARS-CoV-2 spike IgG titers and neutralizing activity were measured at 1 and 3 months from initial vaccination. Compared with healthy controls, patients with hematologic malignancy had attenuated antibody titers at 1 and 3 months. Furthermore, patients with hematologic malignancy had markedly diminished neutralizing capacity of 26.3% at 1 month and 43.6% at 3 months, despite positive seroconversion rates of 51.5% and 68.9% at the respective time points. Healthy controls had 93.2% and 100% neutralizing capacity at 1 and 3 months, respectively. Patients with leukemia, lymphoma, and multiple myeloma on observation had uniformly blunted responses. Treatment with Bruton tyrosine kinase inhibitors, venetoclax, phosphoinositide 3-kinase inhibitors, anti-CD19/CD20-directed therapies, and anti-CD38/B-cell maturation antigen-directed therapies substantially hindered responses, but single-agent immunomodulatory agents did not.

Significance

Patients with hematologic malignancy have compromised COVID-19 vaccine responses at baseline that are further suppressed by active therapy, with many patients having insufficient neutralizing capacity despite positive antibody titers. Refining vaccine response parameters is critical to guiding clinical care, including the indication for booster vaccines, for this vulnerable population.See related article by Tamari et al., p. 577. This article is highlighted in the In This Issue feature, p. 549.

South Asian Declaration-Consensus Guidelines for COVID-19 Vaccination in Cancer Patients

We provide the South Asian Declaration, containing the consensus guidelines for coronavirus disease 2019 (COVID-19) vaccination in cancer patients.

Administration of COVID-19 vaccines in immunocompromised patients

Since the beginning of vaccination programs against COVID-19 in different countries, several populations such as patients with specific immunological conditions have been considered as the priorities for immunization. In this regard, patients with autoimmune diseases or those receiving immunosuppressive agents and anti-cancer therapies, need special attention. However, no confirmed data is presently available regarding COVID-19 vaccines in these populations due to exclusion from the conducted clinical trials. Given the probable suppression or over-activation of the immune system in such patients, reaching a consensus for their vaccination is critical, besides gathering data and conducting trials, which could probably clarify this matter in the future. In this review, besides a brief on the available COVID-19 vaccines, considerations and available knowledge about administering similar vaccines in patients with cancer, hematopoietic stem cell transplantation, solid organ transplantation, multiple sclerosis (MS), inflammatory bowel disease (IBD), and rheumatologic and dermatologic autoimmune disorders are summarized to help in decision making. As discussed, live-attenuated viruses, which should be avoided in these groups, are not employed in the present COVID-19 vaccines. Thus, the main concern regarding efficacy could be met using a potent COVID-19 vaccine. Moreover, the vaccination timing for maximum efficacy could be decided according to the patient’s condition, indicated medications, and the guides provided here. Post-vaccination monitoring is also advised to ensure an adequate immune response. Further studies in this area are urgently warranted.

Safety and Immunogenicity of the BNT162b2 mRNA COVID-19 Vaccine in Patients after Allogeneic HCT or CD19-based CART therapy-A Single-Center Prospective Cohort Study

Data are scarce regarding both the safety and immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in patients undergoing immune cell therapy; thus, we prospectively evaluated these two domains in patients receiving this vaccine after allogeneic hematopoietic cell transplantation (HCT; n = 66) or after CD19-based chimeric antigen receptor T cell (CART) therapy (n = 14). Overall, the vaccine was well tolerated, with mild non-hematologic vaccine-reported adverse events in a minority of the patients. Twelve percent of the patients after the first dose and 10% of the patients after the second dose developed cytopenia, and there were three cases of graft-versus-host disease exacerbation after each dose. A single case of impending graft rejection was summarized as possibly related. Evaluation of immunogenicity showed that 57% of patients after CART infusion and 75% patients after allogeneic HCT had evidence of humoral and/or cellular response to the vaccine. The Cox regression model indicated that longer time from infusion of cells, female sex, and higher CD19⁺ cells were associated with a positive humoral response, whereas a higher CD4⁺/CD8⁺ ratio was correlated with a positive cellular response, as confirmed by the ELISpot test. We conclude that the BNT162b2 mRNA COVID-19 vaccine has impressive immunogenicity in patients after allogeneic HCT or CART. Adverse events were mostly mild and transient, but some significant hematologic events were observed; hence, patients should be closely monitored.

Cocooning against COVID-19: The argument for vaccinating caregivers of patients with cancer

Current national COVID‐19 vaccination guidelines and recommendations focus vaccine guidance on patients with cancer. In this COVID‐19 vaccination race, “cocoon vaccination” strategies, which include informal caregivers and household contacts as priority groups for SARS‐CoV‐2 vaccination, could be an additional strategy used to protect patients with cancer who may have limited immune responses to current vaccinations. Medical systems specializing in cancer care should support education and vaccination campaigns which target informal caregivers and household contacts in addition to cancer patients.

COVID-19 Vaccines: Preparing for Vaccination in the Context of Clinical Oncology Care

BACKGROUND

In the environment of an infectious pandemic, vaccines are a primary public health strategy to prevent the spread of disease. With the COVID-19 pandemic, there is heightened interest in safe and effective vaccines and their use in the context of clinical oncology practice.

OBJECTIVES

This article provides foundational information about vaccines in general and vaccines developed to protect against the SARS-CoV-2 virus in the United States, as well as clinical nurse strategies to apply vaccines in clinical oncology practice.

METHODS

The article is based on a review of public health literature and reputable websites about vaccines and their development in clinical care.

FINDINGS

This foundational information about vaccines reviews their history and development, as well as the development of COVID-19 vaccines specifically, and discusses COVID-19 vaccines as part of clinical oncology care. Supporting best practices in clinical oncology care, nurses can provide factual, evidence-based information about vaccine safety, effectiveness, and safe administration.

Casting a wider protective net: Anti-infective vaccine strategies for patients with hematologic malignancy and blood and marrow transplantation

Patients who have hematologic malignancies are at high risk for infections but vaccinations may be effective prophylaxis. The increased infection risk derives from immune defects secondary to malignancy, the classic example being CLL, and chemotherapies and immunotherapy used to treat the malignancies. Therapy of hematologic malignancies is being revolutionized by introduction of novel targeted agents and immunomodulatory medications, improving the survival of patients. At the same time those agents uniquely change the infection risk and response to immunizations. This review will summarize current vaccine recommendations for patients with hematologic malignancies including patients who undergo hematopoietic cell transplant.

Adherence to Immunization: Rebuttal of Vaccine Hesitancy

Immunizations have been saving the lives of millions of people since they were first used by Edward Jenner in 1796, and new vaccines are being developed all the time. Hopefully, a new vaccine for coronavirus disease 2019 (COVID-19) will be developed in the near future, and perhaps even one for human immunodeficiency virus. Although the effectiveness of vaccinations has been proven over the years and adverse effects to currently available vaccinations are extremely rare, many people continue to defer immunizations for themselves and their families. According to the World Health Organization (WHO), this phenomenon, known as "vaccine hesitancy," is a major public health problem globally. This review summarizes the unproven adverse effects of various vaccines and stresses the importance of enforcing vaccination policies to minimize vaccine hesitancy. Every effort should be made to improve existing vaccines and to produce new ones, according to carefully designed scientific preclinical and clinical trials. This is particularly important in today's era, in light of the global transparency regarding vaccination development, and the potential for future pandemics such as COVID-19.

Immunization Strategies to Span the Spectrum of Immunocompromised Adults

The Advisory Committee on Immunization Practices to the US Centers for Disease Control and Prevention provides annual recommendations for routine adult immunizations. Many recommendations consider patient factors such as age, medical conditions, and medications that increase an individual's risk for infection with a vaccine-preventable disease. These factors, particularly those that lead to immunocompromise, may also alter the risk-benefit ratio for live vaccines, and/or lead to decreased vaccine immunogenicity and effectiveness. The provider may need to consider alternative vaccination strategies, including higher antigen dose vaccines, adjuvanted vaccines, avoidance of live vaccines, and careful timing of vaccination to optimize safety and effectiveness in immunocompromised populations. This thematic review discusses general principles regarding immunization of adults across the spectrum of immunocompromise, examines current guidelines and studies that support them, and outlines future research needs.