Response to Hepatitis A Vaccination in Immunocompromised Travelers

Advising the immunocompromised traveller: a review of immunocompromise at The London Hospital for Tropical Diseases Travel Clinic between 1st April 2019 and 30th April 2020

BACKGROUND

Immunocompromised travellers (ICTs) face greater infectious and non-infectious travel-associated risks than their immunocompetent counterparts. Increasing travel and emergence of novel immunosuppressants poses great challenges for travel medicine practitioners to confidently provide up-to-date evidence-based risk management advice and pre-travel care for ICTs.

METHODS

We reviewed the records of ICTs attending the London Hospital for Tropical Diseases (HTD) Travel Clinic between 1st April 2019 and 30th April 2020 with the aim to describe demographic and travel characteristics, type, and severity of immunocompromise, the degree of risk associated with intended travel and evaluate travel advice.

RESULTS

Of the 193 ICTs identified, immunocompromise was due to physiological reasons (42%), chronic infection (17.1%) and immunosuppressive therapy (16.6%). Median age was 38 (range 9 months to 84 years) and male to female ratio 0.75 (83:110). Travel was intended to 80 countries for a median of 16 days (range 2 to 3167), predominantly for leisure (53%), non-medical work (17%) and visiting friends and relatives (12%). Live vaccine safety dominated discussion in the pre-travel consultation. Existing guidelines arguably fell short in dealing with travel risks associated with hyper-specific conditions, targeted immunosuppressants and non-vaccine preventable infections.

CONCLUSIONS

Our cohort represents a wide spectrum of immunocompromise, for whom we arguably need more measurable ways to approach travel-associated risks. We propose prospective qualitative participatory research to inform our unit of the priorities of ICTs in the pre-travel consultation. We further recommend the formation of a repository of specialists and formulary of complex cases to direct subsequent informative systematic review and prospective risk studies.

Travel Medicine

International travel can cause new illness or exacerbate existing conditions. Because primary care providers are frequent sources of health advice to travelers, they should be familiar with destination-specific disease risks, be knowledgeable about travel and routine vaccines, be prepared to prescribe chemoprophylaxis and self-treatment regimens, and be aware of travel medicine resources. Primary care providers should recognize travelers who would benefit from referral to a specialized travel clinic for evaluation. Those requiring yellow fever vaccination, immunocompromised hosts, pregnant persons, persons with multiple comorbid conditions, or travelers with complex itineraries may warrant specialty referral.

Response to SARS-CoV-2 vaccination in systemic autoimmune rheumatic disease depends on immunosuppressive regimen: a matched, prospective cohort study

OBJECTIVE

To assess the humoral response to messenger RNA (mRNA) vaccine of patients with systemic autoimmune rheumatic disease (SARD) and the effect of immunosuppressive medication in a matched cohort study.

METHODS

Patients with SARD were enrolled and matched 1:1 for sex and age with healthy control (HC) subjects. Differences in humoral response to two doses of an mRNA vaccine in terms of seroconversion rate (SCR) and SARS-CoV-2 antibody level between the two groups and the impact of treatment within patients with SARD were assessed.

RESULTS

We enrolled 82 patients with SARD and 82 matched HC. SCR after the first dose was lower among the patient group than that of HC (65% compared with 100% in HC, p<0.0001) but levelled up after the second dose (94% vs 100%). After the second dose, SCR was lower for patients on combination disease-modifying antirheumatic drug (DMARD) therapy compared with all other groups (81% compared with 95% for monotherapy, p=0.01; 100% for both no DMARD therapy and HC, both p<0.0001). In addition, antibody levels after both doses were lower in patients compared with HC. We found that vaccination response was determined primarily by the number of DMARDs and/or glucocorticoids received, with patients receiving combination therapy (dual and triple therapy) showing the poorest response.

CONCLUSIONS

Patients with SARD showed a good response after the second vaccination with an mRNA vaccine. However, the choice of immunosuppressive medication has a marked effect on both SCR and overall antibody level, and the number of different immunomodulatory therapies determines vaccination response.

ImmunoStart: preparing patients for immunosuppression

Objectives

Patients with immune-mediated inflammatory disease (IMID) present an increased risk of infection. Here, we present the concept of a preventive consultation called ImmunoStart and the first results of its implementation in the care pathway of patients with IMID.

Methods

Relevant information about vaccination history, tuberculosis exposure and other infectious risks were collected through blood sampling, complete anamnesis, chest X-ray and Mantoux test. During the ImmunoStart consultation, vaccination schedules, specific treatments and risk considerations were discussed.

Results

Between October 2016 and February 2020, 437 patients were seen at an ImmunoStart consultation, mainly referred by rheumatologists (56%), dermatologists (25%) and gastroenterologists (18%). A total of 421 (96%) patients needed at least one vaccine (a mean of 3.3 vaccines per patient). Live attenuated vaccine was indicated for 45 patients (10%), requiring them to reduce or interrupt their immunosuppressive drug(s). Ninety-two patients (21%) were treated for latent tuberculosis infection.

Conclusion

This preventive consultation provides a centralized and systematic setting for the direct management of patients with IMID in need of vaccination, treatment of latent disease and specific advice regarding their immunomodulating treatments.

Vaccine serologic responses among transplant patients associate with COVID-19 infection and T peripheral helper cells

Background

Therapeutically immunosuppressed transplant recipients exhibit attenuated responses to COVID-19 vaccines. To better understand the immune alterations that determined poor vaccine response, we correlated quantities of circulating T and B cell subsets at baseline with longitudinal serologic responses to SARS-CoV-2 mRNA vaccination in heart and lung transplant recipients.

Methods

Samples at baseline and at approximately 8 and 30 days after each vaccine dose for 22 heart and lung transplant recipients with no history of COVID-19, four heart and lung transplant recipients with prior COVID-19 infection, and 12 healthy controls undergoing vaccination were analyzed. Anti-spike protein receptor binding domain (RBD) IgG and pseudovirus neutralization activity were measured. Proportions of B and T cell subsets at baseline were comprehensively quantitated.

Results

At 8-30 days post vaccination, healthy controls displayed robust anti-RBD IgG responses, whereas heart and lung transplant recipients showed minimally increased responses. A parallel absence of activity was observed in pseudovirus neutralization. In contrast, three of four (75%) transplant recipients with prior COVID-19 infection displayed robust responses at levels comparable to controls. Baseline levels of activated PD-1 ⁺ HLA-DR ⁺ CXCR5 ^- CD4 ⁺ T cells (also known as T peripheral helper [T _PH ] cells) and CD4+ T cells strongly predicted the ability to mount a response.

Conclusions

Immunosuppressed patients have defective vaccine responses but can be induced to generate neutralizing antibodies after SARS-CoV-2 infection. Strong correlations of vaccine responsiveness with baseline T _PH and CD4 ⁺ T cell numbers highlights a role for T helper activity in B cell differentiation into antibody secreting cells during vaccine response.

Immunogenicity of the Currently Recommended Pneumococcal Vaccination Schedule in Patients With Inflammatory Bowel Disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of invasive pneumococcal infections. Therefore, vaccination with the 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) 2 months later is recommended. However, the level of immunogenicity induced by this vaccination schedule in IBD patients with and without immunosuppressive medication remains unclear.

METHODS

We prospectively assessed the immunogenicity of PCV13 followed by PPSV23 in IBD patients by measuring serotype-specific pneumococcal immunoglobulin G antibody concentrations at baseline and 4-8 weeks postvaccination. Response to vaccination was defined as a postvaccination antibody concentration ≥1.3 μg/mL for 70% of the measured serotypes. We analyzed the immunogenic effect of 4 different medication regimens: (1) conventional immunomodulators (ie, oral prednisolone >10 mg/day, thiopurines, methotrexate); (2) anti-tumor necrosis factor agents; (3) combination therapy; and (4) no treatment with immunosuppressive agents (control group).

RESULTS

One hundred forty-one IBD patients were included, of whom 37 were controls. Adequate response to vaccination was 59% (61/104) in patients using immunosuppressive agents (groups 1-3) vs 81% (30/37) in controls (odds ratio, 0.33 [95% confidence interval, .13-.82]). A combination of different immunosuppressive drugs most severely impaired the immune response to pneumococcal vaccination (response, 52% [15/29]).

CONCLUSIONS

Although the sequential vaccination schedule of PCV13 followed by PPSV23 is safe, immunogenic, and thus beneficial in the majority of IBD patients, those receiving immunosuppressive agents, and especially those receiving combination therapy, have an impaired immune response compared to controls. Therefore, preferably, vaccinations should be administered before the initiation of immunosuppressive therapy.

CLINICAL TRIALS REGISTRATION

Dutch trial register #6315.

Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020

HEPATITIS A IS A VACCINE-PREVENTABLE, COMMUNICABLE DISEASE OF THE LIVER CAUSED BY THE HEPATITIS A VIRUS (HAV). THE INFECTION IS TRANSMITTED VIA THE FECAL-ORAL ROUTE, USUALLY FROM DIRECT PERSON-TO-PERSON CONTACT OR CONSUMPTION OF CONTAMINATED FOOD OR WATER. HEPATITIS A IS AN ACUTE, SELF-LIMITED DISEASE THAT DOES NOT RESULT IN CHRONIC INFECTION. HAV ANTIBODIES (IMMUNOGLOBULIN G [IGG] ANTI-HAV) PRODUCED IN RESPONSE TO HAV INFECTION PERSIST FOR LIFE AND PROTECT AGAINST REINFECTION; IGG ANTI-HAV PRODUCED AFTER VACCINATION CONFER LONG-TERM IMMUNITY. THIS REPORT SUPPLANTS AND SUMMARIZES PREVIOUSLY PUBLISHED RECOMMENDATIONS FROM THE ADVISORY COMMITTEE ON IMMUNIZATION PRACTICES (ACIP) REGARDING THE PREVENTION OF HAV INFECTION IN THE UNITED STATES. ACIP RECOMMENDS ROUTINE VACCINATION OF CHILDREN AGED 12-23 MONTHS AND CATCH-UP VACCINATION FOR CHILDREN AND ADOLESCENTS AGED 2-18 YEARS WHO HAVE NOT PREVIOUSLY RECEIVED HEPATITIS A (HEPA) VACCINE AT ANY AGE. ACIP RECOMMENDS HEPA VACCINATION FOR ADULTS AT RISK FOR HAV INFECTION OR SEVERE DISEASE FROM HAV INFECTION AND FOR ADULTS REQUESTING PROTECTION AGAINST HAV WITHOUT ACKNOWLEDGMENT OF A RISK FACTOR. THESE RECOMMENDATIONS ALSO PROVIDE GUIDANCE FOR VACCINATION BEFORE TRAVEL, FOR POSTEXPOSURE PROPHYLAXIS, IN SETTINGS PROVIDING SERVICES TO ADULTS, AND DURING OUTBREAKS.

Hepatitis A: Epidemiology, Natural History, Unusual Clinical Manifestations, and Prevention

Hepatitis A virus (HAV) is a positive-strand RNA virus that is transmitted feco-orally through person-to-person contact. Outbreaks are often linked to poor sanitation, overcrowding, or food and water contamination. Infection is often asymptomatic in children, but adults present with jaundice, abdominal pain, hepatitis, and hyperbilirubinemia. Diagnosis is through detection of immunoglobulin M antibodies against HAV, and treatment is supportive. Vaccination is the mainstay of prevention and should be given before exposure whenever possible.

Hepatitis A hospitalizations among kidney transplant recipients in the United States: nationwide inpatient sample 2005-2014

BACKGROUND

This study aimed to evaluate the hospitalization rate for Hepatitis A virus (HAV) among kidney transplant (KTx) recipients and its outcomes as well as resource utilization.

METHODS

The 2005-2014 National Inpatient Sample database was used to identify all hospitalized KTx recipients with an associated diagnosis of HAV. The hospital mortality, resource utilization, and associated liver conditions were compared between patients with and without HAV, adjusting for potential confounders.

RESULTS

Of 871 024 KTx recipients identified, 204 had HAV. The overall inpatient prevalence of HAV in KTx recipients over 10 years in the United States was 23.42 cases per 100 000 admissions. There were no statistically significant changes in the inpatient prevalence of HAV in KTx recipients during the study period (P = 0.77), ranging from 9.2 to 34.3 per 100 000 admissions. Among hospitalized KTx recipients with HAV, 27.9% were from Northeast, 29.2% were from Midwest, 23.8% were from South, and 19.1% were from West. HAV was not significantly associated with increased hospital mortality, multiorgan failure, need for abdominal ultrasound, hospital length of stay, and total hospitalization costs and charges when compared with those without HAV. However, it is significantly associated with increased ICU stay, coexisting hepatitis B and C infection, and liver failure.

CONCLUSION

Overall, inpatient prevalence of HAV in KTx recipients in the United States (years 2005-2014) was 23.42 cases per 100 000 admissions. Hospitalization for HAV after KTx is associated with increased ICU stay, coexisting hepatitis B and C infection, and liver failure.

Poor response to hepatitis A vaccination in hematopoietic stem cell transplant recipients

BACKGROUND

Hepatitis A virus (HAV) infection is highly prevalent in developing countries. In countries experiencing a shift from intermediate/high endemicity to low endemicity, the World Health Organization recommends the incorporation of HAV vaccine into the national vaccination calendar for children aged ≥1 year. Since HAV antibodies wane over time, most HSCT revaccination guidelines advise vaccination as optional, following the country recommendation. However, no study has evaluated the serological response to HAV vaccine in allogeneic HSCT recipients.

METHODS

We conducted a prospective study in 46 HSCT recipients who received two doses of inactivated HAV vaccine. Blood samples were taken before vaccination to determine HAV prevalence rates, and before and 4-6 weeks after the second dose. Specific anti-HAV antibodies were detected by a competitive commercial enzyme immune assay.

RESULTS

Patients received the first dose of vaccine at a median of 332.5 (120-4134) days after HSCT. Median absolute lymphocyte count at vaccination was 1947 (696-12 500)/mm³ . The seroprevalence rate was 93.5% at inclusion. Although safe and well tolerated, the serological response to HAV vaccine in susceptible patients was poor (33%), and no boost effect was observed in seropositive patients.

CONCLUSIONS

In areas with intermediate/high seroprevalence of HAV, serology should be recommended prior to referral to vaccination. The mechanisms of antibody interference and how to overcome T-cell function deficiency need to be better understood in transplant populations receiving HAV vaccine. Alternative schedules of HAV vaccination should be evaluated in prospective trials.

Anti-infective vaccination strategies in patients with hematologic malignancies or solid tumors-Guideline of the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO)

Infectious complications are a significant cause of morbidity and mortality in patients with malignancies specifically when receiving anticancer treatments. Prevention of infection through vaccines is an important aspect of clinical care of cancer patients. Immunocompromising effects of the underlying disease as well as of antineoplastic therapies need to be considered when devising vaccination strategies. This guideline provides clinical recommendations on vaccine use in cancer patients including autologous stem cell transplant recipients, while allogeneic stem cell transplantation is subject of a separate guideline. The document was prepared by the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO) by reviewing currently available data and applying evidence-based medicine criteria.

Vaccines for International Travel

The pretravel management of the international traveler should be based on risk management principles. Prevention strategies and medical interventions should be based on the itinerary, preexisting health factors, and behaviors that are unique to the traveler. A structured approach to the patient interaction provides a general framework for an efficient consultation. Vaccine-preventable diseases play an important role in travel-related illnesses, and their impact is not restricted to exotic diseases in developing countries. Therefore, an immunization encounter before travel is an ideal time to update all age-appropriate immunizations as well as providing protection against diseases that pose additional risk to travelers that may be delineated by their destinations or activities. This review focuses on indications for each travel-related vaccine together with a structured synthesis and graphics that show the geographic distribution of major travel-related diseases and highlight particularly high-risk destinations and behaviors. Dosing, route of administration, need for boosters, and possible accelerated regimens for vaccines administered prior to travel are presented. Different underlying illnesses and medications produce different levels of immunocompromise, and there is much unknown in this discipline. Recommendations regarding vaccination of immunocompromised travelers have less of an evidence base than for other categories of travelers. The review presents a structured synthesis of issues pertinent to considerations for 5 special populations of traveler: child traveler, pregnant traveler, severely immunocompromised traveler, HIV-infected traveler, and traveler with other chronic underlying disease including asplenia, diabetes, and chronic liver disease.

Revisiting Role of Vaccinations in Donors, Transplant Recipients, Immunocompromised Hosts, Travelers, and Household Contacts of Stem Cell Transplant Recipients

Vaccination is an effective strategy to prevent infections in immunocompromised hematopoietic stem cell transplant recipients. Pretransplant vaccination of influenza, pneumococcus, Haemophilus influenza type b, diphtheria, tetanus, and hepatitis B, both in donors and transplant recipients, produces high antibody titers in patients compared with recipient vaccination only. Because transplant recipients are immunocompromised, live vaccines should be avoided with few exceptions. Transplant recipients should get inactive vaccinations when possible to prevent infection. This includes vaccination against influenza, pneumococcus, H. influenza type b, diphtheria, tetanus, pertussis, meningococcus, measles, mumps, rubella, polio, hepatitis A, human papillomavirus, and hepatitis B. Close contacts of transplant recipients can safely get vaccinations (inactive and few live vaccines) as per their need and schedule. Transplant recipients who wish to travel may need to get vaccinated against endemic diseases that are prevalent in such areas. There is paucity of data on the role of vaccinations for patients receiving novel immunotherapy such as bispecific antibodies and chimeric antigen receptor T cells despite data on prolonged B cell depletion and higher risk of opportunistic infections.

[Traveling with immunodeficiency-Problems and prevention]

Advances in medical care have led to an increasing number of immunocompromised travellers. Travellers with immunodeficiencies have a higher risk of infections and can acquire infectious diseases that are rare in immunocompetent travellers. Of central interest are travellers' diarrhea, diseases of the respiratory tract, tuberculosis and inhalative mycoses as well as diseases transmitted by vectors such as malaria. For every such journey a timely consultation in travel medicine is indicated. First the individual risk must be assessed according to the degree of immunodeficiency. An individual counselling is then related to the itinerary, the travel destination and any activities planned. This information is the basis for an individual set of prophylactic measures with respect to infections and other risks through certain modes of behavior, medication, and vaccinations. Post-travel counselling and evaluation are equally important. This requires physicians experienced in both immunosuppression and travel medicine.

Hepatitis A vaccine immunogenicity in patients using immunosuppressive drugs: A systematic review and meta-analysis

INTRODUCTION

Inactivated hepatitis A (HepA) vaccines are very immunogenic in healthy individuals; however, it remains unclear how different immunosuppressive regimens affect HepA vaccine immunogenicity. Our objective was to summarise the current evidence on immunogenicity of HepA vaccination in patients using immunosuppressive drugs.

METHODS

We systematically searched the literature for studies on immunogenicity of inactivated HepA vaccines in adults using immunosuppressive drugs. Studies reporting seroconversion rates (SCR) 4-8 weeks after 1 and 2 doses of HepA vaccine in organ transplant recipients and patients with chronic inflammatory conditions were included in a meta-analysis.

RESULTS

We included 17 studies, comprising 1,332 individuals. In healthy controls (2 studies), SCRs were 90-94% after the first dose and 100% after the second dose. In organ transplant recipients, SCRs ranged from 0 to 67% after the first dose of vaccine and 0-97% after the second dose. In patients with chronic inflammatory conditions, SCRs ranged from 6% to 100% after the first dose and from 48 to 100% after the second dose of vaccine. Patients using a TNF-alpha inhibitor versus conventional immune-modulators (e.g. methotrexate, azathioprine, corticosteroids) were more likely to seroconvert after the first dose of vaccine (OR12.1 [2.14-68.2]) but not after the second dose of vaccine (OR 0.78 [0.21-2.92]) in a meta-analysis.

CONCLUSION

Studies evaluating HepA vaccine immunogenicity in immunosuppressive agents are heterogeneous. Overall, there is an impaired immune response following HepA vaccination in patients using immunosuppressive drugs, especially after only one dose of vaccine and in organ transplant recipients. HepA vaccination should therefore be considered before immunosuppressive therapy. Future research should focus on alternative vaccination regimens and long-term immunogenicity.

PROSPERO ID

CRD42018102607.

Vaccinations in pediatric kidney transplant recipients

Pediatric kidney transplant (KT) candidates should be fully immunized according to routine childhood schedules using age-appropriate guidelines. Unfortunately, vaccination rates in KT candidates remain suboptimal. With the exception of influenza vaccine, vaccination after transplantation should be delayed 3-6 months to maximize immunogenicity. While most vaccinations in the KT recipient are administered by primary care physicians, there are specific schedule alterations in the cases of influenza, hepatitis B, pneumococcal, and meningococcal vaccinations; consequently, these vaccines are usually administered by transplant physicians. This article will focus on those deviations from the normal vaccine schedule important in the care of pediatric KT recipients. The article will also review human papillomavirus vaccine due to its special importance in cancer prevention. Live vaccines are generally contraindicated in KT recipients. However, we present a brief review of live vaccines in organ transplant recipients, as there is evidence that certain live virus vaccines may be safe and effective in select groups. Lastly, we review vaccination of pediatric KT recipients prior to international travel.

Safe Travel Preparation for HIV-Infected Patients

PURPOSE OF REVIEW

Infectious diseases are a risk when traveling internationally, and it is important to know the potential disease burden of a region and take appropriate preventative actions before traveling. For individuals with HIV, there are special considerations and contradictions for various vaccines and medications as well as interactions with likely antiviral drugs. The purpose of this review is to summarize the vaccine and medication recommendations for travelers with HIV infection. We also review recent studies to update these recommendations.

RECENT FINDINGS

The recommendation for yellow fever vaccine has changed in June of 2016, and it is now a once in a lifetime vaccine instead of being given every 10 years. A new cholera vaccine, Vaxchora™ was approved in 2016. Since it is a live vaccine, its impact on immunocompromised individuals is still not fully known. A recent study found that immunocompromised patients responded well to the hepatitis A vaccine, although acquiring immunity may take longer than in non-immunocompromised people. There are some new anti-viral medicines that need to be considered with interactions for other travel medicines, in particular, the anti-malaria drugs. This review provides current knowledge on how HIV-infected and immunocompromised persons respond to medications and vaccines for prevention of infectious diseases in travelers. These recommendations will be useful to recommend safer travel for the HIV-infected patient. Some newer vaccines and medications will need further evaluation and assessment to determine safety and impact on HIV-positive travelers.

S. typhi Vi capsular polysaccharide vaccine-induced humoral immunity in travellers with immunosuppressive therapy for rheumatoid disease

INTRODUCTION

Typhoid fever is a global health problem, causing significant morbidity and mortality. Currently, the most widely used vaccine is the typhoid Vi capsular polysaccharide (Vi-PS) vaccine. While epidemiological studies on its efficacy have been performed in children in endemic countries, there are no efficacy studies evaluating its use in travel medicine. Response to vaccination may differ in travellers receiving immunosuppressive therapy. This study investigates the humoral response to Vi-PS vaccination in travellers receiving immunosuppressive therapy for rheumatoid disease.

METHODS

We recruited patients from the LUMC rheumatology outpatient clinic and travellers from the travel clinic who had previously received Vi-PS vaccination and also immunosuppressive therapy for rheumatoid disease. We analysed blood samples acquired from 42 patients over a period of 3 years. We estimated the length of persistence of protective titres using the survival analysis using multiple cut-off values for protection and measured titre half-life and the influence of immunosuppressive medication on titre half-life using mixed models.

RESULTS

Anti-Vi-PS antibody levels stayed above 10 EU/ml for a mean of 13.3 years, above 15 EU/ml for a mean of 10.1 years and above 20 EU/ml for a mean of 8.6 years after Vi-PS vaccination. Titre half-life was 7.5 years (95% CI 5.0-14.7 years, P < 0.001). No significant influence of medication on titre half-life was found.

CONCLUSION

Both persistence of protective antibody titres and titre half-life are longer than expected based on other studies. This warrants further study in adult volunteers, both in healthy individuals and patients suffering from rheumatoid disease.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Immunization of Solid Organ Transplant Candidates and Recipients: A 2018 Update

This article discusses the recommended vaccines used before and after solid organ transplant period, including data regarding vaccine safety and efficacy and travel-related vaccines. Vaccination is an important part of the preparation for solid organ transplantation, because vaccine-preventable diseases contribute to the morbidity and mortality of these patients. A pretransplantation protocol should be encouraged in every transplant center. The main goal of vaccination is to provide seroprotection before transplantation, because iatrogenically immunosuppressed patients posttransplant have a lower seroresponse to vaccines.

Pre-travel counseling for immunocompromised travelers: A 12-year single-center retrospective review

BACKGROUND

Immunocompromised travelers (ICTs) are medically complex and challenging for travel medicine providers. Our study hypothesizes that ICTs have high-risk travel itineraries and do not have adequate immunity against vaccine-preventable infections.

METHODS

This retrospective review of 321 ICTs from 2004 to 2015 included patients with solid organ transplant (SOT, n = 134), connective tissue disease (CTD, n = 121), inflammatory bowel disease (IBD, n = 46), and human immunodeficiency virus (HIV, n = 20). Variables included immunosuppressive medications, hepatitis A and B vaccination and serology, gamma-globulin use, and antimalarial and antidiarrheal prophylaxis. Chi-square analysis was used for categorical variables and Kruskal-Wallis for continuous variables.

RESULTS

Malaria-endemic regions accounted for 38.9% (125/321) of travel destinations. High-risk activities were planned by 37.4% (120/321) of travelers. A significant proportion of HIV patients [70.0% (14/20)] visited friends and relatives, whereas other ICTs traveled for tourism. Hepatitis A and B vaccination rates were 77.3% (248/321) and 72.3% (232/321). Post-vaccination hepatitis A and B serologic testing were completed by 66.1% (41/62) and 61.1% (11/18) of travelers, respectively.

CONCLUSION

ICTs demonstrate differences in travel patterns and risk. Serologic testing was uncommon, and vaccination rates were low. Providers should screen ICTs early for upcoming travel plans and advise vaccine completion prior to departure.

Viral infections in the biologic therapy era

INTRODUCTION

The development of biologic therapies for treating patients with rheumatic, hematologic, or oncological diseases has increased in the last few years, spreading their use in clinical practice. Areas covered: Clinical experience has evidenced substantial risks for some viral infections and/or reactivations such as viral hepatitis, herpetic infections, and other viruses, as a consequence of specific immune pathway blockages. Biological therapies produce a variable risk of reactivation of viral infections, which is particularly uncertain in the case of the most recently introduced agents. Here we make an extensive review of the viral infections associated with the use of biological drugs and provide a series of recommendations for its prevention and management. Expert commentary: To prevent these infections/reactivations, the practitioner must be aware of the infection-risk profile, performing accurate screening during and after the use of any biologic agent. In some instances, expert recommendations are made for some therapies, while in other scenarios recommendations have not yet been defined making experimental and clinical research an essential approach to elucidate multiple issues yet not resolved in this field.

The effect of immunosuppressive agents on immunogenicity of pneumococcal vaccination: A systematic review and meta-analysis

INTRODUCTION

Patients with a weakened immune system due to immunosuppressive treatment are at increased risk of infection with Streptococcus pneumoniae. Although pneumococcal vaccination is highly recommended for those patients, the effectiveness of pneumococcal vaccination in this population remains largely unknown. Therefore, the objective of this PROSPERO-registered systematic review and meta-analysis was to evaluate the effect of the most commonly prescribed immunosuppressive agents such as azathioprine, methotrexate, anti-Tumor Necrosis Factor α (TNFα), or rituximab, on the initial serologic response to pneumococcal vaccination in patients with auto-immune disease.

METHODS

We included 22 articles comprising 2077 patients, of whom 1623 were treated with immunosuppressive agents, and 454 were controls.

RESULTS AND DISCUSSION

The findings of our systematic review indicate that, in patients treated with immunosuppressive medication and compared to controls, the initial serologic response to pneumococcal conjugate vaccine (PCV) and pneumococcal polysaccharide vaccine (PPSV) are impaired. Moreover, this impaired response was more profound after PCV than after PPSV. We hypothesize that the immunosuppressive medication mainly compromises the cellular immunity, explaining the more severely reduced response rate to PCV (which induces a T-cell dependent immune response), compared to PPSV. Treatment with TNFα blocking agents was associated with a more favorable response, compared to patients treated with other immunosuppressive medication. Targeted research applying uniform correlates of protection is needed to bridge the knowledge gap in vaccination immunology in this patient group. PROSPERO registration: CRD42017058364.

Serologic responses and effectiveness of hepatitis A vaccination among human immunodeficiency virus-positive individuals during the outbreak of acute hepatitis A

Outbreaks of hepatitis A virus (HAV) infection have been occurring among men who have sex with men in the Asia-Pacific region, the United States, and several European countries since June 2015 and recently among persons who are homeless and use illicit drugs in the United States. We evaluated the serologic responses and effectiveness of HAV vaccination in human immunodeficiency virus (HIV)-positive individuals during the outbreak in Taiwan. From June 1, 2015, to September 30, 2016, anti-HAV immunoglobulin G was prospectively determined among all HIV-positive individuals. We prospectively observed 1,533 HAV-seronegative, HIV-positive individuals (94.1% being men who have sex with men with a median cluster of differentiation 4 (CD4) count of 550 cells/μL) who were advised to receive two doses of HAV vaccine administered 6 months apart. Of them, 1,001 individuals (65.3%) received at least one dose of HAV vaccine during the study period and 532 (34.7%) declined to receive vaccine. The primary endpoints were serologic response at weeks 28-36 and acquisition of HAV infection during follow-up. The incidence rate of acute HAV infection was 3.7 and 99.3 per 1,000 person-years of follow-up in the vaccinated and unvaccinated groups, respectively, resulting in a vaccine effectiveness of 96.3%. At weeks 28-36, the seroconversion rates were 63.8% and 93.7% in the intention-to-treat and per-protocol analyses, respectively. The factors associated with seroconversion at weeks 28-36 were younger age (per 1-year decrease, adjusted odds ratio, 1.08; 95% confidence interval, 1.02-1.12) and undetectable plasma HIV RNA load (adjusted odds ratio, 3.19; 95% confidence interval, 1.32-7.68).

CONCLUSION

During the outbreak of acute hepatitis A, two-dose HAV vaccination is effective at preventing HAV infection among HIV-positive individuals receiving combination antiretroviral therapy; our data highlight the importance of HAV serologic screening and vaccination to prevent outbreaks of acute hepatitis A in at-risk populations. (Hepatology 2018;68:22-31).

An extra priming dose of hepatitis A vaccine to adult patients with rheumatoid arthritis and drug induced immunosuppression - A prospective, open-label, multi-center study

BACKGROUND

Previous studies have indicated that a pre-travel single dose of hepatitis A vaccine is not sufficient as protection against hepatitis A in immunocompromised travelers. We evaluated if an extra dose of hepatitis A vaccine given shortly prior to traveling ensures seroconversion.

METHOD

Patients with rheumatoid arthritis (n = 69, median age = 55 years) treated with Tumor Necrosis Factor inhibitor(TNFi) and/or Methotrexate (MTX) were immunized with two doses of hepatitis A vaccine, either as double dose or four weeks apart, followed by a booster dose at six months. Furthermore, 48 healthy individuals, median age = 60 years were immunized with two doses, six months apart. Anti-hepatitis A antibodies were measured at 0, 1, 2, 6, 7 and 12 months.

RESULTS

Two months after the initial vaccination, 88% of the RA patients had protective antibodies, compared to 85% of the healthy individuals. There was no significant difference between the two vaccine schedules. At twelve months, 99% of RA patients and 100% of healthy individuals had seroprotective antibodies.

CONCLUSION

An extra priming dos of hepatitis A vaccine prior to traveling offered an acceptable protection in individuals treated with TNFi and/or MTX. This constitutes an attractive pre-travel solution to this vulnerable group of patients.

International travelers receiving pharmacological immunosuppression: Challenges and opportunities

There is an increasing number of international travelers receiving immunosuppressive therapy due to the better life expectation and quality offered by this kind of treatment. The complexity of pre-travel counseling in these patients lies in their greater susceptibility to certain travel-related infections and the potential severity of these, as well as in the contraindications and interactions that may occur between certain vaccines and/or prophylaxis and their base therapy. Counseling the traveler represents a challenge for clinicians who have to tailor vaccinations and other recommended preventive measures to the immunosuppressed patients. Thus, pre-travel assessment of patients receiving immunosuppressive therapy should be performed in a specialized Traveler's Medical Unit, working closely with the specialist doctor in charge of treating the patient's underlying medical condition. The purpose of this article is to review available evidence on the health recommendations indicated in the pre-travel administration of vaccines, antimalarial chemoprophylaxis and other measures to prevent communicable diseases in travelers receiving immunosuppressive therapy.

Pre-travel care for immunocompromised and chronically ill travellers: A retrospective study

BACKGROUND

Immunocompromised and chronically ill travellers (ICCITs) are susceptible to travel related diseases. In ICCITs, pre-travel care regarding vaccinations and prophylactics is complex. We evaluated the protection level by preventive measures in ICCITs by analysing rates of vaccination protection, antibody titres, and the prescription of standby antibiotics.

METHODS

We analysed, and reported according to STROBE guidelines, pre-travel care data for ICCITs visiting the medical pre-travel clinic at the Academic Medical Centre, The Netherlands from 2011 to 2016.

RESULTS

We analysed 2104 visits of 1826 ICCITs. Mean age was 46.6 years and mean travel duration 34.5 days. ICCITs on immunosuppressive treatment (29.7%), HIV (17.2%) or diabetes mellitus (10.2%) comprised the largest groups. Most frequently visited countries were Suriname, Indonesia, and Ghana. Most vaccination rates were >90%. Of travellers in high need of hepatitis A and B protection, 56.6 and 75.7%, underwent titre assessments, respectively. Of ICCITs with a respective indication, 50.6% received a prescription for standby antibiotics.

CONCLUSION

Vaccination rates in our study population were overall comparable to those of healthy travellers studied previously in our centre. However, regarding antibody titre assessments and prescription of standby antibiotics, this study demonstrates that uniform pre-travel guidelines for ICCITs are highly needed.

Closing the gap in travel medicine: reframing research questions for a new era

BACKGROUND

Travel medicine needs are changing. New patterns of travel, including greater travel by individuals from emerging economies with different values in costs, risks and benefits, must be considered. This review aims to (1) highlight selected studies that have been published that address previously identified gaps in knowledge; (2) propose possible ways to consider questions regarding travel medicine practice for travelers from emerging economies, underscoring priorities for research focusing on these important populations; (3) highlight potential deficiencies in relevance of current international guidelines as they pertain to travelers from emerging economies; (4) frame research questions for travelers from emerging economies and (5) consider roles for ISTM in closing the gap.

METHODS

We reviewed past travel medicine research priorities published in 2010 to identify publications that responded to some research questions posed. We also reviewed CDC and WHO recommendations and assessed their applicability to travelers from emerging economies.

RESULTS

Recent publications have responded to some research questions, but gaps remain and new questions have emerged. Re-framing of several key research questions is needed for travelers from emerging economies.

DISCUSSION

A new challenge looms for traditional travel medicine fields to identify and attend to knowledge and guideline gaps, particularly to rethink questions regarding travel medicine to make them relevant for travelers from emerging economies. The International Society of Travel Medicine is well positioned to assist emerging economies assess their resources and needs, formulate research priorities and tailor the development of travel medicine into a framework aligned to their requirements.

Approach to Immunization for the Traveling Child

Children are traveling to regions of the world that could pose a risk of acquiring diseases such as malaria, dermatosis, and infectious diarrhea. Most of these can be prevented by modifying high-risk behaviors or through the use of medications. Many of these same regions are endemic with diseases that are preventable through vaccination. Clinicians must be able to effectively prepare their pediatric-age travelers for international travel. Preventive education, prophylactic and self-treating medications, and vaccinations are all important components of this preparation. Familiarity with the use of travel vaccines is imperative.

Infectious diseases in allogeneic haematopoietic stem cell transplantation: prevention and prophylaxis strategy guidelines 2016

Infectious complications after allogeneic haematopoietic stem cell transplantation (allo-HCT) remain a clinical challenge. This is a guideline provided by the AGIHO (Infectious Diseases Working Group) of the DGHO (German Society for Hematology and Medical Oncology). A core group of experts prepared a preliminary guideline, which was discussed, reviewed, and approved by the entire working group. The guideline provides clinical recommendations for the preventive management including prophylactic treatment of viral, bacterial, parasitic, and fungal diseases. The guideline focuses on antimicrobial agents but includes recommendations on the use of vaccinations. This is the updated version of the AGHIO guideline in the field of allogeneic haematopoietic stem cell transplantation utilizing methods according to evidence-based medicine criteria.

Travel vaccination recommendations and endemic infection risks in solid organ transplantation recipients

BACKGROUND

Solid organ transplant (SOT) recipients are often heavily immunosuppressed and consequently at risk of serious illness from vaccine preventable viral and bacterial infections or with endemic fungal and parasitic infections. We review the literature to provide guidance regarding the timing and appropriateness of vaccination and pathogen avoidance related to the immunological status of SOT recipients.

METHODS

A PUBMED search ([Vaccination OR vaccine] AND/OR ["specific vaccine"] AND/OR [immunology OR immune response OR cytokine OR T lymphocyte] AND transplant was performed. A review of the literature was performed in order to develop recommendations on vaccination for SOT recipients travelling to high-risk destinations.

RESULTS

Whilst immunological failure of vaccination in SOT is primarily the result of impaired B-cell responses, the role of T-cells in vaccine failure and success remains unknown. Vaccination should be initiated at least 4 weeks prior to SOT or more than 6 months post-SOT. Avoidance of live vaccination is generally recommended, although some live vaccines may be considered in the specific situations (e.g. yellow fever). The practicing physician requires a detailed understanding of region-specific endemic pathogen risks.

CONCLUSIONS

We provide a vaccination and endemic pathogen guide for physicians and travel clinics involved in the care of SOT recipients. In addition, recommendations based on timing of anticipated immunological recovery and available evidence regarding vaccine immunogenicity in SOT recipients are provided to help guide pre-travel consultations.

Enquiries to the United Kingdom National Travel Advice Line by healthcare professionals regarding immunocompromised travellers

BACKGROUND

People who travel while immunocompromised are more at risk of serious travel-related infection. Their condition, medications or treatments can contraindicate, decrease the effectiveness of or increase the toxicity of vaccinations or malaria chemoprophylaxis. Therefore, immunocompromised travellers require careful assessment and specialized pre-travel advice. The aims of this study were to investigate enquiries by healthcare professionals (HCPs) to the UK National Travel Health Network and Centre (NaTHNaC) advice line regarding travellers with immunocompromise and to identify their most common concerns.

METHODS

Documentation for all calls taken by advisers at the London office during 2013 was reviewed.

RESULTS

Of the 4910 enquiries to the London NaTHNaC advice line, 397 calls concerned immunocompromised travellers (8.1%). The majority of immunocompromised travellers were planning to visit Sub-Saharan Africa (53%) for the purpose of tourism (43%). Sixty-seven percent of enquiries concerned vaccine use, 11% were about malaria chemoprophylaxis, 20% were about both and 2% were for other reasons. Causes of immunocompromise included inflammatory or autoimmune conditions (43%), cancer (18%), splenic dysfunction (13%), immunosuppressive drugs (12%), human immunodeficiency virus (11%), primary immunodeficiency (1%), neutropenia (0.5%) and thymus abnormalities (0.5%).

CONCLUSIONS

There were frequent enquires to the advice line by UK HCPs regarding immunocompromised travellers. The travellers in this study had a wide range of underlying medical conditions and varying levels of immunocompromise. These enquiries may reflect a lack of clarity in current national guidelines, difficulties in interpreting them or both. Establishing the reasons for these deficiencies as well as the reasons behind UK HCP concerns and lack of confidence requires further investigation. This research has highlighted potential knowledge gaps and will help inform future guidance and educational activities for UK HCPs advising travellers.