Assessing the immunological response to hepatitis B vaccination in HIV-infected patients in clinical practice

Immune response to mRNA-based COVID-19 booster vaccination in people living with HIV

OBJECTIVES

Our objective was to assess immune responses and their influencing factors in people living with HIV after messenger RNA (mRNA)-based COVID-19 booster vaccination (third dose).

METHODS

This was a retrospective cohort study of people living with HIV who received booster vaccination with BNT-162b2 or mRNA-1273 between October 2021 and January 2022. We assessed anti-spike receptor-binding domain (RBD) immunoglobulin G (IgG), virus neutralizing activity (VNA) titres reported as 100% inhibitory dilution (ID₁₀₀ ), and T-cell response (using interferon-gamma-release-assay [IGRA]) at baseline and quarterly follow-up visits. Patients with reported COVID-19 during follow-up were excluded. Predictors of serological immune response were analyzed using multivariate regression models.

RESULTS

Of 84 people living with HIV who received an mRNA-based booster vaccination, 76 were eligible for analysis. Participants were on effective antiretroviral therapy (ART) and had a median of 670 CD4⁺ cells/μL (interquartile range [IQR] 540-850). Following booster vaccination, median anti-spike RBD IgG increased by 705.2 binding antibody units per millilitre (BAU/mL) and median VNA titres increased by 1000 ID₁₀₀ at the follow-up assessment (median 13 weeks later). Multivariate regression revealed that time since second vaccination was a predictor of stronger serological responses (p < 0.0001). No association was found for other factors, including CD4⁺ status, choice of mRNA vaccine, or concomitant influenza vaccination. In total, 45 patients (59%) had a reactive baseline IGRA, of whom two lost reactivity during follow-up. Of 31 patients (41%) with non-reactive baseline IGRA, 17 (55%) converted to reactive and seven (23%) remained unchanged following booster vaccination.

CONCLUSIONS

People living with HIV with ≥500 CD4⁺ cells/μL showed favourable immune responses to mRNA-based COVID-19 booster vaccination. A longer time (up to 29 weeks) since second vaccination was associated with higher serological responses, whereas choice of mRNA vaccine or concomitant influenza vaccination had no impact.

Assessing the cost-utility of preferentially administering Heplisav-B vaccine to certain populations

Vaccination is the primary strategy to prevent hepatitis B virus (HBV) infection in the United States. Prior to 2017, most standard hepatitis B vaccine schedules required 3 doses over 6 months. Heplisav-B, approved in 2017, is administered in 2 doses over a 1 month time period but has a higher per-dose cost ($115.75 per dose compared to $57.25 per Engerix-B dose, costs as of June 1, 2019). We aimed to assess the cost-utility of providing the two-dose Heplisav-B vaccine compared to a three-dose Engerix-B vaccine among adult populations currently recommended for vaccination against hepatitis B. We used a decision-tree model with microsimulation and a Markov disease progression process to assess the cost-utility separately for the following populations: adults with diabetes, obesity, chronic kidney disease, HIV; non-responders to previous hepatitis B vaccination; older adults; and persons who inject drugs (PWID). We modeled epidemiologic outcomes (incident HBV infections, sequelae and related deaths), costs (2019 USD) and benefits (quality-adjusted life years, QALYs) and compared them across strategies. Sensitivity analyses assessed the cost-utility at varying estimates of Heplisav-B efficacy. In the base case scenario for each population, vaccination with Heplisav-B resulted in fewer HBV infections (37.5-59.8% averted), sequelae, and HBV-related deaths (36.3-71.4% averted). Heplisav-B resulted in decreased costs and increased benefits compared to Engerix-B for all populations except non-responders. Incremental costs from the baseline strategy ranged from $4746.78 saved (PWID) to $14.15 added cost (non-responders). Incremental benefits per person ranged from 0.00005 QALYs (older adults) to 0.7 QALYs (PWID). For persons with HIV and PWID, Heplisav-B resulted in lower costs and increased benefits in all scenarios in which Heplisav-B series efficacy was at least 80%. Vaccination using Heplisav-B is a cost-saving strategy compared to Engerix-B for adults with diabetes, chronic kidney disease, obesity, and HIV; older adults; and PWID.

Telomere and ATM Dynamics in CD4 T-Cell Depletion in Active and Virus-Suppressed HIV Infections

CD4 T-cell depletion is a hallmark of HIV/AIDS, but the underlying mechanism is still unclear. We have recently shown that ataxia-telangiectasia-mutated (ATM) deficiency in CD4 T cells accelerates DNA damage, telomere erosion, and cell apoptosis in HIV-infected individuals on antiretroviral therapy (ART). Whether these alterations in ART-treated HIV subjects occur in vitro in HIV-infected CD4 T cells remains unknown. In this study, we employed a cellular model of HIV infection to characterize the mechanisms underlying CD4 T-cell destruction by analyzing the telomeric DNA damage response (DDR) and cellular apoptosis in highly permissive SupT1 cells, followed by the validation of our observations in primary CD4 T cells with active or drug-suppressed HIV infection. Specifically, we established an in vitro HIV T-cell culture system with viral replication and raltegravir (RAL; an integrase inhibitor) suppression, mimicking active and ART-controlled HIV infection in vivo We demonstrated that HIV-induced, telomeric DDR plays a pivotal role in triggering telomere erosion, premature T-cell aging, and CD4 T-cell apoptosis or depletion via dysregulation of the PI3K/ATM pathways. This in vitro model provides a new tool to investigate HIV pathogenesis, and our results shed new light on the molecular mechanisms of telomeric DDR and CD4 T-cell homeostasis during HIV infection.IMPORTANCE The hallmark of HIV infection is a gradual depletion of CD4 T cells, with a progressive decline of host immunity. How CD4 T cells are depleted in individuals with active and virus-suppressed HIV infection remains unclear. In this study, we employed a cellular model of HIV infection to characterize the mechanisms underlying CD4 T-cell destruction by analyzing the chromosome end (telomere) DNA damage response (DDR) and cellular apoptosis in a T-cell line (highly permissive SupT1 cells), as well as in primary CD4 T cells with active or drug-suppressed HIV infection. We demonstrated that HIV-induced telomeric DDR plays a critical role in inducing telomere loss, premature cell aging, and CD4 T-cell apoptosis or depletion via dysregulation of the PI3K/ATM pathways. This study sheds new light on the molecular mechanisms of telomeric DDR and its role in CD4 T-cell homeostasis during HIV infection.

Evaluation of response to hepatitis B virus vaccine in adults with human immunodeficiency virus

INTRODUCTION AND AIM

Viral hepatitis is a serious public health problem. The risk of progression to chronic hepatitis in hepatitis B virus (HBV) infection occurs in 5-10% of adults and is a leading cause of cirrhosis and hepatocellular carcinoma worldwide. Individuals infected with human immunodeficiency virus (HIV) may have coinfection with HBV. The existence of unvaccinated groups represents a significant risk not only individually but also at the community level. The aim of this study was to evaluate HBV vaccine response in adults with HIV infection.

MATERIALS AND METHODS

A retrospective, descriptive study of the cross-sectional type was carried out in an outpatient HIV referral center in southern Brazil. All medical records of adult HIV patients seen during January 2006 to December 2015 were selected. In statistical analysis, a significance level of 5% was used.

RESULTS

Of the 201 patients evaluated with a complete vaccination scheme, 55.72% were males, with a mean age of 43.86±12.68 years. Vaccine response occurred in 80.10% (161/201) of the patients, and it did not correlate with age, CD4+ cell count or viral load.

CONCLUSION

HBV vaccine response in a HIV population was satisfactory, highlighting the importance of vaccination for prevention, cost reduction and better prognosis in preventing HBV/HIV coinfection.

Hepatitis B Vaccination and Waning Hepatitis B Immunity in Persons Living with HIV

PURPOSE OF REVIEW

Persons with HIV are at a higher risk for acquiring HBV (hepatitis B virus) than the general population due to shared modes of transmission and are significantly more likely to develop and die from sequelae of chronic HBV infection. Early vaccination is key to achieving HBV protective immunity, but response rates are still much lower than in the general population, ranging from 35 to 70%. Individuals with HIV also experience more rapidly waning immunity than those without HIV. Strategies to augment initial response and improve long-term immunity in individuals with HIV include alterations in dose, frequency, and the use of immune adjuvants.

RECENT FINDINGS

Recent studies have focused on the use of different vaccine formulations, the use of vaccine adjuvants, increased number and strength of vaccine dosages, increased dose frequency, alternative routes of administration, dual vaccinations, and the use of booster vaccines. Although no consensus has been reached on the use of certain vaccination regimens, three and four double-dose vaccine schedules via the intramuscular route have demonstrated higher initial response rates. Early vaccination when CD4 cell counts are greater than 350/mm³ with low viral loads has been shown to improve initial response, along with completion of immunization series. Adjuvants such as TLR4 and TLR9 agonists appear to improve response to HBV vaccination, but further research is needed in individuals with HIV. Persons with HIV have significant lower initial and long-term seroresponse rates after HBV vaccination than immunocompetent individuals. Recent and ongoing studies continue to evaluate multiple strategies to improve these rates within a uniquely susceptible population.

Inflammasome in HIV infection: Lights and shadows

The importance of inflammasome, and related cytokines IL-1ß and IL-18, in host defense against pathogens is well documented, however, at the same time, dysregulation of inflammasome has been associated to multifactorial diseases characterized by chronic inflammation (i.e.: metabolic disorders, cardiovascular diseases, neurodegenerative diseases, autoimmunity, cancer). Inflammasome activation has been described in response to HIV-1 and possibly contributes to the resistance against virus establishment, however, on the other hand, when viral infection becomes chronic, independently from antiretroviral therapy, the increase constitutive activation of inflammasome has been eventually associated to a worse prognosis, raising the question about the role played by inflammasome and/or some specific receptors in this context. Due to the chance to imply targeted therapies that inhibit inflammasome activation and/or cytokines release, it will be important to define the impact of the complex in the pathogenesis of HIV. The purpose of this review is to depict the double-faced inflammasome role in HIV-1 infection, trying to unveil whether besides its role in first line defense against the virus, it exerts a harmful effect during the chronic phase of infection.

Comparison of Safety and Vector-Specific Immune Responses in Healthy and HIV-Infected Populations Vaccinated with MVA-B

There are few studies comparing the safety and immunogenicity of the same HIV immunogen in healthy volunteers and HIV-infected individuals. We analyzed demographics, adverse events (AEs), and immunogenicity against vaccinia virus in preventive (RISVAC02, n = 24 low-risk HIV-negative volunteers) and therapeutic (RISVAC03, n = 20 successfully treated chronically HIV-1-infected individuals) vaccine phase-I clinical trials that were performed with the same design and the same immunogen (modified vaccinia virus Ankara-B: MVA-B). Total AEs were significantly higher in HIV-infected patients (mean AEs/patient 6.6 vs. 12.8 (p < 0.01)). Conversely, the number of AEs related to vaccination (AEsRV) was similar between both groups. No grade III or IV AEsRV were observed in either clinical trial. Regarding the immunogenicity, the proportion of anti-vaccinia virus antibody responders was similar in both studies. Conversely, the magnitude of response was significantly higher in HIV-infected patients (median binding antibodies at w8 267 vs. 1600 U/mL (p = 0.002) and at w18 666 vs. 3200 U/mL (p = 0.003)). There was also a trend towards higher anti-vaccinia virus neutralizing activity in HIV-infected individuals (proportion of responders 37% vs. 63% (p = 0.09); median IC50 32 vs. 64 (p = 0.054)). This study confirms the safety of MVA-B independent of HIV serostatus. HIV-infected patients showed higher immune responses against vaccinia virus.

ATM Deficiency Accelerates DNA Damage, Telomere Erosion, and Premature T Cell Aging in HIV-Infected Individuals on Antiretroviral Therapy

HIV infection leads to a phenomenon of inflammaging, in which chronic inflammation induces an immune aged phenotype, even in individuals on combined antiretroviral therapy (cART) with undetectable viremia. In this study, we investigated T cell homeostasis and telomeric DNA damage and repair machineries in cART-controlled HIV patients at risk for inflammaging. We found a significant depletion of CD4 T cells, which was inversely correlated with the cell apoptosis in virus-suppressed HIV subjects compared to age-matched healthy subjects (HS). In addition, HIV CD4 T cells were prone to DNA damage that extended to chromosome ends-telomeres, leading to accelerated telomere erosion-a hallmark of cell senescence. Mechanistically, the DNA double-strand break (DSB) sensors MRE11, RAD50, and NBS1 (MRN complex) remained intact, but both expression and activity of the DNA damage checkpoint kinase ataxia-telangiectasia mutated (ATM) and its downstream checkpoint kinase 2 (CHK2) were significantly suppressed in HIV CD4 T cells. Consistently, ATM/CHK2 activation, DNA repair, and cellular functions were also impaired in healthy CD4 T cells following ATM knockdown or exposure to the ATM inhibitor KU60019 in vitro, recapitulating the biological effects observed in HIV-derived CD4 T cells in vivo. Importantly, ectopic expression of ATM was essential and sufficient to reduce the DNA damage, apoptosis, and cellular dysfunction in HIV-derived CD4 T cells. These results demonstrate that failure of DSB repair due to ATM deficiency leads to increased DNA damage and renders CD4 T cells prone to senescence and apoptotic death, contributing to CD4 T cell depletion or dysfunction in cART-controlled, latent HIV infection.

Response to a reinforced hepatitis B vaccination scheme in HIV-infected patients under real-life conditions

BACKGROUND

HIV-infected patients are at risk of hepatitis B virus (HBV) coinfection, however, respond worse to HBV vaccination (HBV-V) than immunocompetent adults. This study aimed to determine the response to reinforced HBV-V in HIV-infected subjects under real-life conditions.

METHODS

HIV-infected patients followed at a Spanish University Hospital who were seronegative for HBV and who received three double-doses (40 µL) of HBV-V at 0, 1 and 2 months were included. Response to HBV-V was defined as HBV surface antibody concentration of ≥10 IU/L 1-12 months after the last HBV-V dose.

RESULTS

Of 332 patients included in the study, 256 (77.1%) showed response to HBV-V. Median (interquartile range) CD4⁺/CD8⁺ ratio among the responders was 0.75 (0.52-1.01) versus 0.61 (0.38-0.84) among the non-responders (p = 0.002). Independent predictors for HBV-V response were: female gender [adjusted odds ratio (AOR): 6.240; 95% confidence interval (95%CI): 1.954-19.925; p = 0.002]; non-smoking [AOR: 2.151; 95%CI: 1.243-3.721; p = 0.006]; a CD4⁺/CD8⁺ ratio ≥0.67 [AOR: 2.580; 95%CI: 1.209-5.505; p = 0.014] and baseline HIV-RNA ≤50 copies/mL [AOR: 2.049; 95%CI: 1.098-3.824; p = 0.024].

CONCLUSION

Accelerated administration of three double-doses results in considerable high, however still suboptimal, response rates to HBV-V in HIV-infected patients in the clinical practice. A fourth dose should be considered.

Immune response to hepatitis A vaccine in patients with HIV

OBJECTIVES

The aim of this study was to evaluate the impact of various factors that may influence the immunologic response to hepatitis A mono-vaccine or hepatitis A/B co-vaccine (Twinrix®) in HIV-infected patients.

DESIGN

Retrospective cross-sectional study.

METHODS

HIV positive patients with a full course of hepatitis A vaccine were tested for HAV antibodies. The seroconversion rates were determined, and the influence of several factors including CD4 cell counts, CD4/CD8 ratio, plasma viral load, type of vaccine, and antiretroviral therapy at the time of vaccine, was evaluated.

RESULTS

After vaccination, 80.2% of the patients developed anti-HAV antibodies, 81.5% in the mono-vaccine group and 79.2% in the hepatitis A/B co-vaccine group. In the mono-vaccine group, factors significantly associated with a better response to the vaccine were higher CD4 cell count, higher CD4/CD8 ratio, and shorter time interval from vaccine to serological control. In patients who received the hepatitis A/B co-vaccine, younger age and female sex were significantly associated with better vaccine response. Multivariable logistic regression analysis revealed time interval from vaccine to serological control of more than 5 years vs. less than 1 year to be significantly associated with decrease of seroconversion after HAV vaccine.

CONCLUSIONS

The response to hepatitis A vaccine is impaired in HIV positive patients. HIV patients, at least those older than 30, should be tested for seroconversion after receiving the hepatitis A vaccine. As hepatitis A titers may rapidly decline, control serology during follow-up should be proposed, possibly within two years. However, vaccine type does not play a role in vaccine response.

Long-term protection after hepatitis B vaccination in people living with HIV

BACKGROUND

Hepatitis B vaccine is important in people living with HIV (PLHIV) since both viruses have the same transmission routes and co-infection has greater morbidity. PLHIV usually have poor response to hepatitis B vaccine. The duration of immunity in PLHIV is unknown. The objective of this study is to evaluate the duration of serological response and clinical protection provided by hepatitis B vaccination in PLHIV.

METHODS

Retrospective study of a PLHIV cohort primarily vaccinated for hepatitis B virus (HBV) from 2001 to 2002. Markers of infection and protection from HBV were investigated in those individuals who were still attending the outpatient clinic, in São Paulo, Brazil from 2012 to 2014. Three groups were analyzed. Group 1: adults who responded to primary vaccine series. Group 2: non-responders to primary vaccine series. Group 3: subjects from both Groups 1 and 2 who did not receive any booster doses after seroconversion.

RESULTS

A cohort of 121 PLHIV was analyzed for seroconversion and persistence of anti-HBs. The majority were female (54.5%) and mean age was 50.1years. After 11years, none of the patients had serologic evidence of HBV infection. Overall, 41/58 (70.7%) of the initial responders (Group 1) had maintained anti-HBs≥10mIU/mL. Greater CD4+ values and anti-HBs>100mIU/mL at the time of first vaccine series were associated with persistence of anti-HBs. During the time of evaluation, 35/63 (55.6%) of the initial non-responders (Group 2) successfully seroconverted (anti-HBs≥10mIU/mL) in response to one or more booster doses. From the time of their seroconversion, 70 of the patients did not receive any further booster doses (Group 3). After 10years, 54/70 (77.1%) of these individuals has maintained anti-HBs≥10mIU/mL.

CONCLUSIONS

Evaluation of long-term immunity for hepatitis B in PLHIV following vaccination showed a strong persistence of anti-HBs and no serologic evidence of HBV infection. Boosters may be effective in PLHIV non-responders to primary vaccination.

Hepatitis B virus vaccination in HIV-infected people: A review

HBV immunization is highly recommended in people infected with HIV. However, the classical schedule used in the general population has been shown to be insufficient in people living with HIV. This review summarizes the main studies dealing with HBV vaccination in people living with HIV, depending on their baseline status (in particular, never vaccinated, already vaccinated, or with an isolated anti-HBc serological profile). It shows that reinforced 40µg intramuscular HBV vaccination schedules are now frequently recommended, either initially in people never vaccinated, or in the lack of an anamnestic response in other situations. Adjuvants cannot be currently recommended. Anti-HBs titers have to be checked 1 to 2 months following the last vaccine dose, and annually thereafter a booster is necessary if antiHBs titers decrease below 10 mIU/mL. In patients with a CD4 cell count <200/µL, guidelines recommend starting the vaccination regimen as soon as possible after HAART has been started.

Immunization of HIV-infected adult patients - French recommendations

Human immunodeficiency virus (HIV)-infected patients remain at increased risk of infection including vaccine-preventable diseases. Vaccines are therefore critical components in the protection of HIV-infected patients from an increasing number of preventable diseases. However, missed opportunities for vaccination among HIV-infected patients persist and vaccine coverage in this population could be improved. This article presents the French recommendations regarding immunization of HIV-infected adults in the light of the evidence-based literature on the benefits and the potential risks of vaccines among this vulnerable population.

A Randomized Study Comparing the Efficacy of Three Hepatitis B Vaccine Induction Regimens in Adult Patients with Hematological Malignancies

Objective:

Non-responsiveness to hepatitis B virus (HBV) vaccines is not rare in hemato-oncological patients due to disease-associated or treatment-induced immune suppression. Although different strategies have been employed to improve the response rates, to date there is not an approved schedule for HBV immunization in patients with hematological malignancies. We designed a prospective randomized study to evaluate the efficacy of 3 different induction regimens for HBV vaccination.

Materials and Methods:

In the standard-dose (SD) group, total vaccine dose delivered was 40 µg and patients were vaccinated with 20 µg at weeks 0 and 4. In the high-dose dose-intensive (HDDI) group, total vaccine dose delivered was 80 µg and patients were vaccinated with 40 µg at weeks 0 and 4. In the high-dose time-intensive (HDTI) group, total vaccine dose delivered was 80 µg and patients were vaccinated with 20 µg at weeks 0, 2, 4, and 6.

Results:

In a cohort of 114 patients, 38.6% responded to HBV vaccination. The response rate in the SD arm, HDDI arm, and HDTI arm was 26.2%, 29.7%, and 44.4%, respectively (p>0.05). Age was the only variable identified as having a negative impact on response.

Conclusion:

Short of achieving statistical significance, a higher response rate was observed in the HDTI arm. Therefore, this study supports a high-dose, time-intensive HBV vaccine induction regimen in patients with hematological malignancies who are not on chemotherapy.

Hepatitis B and A vaccination in HIV-infected adults: A review

Hepatitis B and A account for considerable morbidity and mortality worldwide. Immunization is the most effective means of preventing hepatitis B and A. However, the immune response to both hepatitis vaccines seems to be reduced in HIV-infected subjects. The aim of this review was to analyze the immunogenicity, safety, long-term protection and current recommendations of hepatitis B and A vaccination among HIV-infected adults. The factors most frequently associated with a deficient level of anti-HBs or IgG anti-HAV after vaccination are those related to immunosuppression (CD4 level and HIV RNA viral load) and to the frequency of administration and/or the amount of antigenic load per dose. The duration of the response to both HBV and HAV vaccines is associated with suppression of the viral load at vaccination and, in the case of HBV vaccination, with a higher level of antibodies after vaccination. In terms of safety, there is no evidence of more, or different, adverse effects compared with HIV-free individuals. Despite literature-based advice on the administration of alternative schedules, revaccination after the failure of primary vaccination, and the need for periodic re-evaluation of antibody levels, few firm recommendations are found in the leading guidelines.

Hepatitis B revaccination in HIV-infected vaccine non-responders: is double dosing always necessary?

Limited data exist on hepatitis B revaccination strategies for HIV-infected individuals who do not develop immunity after the first vaccination series. A retrospective cohort study was conducted to assess the immunogenicity of the second series of hepatitis B vaccine given in standard dosing (SD) and double dosing (DD) strategies among Thai HIV-infected adults during the period from January 2006 to December 2014. Of the 120 eligible patients, 68 (57%) were men, median age was 38 years old, 87 (73%) received SD and 33 (27%) received DD revaccination. The demographic and clinical characteristics of SD and DD groups were comparable. The overall vaccine response rate was significantly higher in DD group than SD group (97% vs. 70%; p = 0.001). Independent factors associated with no response to hepatitis B revaccination were receipt of SD vaccine (adjusted odds ratio [aOR] 16.04; p = 0.009), age ≥ 40 years (aOR 3.66; p = 0.009) and CD4 cell count at the time of revaccination less than 450 cells/µL (aOR 2.96; p = 0.04). These findings suggest that DD hepatitis B revaccination series should be given in HIV-infected patients who were at least 40 years old or had CD4 counts less than 450 cells/µL after no response to the first vaccination series.

Vaccination coverage and immunity against hepatitis B among HIV-infected patients in South Brazil

Evidence-based strategies to improve the hepatitis B virus (HBV) vaccination coverage rates might help to reduce the burden caused by co-infection with HBV and human immunodeficiency virus (HIV). In this study, the aim was to evaluate the vaccination coverage and immunity against HBV among HIV-infected individuals in South Brazil, and identify factors that are associated with compliance patterns and antibody reactivity. Three hundred HIV-infected men and women were included in this survey. The patients answered a standardized questionnaire, and vaccination cards were checked in order to assess hepatitis B vaccine status. A blood sample was collected for quantitative determination of antibody to hepatitis B virus surface antigen (anti-HBs). Participants were also evaluated for their CD4 cell count and HIV viral load. The overall vaccination coverage of HBV vaccination found in this study (57.4%) was lower than that was previously reported in South Brazil. Anti-HBs levels >10 IU/L were observed in 47.0% of the studied population. A significant inequality in the coverage rates and antibody reactivity was found in favor of patients with better economic status. In conclusion, the results indicate the need for improvement in the HBV vaccination coverage among HIV carriers, in particular focusing on low-income individuals.

Travel risk assessment, advice and vaccinations in immunocompromised travellers (HIV, solid organ transplant and haematopoeitic stem cell transplant recipients): A review

International travellers with immunocompromising conditions such as human immunodeficiency virus (HIV) infection, solid organ transplantation (SOT) and haematopoietic stem cell transplantation (HSCT) are at a significant risk of travel-related illnesses from both communicable and non-communicable diseases, depending on the intensity of underlying immune dysfunction, travel destinations and activities. In addition, the choice of travel vaccinations, timing and protective antibody responses are also highly dependent on the underlying conditions and thus pose significant challenges to the health-care providers who are involved in pre-travel risk assessment. This review article provides a framework of understanding and approach to aforementioned groups of immunocompromised travellers regarding pre-travel risk assessment and management; in particular travel vaccinations, infectious and non-infectious disease risks and provision of condition-specific advice; to reduce travel-related mortality and morbidity.