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

Infection prevention in the immunocompromised traveler due to conditions other than transplantation: a review

This narrative review explores the risks related to infection in immunocompromised travelers due to conditions other than transplantation, and evaluates the evidence behind current prophylactic strategies, including immunizations, antimicrobials, and non-pharmacological interventions, to prevent various infection and how the current evidence applies to this special patient population, from the perspective of a US-based traveler.

Common pathogen-associated molecular patterns induce the hyper-activation of NLRP3 inflammasome in circulating B lymphocytes of HIV-infected individuals

OBJECTIVE

Despite the antiretroviral treatment, people with HIV (PWH) still experience systemic chronic inflammation and immune-senescence, which represent risk factors for severe comorbidities and inefficient response to pathogens and vaccines. Given the dysregulation of NLRP3 inflammasome in PWH and the recently demonstrated role played by NLRP3 in B lymphocytes, we hypothesized that NLRP3 dysregulation in B cells can contribute to chronic inflammation and humoral dysfunction in PWH.

DESIGN

NLRP3 inflammasome activation was evaluated in B lymphocytes and correlated with antibodies production and immunization response in PWH.

METHODS

NLRP3 inflammasome activation was compared in B lymphocytes isolated from PWH and healthy donors, in resting and stimulated conditions. Functional polymorphic variants in NLRP3 and IL1B genes were analysed in a cohort of PWH submitted to anti-HBV vaccine to assess the effect of NLRP3 inflammasome on humoral response.

RESULTS

The NLRP3 inflammasome activation in response to common PAMPs (LPS, ß-glucan) resulted higher in B lymphocytes of PWH than in HD. CpG-induced IgM secretion was also increased in B cells of PWH. NLRP3, but not IL1B, gain-of-function polymorphism associated to anti-HBs levels.

CONCLUSION

These data reveal the dysregulation of NLRP3 inflammasome in B lymphocytes of PWH. Differently from myeloid compartment, which present an exhausted NLRP3 inflammasome, the complex appears to be hyper-activated in B cells of PWH, likely contributing to chronic inflammation and affecting humoral response.

Immune response to the hepatitis B vaccine among HIV-infected adults in Uganda

BACKGROUND

Co-infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is common in sub-Saharan Africa (SSA) and can rapidly progress to cirrhosis and hepatocellular carcinoma. Recent data demonstrate ongoing HBV transmission among HIV-infected adults in SSA, suggesting that complications of HIV/HBV co-infection could be prevented with HBV vaccination. Because HBV vaccine efficacy is poorly understood among HIV-infected persons in SSA, we sought to characterize the humoral response to the HBV vaccine in HIV-seropositive Ugandan adults.

METHODS

We enrolled HIV-infected adults in Kampala, Uganda without serologic evidence of prior HBV infection. Three HBV vaccine doses were administered at 0, 1 and 6 months. Anti-HBs levels were measured 4 weeks after the third vaccine dose. "Response" to vaccination was defined as anti-HBs levels ≥ 10 IU/L and "high response" as ≥ 100 IU/L. Regression analysis was used to determine predictors of response.

RESULTS

Of 251 HIV-positive adults screened, 132 (53%) had no prior HBV infection or immunity and were enrolled. Most participants were women [89 (67%)]; median (IQR) age was 32 years (27-41), and 68 (52%) had received antiretroviral therapy (ART) for > 3 months. Median (IQR) CD4 count was 426 (261-583), and 64 (94%) of the 68 receiving ART had undetectable plasma HIV RNA. Overall, 117 (92%) participants seroconverted to the vaccine (anti-HBs ≥ 10 IU/L), with 109 (86%) participants having high-level response (anti-HBs ≥ 100 IU/L). In multivariate analysis, only baseline CD4 > 200 cells/mm3 was associated with response [OR = 6.97 (1.34-34.71), p = 0.02] and high-level response [OR = 4.25 (1.15-15.69)], p = 0.03].

CONCLUSION

HBV vaccination was effective in eliciting a protective humoral response, particularly among those with higher CD4 counts. Half of the screened patients did not have immunity to HBV infection, suggesting a large at-risk population for HBV infection among HIV-positive adults in Uganda. Our findings support including HBV vaccination as part of routine care among HIV-positive adults.

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.

Higher rate of long-term serologic response of four double doses vs. standard doses of hepatitis B vaccination in HIV-infected adults: 4-year follow-up of a randomised controlled trial

BACKGROUND

We previously reported that four doses or four double doses of hepatitis B vaccination regimens could not significantly increase a response rate compared with standard doses. However, the antibody levels were higher in the four doses and four double doses groups. This study followed those patients for at least 3 years and aimed to evaluate the immunogenicity of the three vaccination regimens.

METHODS

HIV-infected adults who had CD4+ cell counts > 200 cells/mm³, undetectable plasma HIV-1 RNA, and negative for all hepatitis B virus markers were randomly assigned to receive one of three recombinant vaccines (Hepavax-Gene^® Berna, Korea) regimens: 20 μg IM at months 0, 1, and 6 (standard doses group, n = 44), 20 μg IM at months 0, 1, 2, 6 (four doses group, n = 44), or 40 μg IM at months 0, 1, 2, and 6 (four double doses group, n = 44) between February 2011 and May 4, 2012. Of 132 participants, 126 were evaluated from August 2015 to January 2016; 42 in the standard doses, 43 in the four doses, and 41 in the four double doses groups.

RESULTS

At a median duration of 49.7 months (range 46.7-53.7) after completion of the primary vaccination schedule, the percentages of responders with anti-HBs ≥ 10 mIU/mL were 57.1% (95% CI 41.5-72.8%) in the standard doses group; 76.7% (95% CI 63.6-89.9%) in the four doses group (P = 0.067 vs. the standard doses group); and 80.5% (95% CI 67.8-93.2%) in the four double doses group (P = 0.033 vs. the standard doses group). Factors associated with a responder were the vaccination schedule (either four doses or four double doses groups) and a younger age.

CONCLUSIONS

Despite the highly effectiveness of the standard hepatitis B vaccination regimen at 6 months after completion, the long-term immunogenicity was lower than the four double doses regimen among HIV-infected adults with CD4+ cell counts > 200 cells/mm³ and undetectable plasma HIV-1 RNA. The standard vaccination regimen may not be the best strategy to provide long-term immune response against hepatitis B virus among HIV-infected individuals. Trial registration NCT1289106, NCT02713620.

Travel vaccination recommendations and infection risk in HIV-positive travellers

BACKGROUND

With the advent of highly active antiretroviral drugs for the treatment of human immunodeficiency virus (HIV) it has become possible for people with HIV to travel to destinations that may place them at risk of a number of infectious diseases. Prevention of infections by vaccination is therefore of paramount importance for these travellers. However, vaccine responsiveness in HIV-positive individuals is not infrequently reduced compared to HIV-negative individuals. An understanding of the expected immune responses to vaccines in HIV-positive travellers is therefore important in planning the best approach to a pretravel consultation.

METHODS

A PubMed search was performed on HIV or acquired immune deficiency syndrome together with a search for specific vaccines. Review of the literature was performed to develop recommendations on vaccinations for HIV-positive travellers to high-risk destinations.

RESULTS

The immune responses to several vaccines are reduced in HIV-positive people. In the case of vaccines for hepatitis A, hepatitis B, influenza, pneumococcus, meningococcus and yellow fever there is a good body of data in the literature showing reduced immune responsiveness and also to help guide appropriate vaccination strategies. For other vaccines like Japanese encephalitis, rabies, typhoid fever, polio and cholera the data are not as robust; however, it is still possible to gain some understanding of the reduced responses seen with these vaccines.

CONCLUSION

This review provides a summary of the immunological responses to commonly used vaccines for the HIV-positive travellers. This information will help guide travel medicine practitioners in making decisions about vaccination and boosting of travellers with HIV.

Management of Hepatitis B Virus Infection: 2018 Guidelines from the Canadian Association for the Study of Liver Disease and Association of Medical Microbiology and Infectious Disease Canada

Hepatitis B virus (HBV) infection is an important public health problem in Canada. In keeping with evolving evidence and understanding of HBV pathogenesis, the Canadian Association for the Study of Liver Disease periodically publishes HBV management guidelines. The goals of the 2018 guidelines are to (1) highlight the public health impact of HBV infection in Canada and the need to improve diagnosis and linkage to care, (2) recommend current best-practice guidelines for treatment of HBV, (3) summarize the key HBV laboratory diagnostic tests, and (4) review evidence on HBV management in special patient populations and include more detail on management of HBV in pediatric populations. An overview of novel HBV tests and therapies for HBV in development is provided to highlight the recent advances in HBV clinical research. The aim and scope of these guidelines are to serve as an up-to-date, comprehensive resource for Canadian health care providers in the management of HBV infection.