Evaluation of immune responses to combined hepatitis A and B vaccine in HIV-infected children and children on immunosuppressive medication

Efficacy, immunogenicity, and safety of available vaccines in children on biologics: A systematic review and meta-analysis

Vaccinations are essential for preventing infectious diseases in children with chronic diseases as they have increased risk of infection from frequent use of biologics. Response to immunizations in this group is not well known.

OBJECTIVE

A systematic review was performed to evaluate three primary outcomes: efficacy; immunogenicity; and safety of vaccines in children with chronic conditions treated with biologics.

METHODS

The protocol for our systematic review and meta-analysis was registered and published with PROSPERO. We searched electronic bibliographic databases for studies published from 2009 to 2019, focusing on vaccinations in children with chronic conditions treated with biologics.

RESULTS

We retrieved 532 records. Thirty-one full-text articles were selected, and 14 were included in the meta-analysis. No significant publication bias was found.

EFFICACY

limited data are available regarding the efficacy of vaccination, as most studies have focused on immunogenicity as surrogate outcome for efficacy. Immunogenicity: patients receiving anti-TNF-alpha therapy had a statistically significant risk of poor seroconversion (p = 0.028) and seroprotection by the serotype B influenza vaccine [inflammatory bowel disease (IBD) p = 0.013; juvenile idiopathic arthritis (JIA) p = 0.004]. We found adequate responses with H1N1 and H3N2 serotypes. Few studies existed for pneumococcal, hepatitis A virus, hepatitis B virus, varicella-zoster virus, Measles Mumps Rubella virus, and multiple vaccine administration.

SAFETY

vaccine administration was not associated with serious side effects, but JIA patients on anti-TNF alpha therapy had a statistically significant risk of presenting with myalgia or arthralgia postinfluenza vaccine (p = 0.014).

CONCLUSIONS

More evidence concerning efficacy, immunogenicity, and safety of vaccinations is needed to guide physicians in the vaccine decision process for this pediatric population.

Immunogenicity and safety of routine vaccines in children and adolescents with rheumatic diseases on immunosuppressive treatment - a systematic review

The immunogenicity of vaccines in children with juvenile autoimmune rheumatic diseases (JARDs) can be reduced, there are additional safety concerns around vaccination, and there is a potential for worsening in disease activity. In this systematic review, we summarise studies that investigated the immunogenicity and safety of routine vaccines in children and adolescents with JARD on immunosuppressive treatment. We identified 37 studies investigating 2571 children and adolescents with JARD on immunosuppressive treatment and 4895 control children. Of the 56 geometric mean antibody titres measured, 19 (34%) were lower, six (11%) higher, and 31 (55%) similar; of the 39 seroprotection rates measured, 10 (26%) were lower, two (5%) higher, and 27 (69%) similar; and of the 27 seroconversion rates measured, nine (33%) were lower, two (8%) higher, and 16 (59%) similar in children with JARD on immunosuppressive treatment compared with control children. However, many of the studies were underpowered, and not designed to show non-inferiority between children with JARD and controls. Subgroup analysis for different types of immunosuppressive treatments was not feasible, as most studies did not report results by treatment. Severe adverse events were reported in 38 children (33 with juvenile idiopathic arthritis, four with systemic lupus erythematosus, and one in a healthy child); most of them were likely not related to the vaccination (e.g. elective hospitalisation or surgery). A worsening in disease activity was reported in 44 (2%) children with JARD; again, many of them were likely not related to the vaccination. There were no safety concerns with live attenuated vaccines; however, only few studies reported results for this.

CONCLUSION

Vaccination in children with JARD on immunosuppressive treatment is safe and should be promoted, especially since these children are at increased risk for infection. The importance for the completion of vaccination schedules should be stressed. Strategies to compensate for the lower vaccine responses, which are found in approximately one-third of these children, include measuring antibody levels to determine the optimal timing for the administration of additional booster doses.

WHAT IS KNOWN

• Children with juvenile autoimmune rheumatic diseases (JARDs) are at higher risk for infections, due to their underlying disease and their immunosuppressive treatment. • In children with JARD, the immunogenicity of vaccines might be reduced, and concerns about safety or the potential for worsening in disease activity after vaccination exist.

WHAT IS NEW

• Our systematic review shows that vaccines in children with JARDs on immunosuppressive treatment are safe and immunogenic. • There are several limitations of the currently published studies, including random timing of measuring vaccine responses and age differences between children with JARD and control groups. Many of the studies were underpowered, and not designed to show non-inferiority between children with JARD and controls.

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.

Immunisation practices in centres caring for children with perinatally acquired HIV: A call for harmonisation

BACKGROUND

Current national immunisation schedules differ between countries in terms of vaccine formulation, timing of vaccinations and immunisation programme funding and co-ordination. As a result, some HIV infected paediatric population may be left susceptible to vaccine preventable infections. Vaccines used in healthy population should be subjected to high quality ethical research and be explicitly validated for use in children with special vaccination needs such as those infected with HIV. This survey was completed to assess current vaccination practices and attitudes toward vaccination among pediatricians who care for vertically HIV infected children.

METHODS

An online questionnaire was completed by 46 experts in paediatric HIV-infection from the Paediatric European Network for Treatment of AIDS (PENTA). Data were collected between November 2013 and March 2014.

RESULTS

46units looking after 2465 patients completed the questionnaire. The majority of units (67%) reported that common childhood immunisation were administered by the family doctor or local health services rather than in the HIV specialist centre. Vaccination histories were mostly incomplete and difficult to obtain for 40% of the studied population. Concerns were reported regarding the use of live attenuated vaccines, such as varicella and rotavirus, and these were less frequently recommended (61% and 28% of the units respectively). Monitoring of vaccine responses was employed in a minority of centres (41%). A range of different assays were used resulting in diverse units of measurement and proposed correlates of protection.

CONCLUSION

Vaccination practices for perinatally HIV-infected children vary a great deal between countries. Efforts should be made to improve communication and documentation of vaccinations in healthcare settings and to harmonise recommendations relating to additional vaccines for HIV infected children and the use of laboratory assays to guide immunisation. This will ultimately improve coverage and vaccine induced immunity in this vulnerable patient group.

Immunogenicity, effectiveness and safety of combined hepatitis A and B vaccine: a systematic literature review

BACKGROUND

Hepatitis A and B are two of the most common vaccine-preventable diseases and vaccination for Hepatitis A virus (HAV) and hepatitis B virus (HBV) is recommended for those at risk of contracting HAV and/or HBV through their occupation, travel or lifestyle.

OBJECTIVE

To describe the vaccine efficacy, immunogenicity, effectiveness and safety of the combined vaccine against hepatitis A and hepatitis B.

METHODS

A systematic review of the literature published between 1990 and 2015.

RESULTS

Anti-HAV seropositivity rates ranged from 96.2% to 100% and anti-HBs seroprotection rates from 82% to 100%. Antibodies persisted up to 15 years and geometric mean concentration (GMC) remained above the seropositivity cut-off value for both. Anti-HAV and anti-HBs immune responses were lower in less immunocompetent individuals one month after completion of the immunization schedule. The safety profiles of Twinrix(TM) and monovalent hepatitis A and B vaccines were similar.

CONCLUSION

The vaccine offers satisfactory long-term immunogenicity rates, expected duration of protection and safety profile similar to the monovalent hepatitis A or B vaccines.