Hepatitis B vaccination in HIV-infected adults: current evidence, recommendations and practical considerations

Safety and immunogenicity of the quadrivalent human papillomavirus vaccine in HIV-1-infected men

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1)-infected men are at increased risk for anal cancer. Human papillomavirus (HPV) vaccination may prevent anal cancer caused by vaccine types.

METHODS

AIDS Malignancy Consortium Protocol 052 is a single-arm, open-label, multicenter clinical trial to assess the safety and immunogenicity of the quadrivalent HPV (types 6, 11, 16, and 18) vaccine in HIV-1-infected men. Men with high-grade anal intraepithelial neoplasia or anal cancer by history or by screening cytology or histology were excluded. Men received 0.5 mL intramuscularly at entry, week 8, and week 24. The primary end points were seroconversion to vaccine types at week 28, in men who were seronegative and without anal infection with the relevant HPV type at entry, and grade 3 or higher adverse events related to vaccination.

RESULTS

There were no grade 3 or greater adverse events attributable to vaccination among the 109 men who received at least 1 vaccine dose. Seroconversion was observed for all 4 types: type 6 (59 [98%] of 60), type 11 (67 [99%] of 68), type 16 (62 [100%] of 62), and type 18 (74 [95%] of 78). No adverse effects on CD4 counts and plasma HIV-1 RNA levels were observed.

CONCLUSIONS

The quadrivalent HPV vaccine appears safe and highly immunogenic in HIV-1-infected men. Efficacy studies in HIV-1-infected men are warranted. Clinical trials registration. NCT 00513526.

Immune activation, apoptosis, and Treg activity are associated with persistently reduced CD4+ T-cell counts during antiretroviral therapy

BACKGROUND

Persistently reduced CD4(+) T-lymphocyte counts in the face of undetectable HIV viremia are seen in a sizable percentage of HIV-infected patients undergoing antiretroviral therapy (ART). We analyzed the immune correlates of this phenomenon.

MATERIALS AND METHODS

Sixty-seven HIV-infected patients with undetectable viremia (<50 copies/microl) after more than 7 years of ART were enrolled in the study and divided into two groups (CD4 cell counts >500 cells/microl or <500 cells/microl). Duration of HIV infection (>16 years) was comparable. Peripheral blood mononuclear cell were stimulated with gag+env or with cytomegalovirus peptides. Activated T cells (Ki67(+)), Treg lymphocytes (CD4(+)/CD25high/Foxp3+), divided into naive and activated cells based on PD1 expression, interleukin (IL)-10 and transforming growth factor (TGF)-beta production, annexin V, activation of caspases 8 and 9, Toll-like receptor (TLR)2 and TLR4 expression on immune cells, and plasma lipopolysaccharide (LPS) concentration were analyzed.

RESULTS

CD4(+)/Ki67(+) T cells; plasma LPS; total, naive, and activated Treg; TLR2-expressing and TLR4-expressing Treg; IL-10 production; and early and late apoptotic CD4 T cells, were significantly increased in patients with undetectable viremia and CD4 cell counts less than 500 cells/microl after more than 7 years of ART. As previously shown, CD4 nadir were also lower in these individuals. Immune activation, LPS concentration, Treg, and degree of apoptosis were negatively correlated with CD4 cell counts.

CONCLUSION

Lack of CD4 recovery in individuals in whom ART suppresses HIV replication is associated with complex immune alterations. Immune activation, likely driven by altered gut permeability and resulting in augmented Treg activity could play a pivotal role in this process.

Immunization for HIV-positive individuals

PURPOSE OF REVIEW

This review summarizes recent literature addressing immunization in the setting of HIV infection, with a specific focus on emerging evidence that can guide the care of HIV-positive adults.

RECENT FINDINGS

There are few controlled studies on the clinical efficacy and effectiveness of vaccination in HIV-infected adults receiving highly active antiretroviral therapy (HAART). Published data indicate that HAART restores vaccine immunogenicity, improving the rates and persistence of immune responses, while reducing the risk of vaccine-related adverse events. Despite effective HAART, responses remain often suboptimal relative to HIV-negative individuals, although they improve with larger and more frequent vaccine doses. New vaccines are undergoing trial with promising results, including novel formulations against hepatitis B. Studies are also under way to explore the role of human papilloma virus vaccines for the prevention of anal cancer.

SUMMARY

Protecting HIV-positive patients against vaccine-preventable infections is important now that HAART has restored life expectancy and general well being, and increased the likelihood of HIV-infected patients engaging in exposure-prone activities related to travel, occupation or social interaction. A proactive approach for vaccinating HIV-positive patients also serves an important public health purpose, reducing the pool of susceptible individuals and contributing to the control of prevalent and re-emerging infections.