Phase 4 randomized trial of intradermal low-antigen-content inactivated influenza vaccine versus standard-dose intramuscular vaccine in HIV-1-infected adults

Effective and Safe Stimulation of Humoral and Cell-Mediated Immunity by Intradermal Immunization with a Cyclic Dinucleotide/Nanoparticle Combination Adjuvant

Intradermal (ID) immunization is an attractive route of vaccination because it targets tissue rich in dendritic cells, has dose-sparing potential, and allows needle-free delivery. However, few adjuvants are effective, nonreactogenic, and compatible with needle-free delivery devices. In this study, we demonstrate that a combination adjuvant composed of cyclic-di-AMP (cdAMP) and the plant-derived nanoparticle adjuvant Nano-11 significantly enhanced the immune response to ID-injected vaccines in mice and pigs with minimal local reaction at the injection site. The cdAMP/Nano-11 combination adjuvant increased Ag uptake by lymph node-resident and migratory skin dendritic cell subpopulations, including Langerhans cells. ID immunization with cdAMP/Nano-11 expanded the population of germinal center B cells and follicular helper T cells in the draining lymph node and Ag-specific Th1 and Th17 cells in the spleen. It elicited an enhanced immune response with a significant increase of IgG1 and IgG2a responses in mice at a reduced dose compared with i.m. immunization. An increased IgG response was observed following needle-free ID immunization of pigs. Nano-11 and cdAMP demonstrated a strong synergistic interaction, as shown in the activation of mouse, human, and porcine APC, with increased expression of costimulatory molecules and secretion of TNF and IL-1β. The combination adjuvant induced robust activation of both NF-κB and IFN regulatory factor signaling pathways and the NLRP3 inflammasome. We conclude that the combination of Nano-11 and cdAMP is a promising adjuvant for ID delivery of vaccines that supports a balanced immune response.

Fractional dose of intradermal compared to intramuscular and subcutaneous vaccination - A systematic review and meta-analysis

BACKGROUND

Vaccine supply shortages are of global concern. We hypothesise that intradermal (ID) immunisation as an alternative to standard routes might augment vaccine supply utilisation without loss of vaccine immunogenicity and efficacy.

METHODS

We conducted a systematic review and meta-analysis searching Medline, Embase and Web of Science databases. Studies were included if: licensed, currently available vaccines were used; fractional dose of ID was compared to IM or SC immunisation; primary immunisation schedules were evaluated; immunogenicity, safety data and/or cost were reported. We calculated risk differences (RD). Studies were included in meta-analysis if: a pre-defined immune correlate of protection was assessed; WHO-recommend schedules and antigen doses were used in the control group; the same schedule was applied to both ID and control groups (PROSPERO registration no. CRD42020151725).

RESULTS

The primary search yielded 5,873 articles, of which 156 articles were included; covering 12 vaccines. Non-inferiority of immunogenicity with 20-60% of antigen used with ID vaccines was demonstrated for influenza (H1N1: RD -0·01; 95% CI -0·02, 0·01; I2 = 55%, H2N3: RD 0·00; 95% CI -0·01, 0·01; I2 = 0%, B: RD -0·00; 95% CI -0·02, 0·01; I2 = 72%), rabies (RD 0·00; 95% CI -0·02, 0·02; I2 = 0%), and hepatitis B vaccines (RD -0·01; 95% CI -0·04, 0·02; I2 = 20%). Clinical trials on the remaining vaccines yielded promising results, but are scarce.

CONCLUSIONS

There is potential for inoculum/antigen dose-reduction by using ID immunisation as compared to standard routes of administration for some vaccines (e.g. influenza, rabies). When suitable, vaccine trials should include an ID arm.

Standard-Dose Intradermal Influenza Vaccine Elicits Cellular Immune Responses Similar to Those of Intramuscular Vaccine in Men With and Those Without HIV Infection

BACKGROUND

Human immunodeficiency virus (HIV)-infected persons are at a higher risk of severe influenza. Although we have shown that a standard-dose intradermal influenza vaccine versus a standard-dose intramuscular influenza vaccine does not result in differences in hemagglutination-inhibition titers in this population, a comprehensive examination of cell-mediated immune responses remains lacking.

METHODS

Serological, antigen-specific B-cell, and interleukin 2-, interferon γ-, and tumor necrosis factor α-secreting T-cell responses were assessed in 79 HIV-infected men and 79 HIV-uninfected men.

RESULTS

The route of vaccination did not affect the immunoglobulin A and immunoglobulin G (IgG) plasmablast or memory B-cell response, although these were severely impaired in the group with a CD4+ T-cell count of <200 cells/μL. The frequencies of IgG memory B cells measured on day 28 after vaccination were highest in the HIV-uninfected group, followed by the group with a CD4+ T-cell count of ≥200 cells/μL and the group with a CD4+ T-cell count of <200 cells/μL. The route of vaccination did not affect the CD4+ or CD8+ T-cell responses measured at various times after vaccination.

CONCLUSIONS

The route of vaccination had no effect on antibody responses, antibody avidity, T-cell responses, or B-cell responses in HIV-infected or HIV-uninfected subjects. With the serological and cellular immune responses to influenza vaccination being impaired in HIV-infected individuals with a CD4+ T-cell count of <200 cells/μL, passive immunization strategies need to be explored to protect this population.

CLINICAL TRIALS REGISTRATION

NCT01538940.

Influenza vaccination for HIV-positive people: Systematic review and network meta-analysis

BACKGROUND

People with Human Immunodeficiency Virus (HIV) are highly susceptible to influenza-related morbidity and mortality. In order to assess comparative efficacy of influenza vaccine strategies among HIV-positive people, we performed a systematic review and Bayesian network meta-analysis (NMA).

METHODS

In this systematic review, we searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL between 1946 and July 2015 for randomized controlled trials (RCTs) on influenza vaccines for HIV-positive adults reporting seroconversion or seroprotection outcomes. The NMAs were conducted within a Bayesian framework and logistic models were used for comparing the effect of the vaccine strategies on the two outcomes.

RESULTS

A total of 1957 publications were identified, 143 were selected for full review, and 13 RCTs were included in our final analysis. Fourteen separate NMAs were conducted by outcomes, vaccine strain, and different outcome measurement timepoints. For example, compared with the 15 μg single vaccine strategy, the odds ratio was the highest for the adjuvant 7.5 μg booster strategy (2.99 [95% credible interval 1.18-7.66]) when comparing seroconversion for H1N1 at 14-41 days after the last dose of vaccination and for the 60 μg single strategy (2.33 [1.31-4.18]) when comparing seroconversion for strain B.

CONCLUSIONS

The adjuvant 7.5 μg booster and 60 μg single vaccine strategies provided better seroconversion and seroprotection outcomes. These findings have important implications for national and international guidelines for influenza vaccination for HIV-positive people and future research.

Vaccinations for the HIV-Infected Adult: A Review of the Current Recommendations, Part I

Vaccination is a critical component for ensuring the health of those living with the human immunodeficiency virus (HIV) by protection against vaccine-preventable diseases. Since HIV-infected persons may have reduced immune responses and shorter durations of protection post-vaccination, HIV-specific guidelines have been published by global and national advisory organizations to address these potential concerns. This article provides a comprehensive review of the current guidelines and evidence-based data for vaccinating HIV-infected adults, including guidance on modified vaccine dosing and testing strategies, as well as safety considerations, to enhance protection among this vulnerable population. In the current article, part I of the two-part series, inactivated vaccines with broad indications as well as vaccines for specific risk and age groups will be discussed.

Safety and immunogenicity of influenza vaccine among HIV-infected adults: Conventional vaccine vs. intradermal vaccine

Several studies have reported poor immune responses to conventional influenza vaccines in HIV-infected individuals. This study sought to elicit more potent immunogenicity in HIV-infected adults using an intradermal vaccine compared with a conventional intramuscular vaccine. This multicenter, randomized, controlled, open-label study was conducted at 3 university hospitals during the 2011/2012 pre-influenza season. Three vaccines were used in HIV-infected adults aged 18 - 60 years: an inactivated intramuscular vaccine (Agrippal), a reduced-content intradermal vaccine (IDflu9μg) and a standard-content intradermal vaccine (IDflu15μg). Serum hemagglutination-inhibiting (HI) antibodies and INF-γ ELISpot assay were measured at the time of vaccination and 1 month after vaccination. Adverse events were recorded for 7 d. A total of 28 Agrippal, 30 IDflu9μg, and 28 IDflu15μg volunteers were included in this analysis. One month after vaccination, the GMTs and differences in INF-γ ELISpot assay results were similar among the 3 groups. Seroprotection rates, seroconversion rates and mean fold increases (MFI) among the 3 groups were also similar, at approximately 80%, 50-60% and 2.5 - 10.0, respectively. All three vaccines satisfied the CHMP criteria for the A/H1N1 and A/H3N2 strains, but not those for the B strain. In univariate analysis, no demographic or clinical factors, including age, CD4+ T-cell counts, HIV viral load, ART status and vaccine type, were related to failure to achieve seroprotection. The three vaccines were all well-tolerated and all reported reactions were mild to moderate. However, there was a tendency toward a higher incidence of local and systemic reactions in the intradermal vaccine groups. The intradermal vaccine did not result in higher immunogenicity compared to the conventional intramuscular vaccine, even with increased antigen dose.

Fluzone® intra-dermal (Intanza®/Istivac® Intra-dermal): An updated overview

Influenza is a highly contagious respiratory acute viral disease which imposes a very heavy burden both in terms of epidemiology and costs, in the developed countries as well as in the developing ones. It represents a serious public health concern and vaccination constitutes an important tool to reduce or at least mitigate its burden. Despite the existence of a broad armamentarium against influenza and despite all the efforts and recommendations of international organisms to broaden immunization, influenza vaccination coverage is still far from being optimal. This, taken together with logistic and technical difficulties that can result into vaccine shortage, makes intra-dermal (ID) vaccines, such as Fluzone® ID and Intanza®, particularly attractive. ID vaccines are comparable and, in some cases, superior to intra-muscular/sub-cutaneous vaccines in terms of immunogenicity, safety, reactogenicity, tolerability and cross-protection profiles, as well as in terms of patient preference, acceptance and vaccine selection. Further advances, such as Fluzone® ID with alternative B strains and Quadrivalent Fluzone® ID or the possibility of self-administering the vaccines, make influenza ID vaccines even more valuable.

Randomized Controlled Trial to Compare Immunogenicity of Standard-Dose Intramuscular Versus Intradermal Trivalent Inactivated Influenza Vaccine in HIV-Infected Men Who Have Sex With Men in Bangkok, Thailand

BACKGROUND

Individuals infected with human immunodeficiency virus (HIV) are at increased risk for severe influenza, yet immune responses to standard-dose intramuscular (IM) influenza vaccine are suboptimal in this population. Intradermal (ID) delivery of influenza vaccine might improve immune response through enhanced stimulation of dendritic cells.

METHODS

We conducted a randomized, double-blind, controlled trial to compare the immunogenicity of off-label standard-dose (15 µg) ID vs standard-dose (15 µg) IM inactive influenza vaccine in HIV-infected men in Bangkok, Thailand. The primary study outcome was seroconversion (minimum titer of 1:40 and ≥4-fold rise in antibody titer) at 1 month postvaccination based on serum hemagglutination inhibition antibody titers against each vaccine strain. Adverse events (AEs) in the 7 days following vaccination were also assessed.

RESULTS

We enrolled 400 HIV-infected participants; 200 were randomly assigned to receive IM and 200 ID vaccine. Vaccine arms were well-balanced with respect to age, CD4 cell count, HIV RNA load, and antiretroviral treatment. Percentage of seroconversion to all (ID 14% vs IM 15%; P = .8) or at least 1 (ID 69% vs IM 68%; P = .7) of the 3 vaccine strains did not differ significantly between ID vs IM vaccine recipients. A higher proportion of participants who received ID vaccine had mild injection-site AEs compared with participants who received IM vaccine (77% vs 27%).

CONCLUSIONS

There were no significant differences in the immunogenicity of standard-dose ID vs IM influenza vaccine in this HIV-infected population in Thailand. Additional strategies to enhance immune responses to influenza vaccine among HIV-infected persons are needed.

CLINICAL TRIALS REGISTRATION

NCT01538940.

Immunogenicity and safety of intradermal influenza vaccine in immunocompromized patients: a meta-analysis of randomized controlled trials

Background

The primary influenza prevention strategy is focused on annual vaccination according to the categories identified in the various countries as being at greatest risk of complications. Many studies were conducted in order to demonstrate that intradermal (ID) vaccine formulation represents a promising alternative to conventional intramuscular (IM) formulation, especially in subjects with an impaired immune system. However, there is no consensus whether the efficacy and safety of ID is equivalent to IM in these subjects. Therefore, we performed a meta-analysis of Randomized Controlled Trials (RCT) to compare the immunogenicity and safety of ID and IM influenza vaccines in subjects with a depleted immune system.

Methods

We conducted a search strategy of medical literature published until November 2014 in order to identify RCTs that evaluated the immunogenicity and safety of ID compared with IM influenza vaccines in immunocompromized patients.

Results

We identified a total of 269 citations through research in electronic databases and scanning reference lists. Of these, 6 articles were included in the meta-analysis, for a total of 673 subjects. The seroprotection rate induced by the ID vaccine is comparable to that elicited by the IM vaccine. The overall RR was 1.00 (95 % CI = 0.91 -1.10) for A/H1N1 strain, 1.00 (95 % CI = 0.90-1.12) for A/H3N2 and 0.99 (95 % CI = 0.84 -1.16) for B strain. No significant differences in the occurrence of systemic reactions were detected (17.7 % in the ID group vs 18.2 % in the IM group) with a pooled RR = 1.00 (95 % CI = 0.67 -1.51), whereas ID administration caused significantly more injection site reactions with a mean frequency of 46 % in the ID group compared to 22 % in the IM group, with a pooled RR = 1.89 (95 % CI = 1.40 -2.57).

Conclusions

The ID influenza vaccine has shown a similar immunogenicity and safety to the IM influenza vaccine in immunocompromized patients, and it may be a valid option to increase compliance to influenza vaccination in these populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1161-z) contains supplementary material, which is available to authorized users.

Effect of vaccine administration modality on immunogenicity and efficacy

The many factors impacting the efficacy of a vaccine can be broadly divided into three categories: features of the vaccine itself, including immunogen design, vaccine type, formulation, adjuvant and dosing; individual variations among vaccine recipients and vaccine administration-related parameters. While much literature exists related to vaccines, and recently systems biology has started to dissect the impact of individual subject variation on vaccine efficacy, few studies have focused on the role of vaccine administration-related parameters on vaccine efficacy. Parenteral and mucosal vaccinations are traditional approaches for licensed vaccines; novel vaccine delivery approaches, including needless injection and adjuvant formulations, are being developed to further improve vaccine safety and efficacy. This review provides a brief summary of vaccine administration-related factors, including vaccination approach, delivery route and method of administration, to gain a better understanding of their potential impact on the safety and immunogenicity of candidate vaccines.

Skin immunization with influenza vaccines

Problems with existing influenza vaccines include the strain specificity of the immune response, resulting in the need for frequent reformulation in response to viral antigenic drift. Even in years when the same influenza strains are prevalent, the duration of immunity is limited, and results in the need for annual revaccination. The immunogenicity of the present split or subunit vaccines is also lower than that observed with whole inactivated virus, and the vaccines are not very effective in high risk groups such as the young or the elderly. Vaccine coverage is incomplete, due in part to concerns about the use of hypodermic needles for delivery. Alternative approaches for vaccination are being developed which address many of these concerns. Here we review new approaches which focus on skin immunization, including the development of needle-free delivery systems which use stable dry formulations and induce stronger and longer-lasting immune responses.

Influenza vaccination in HIV-positive subjects: latest evidence and future perspective

Annual influenza vaccination is recommended for persons with human immunodeficiency virus (HIV) infection. Recent reports indicate that immunizations may increase IIeplication in infected individuals. Generally, vaccination against influenza is well tolerated in both children and adult individuals with HNIVand does not induce significant changes in viral load and CD4+ cell counts. The observed increase in viral replication is usually transient and a clear, measurable progression of the underlying HIV disease is hard to be determined. Several studies reported immunogenicity data in HIV+ population, by comparing diferfent influenza vaccines, adjuvanted or not, and different administration routes. Data are encouraging because an adequate immune response is shown, although split/subunit vaccines do not elicite an efficient immune response in these subjects. New strategies have been evaluated to increase the immune response in immunocompromised patients.The aim of this review is to evaluate tolerability, safety, immunogenicity and efficacy of vaccines actually approved for human use and to consider latest evidence and future perspective in HIV positive subjects.