Safety and immunogenicity of varying dosages of trivalent inactivated influenza vaccine administered by needle-free jet injectors

Devices to overcome the buccal mucosal barrier to administer therapeutic peptides

Peptide therapeutics are important in healthcare owing to their high target specificity, therapeutic efficacy, and relatively low side effect profile. Injections of these agents have improved thetreatment of chronic diseases including autoimmune, metabolic disorders, and cancer. However, their administration via injections can prove a barrier to patient acceptability of treatments. While oral delivery of these molecules is preferable, oral peptide formulations are associated with limited bioavailability due to degradation in the intestine and low epithelial permeability. Buccal administration of peptides is a potential alternative to injections and oral formulations. Similar to the oral route, the buccal route can promote better patient adherence to dosing regimens, along with the added advantages of not requiring restriction on food or drink consumption before and after administration, as well as avoidance of the liver first-pass metabolism. However, like oral, effective buccal absorption of peptides is still challenging due to the high epithelial permeability barrier. We present a multidisciplinary approach to understanding the buccal physiological barrier to macromolecule permeation and discuss how engineered devices may overcome it. Selected examples of buccal devices can facilitate fast and efficient macromolecule absorption through multiple mechanisms including physical disruption of epithelia, convection-based mass transfer, and a combination of physicochemical strategies. Importantly, minimally invasive devices can be self-applied and are associated with the maintenance of the barrier after exposure. We analysed the critical attributes that are required forthe clinical translation of buccal peptide administration devices. These include performance-driven device development, manufacturing features, patient acceptability, and commercial viability.

Microarray patches: scratching the surface of vaccine delivery

INTRODUCTION

Microneedles are emerging as a promising technology for vaccine delivery, with numerous advantages over traditional needle and syringe methods. Preclinical studies have demonstrated the effectiveness of MAPs in inducing robust immune responses over traditional needle and syringe methods, with extensive studies using vaccines targeted against different pathogens in various animal models. Critically, the clinical trials have demonstrated safety, immunogenicity, and patient acceptance for MAP-based vaccines against influenza, measles, rubella, and SARS-CoV-2.

AREAS COVERED

This review provides a comprehensive overview of the different types of microarray patches (MAPs) and analyses of their applications in preclinical and clinical vaccine delivery settings. This review also covers additional considerations for microneedle-based vaccination, including adjuvants that are compatible with MAPs, patient safety and factors for global vaccination campaigns.

EXPERT OPINION

MAP vaccine delivery can potentially be a game-changer for vaccine distribution and coverage in both high-income and low- and middle-income countries. For MAPs to reach this full potential, many critical hurdles must be overcome, such as large-scale production, regulatory compliance, and adoption by global health authorities. However, given the considerable strides made in recent years by MAP developers, it may be possible to see the first MAP-based vaccines in use within the next 5 years.

Electromagnetic Force-Driven Needle-Free in Ovo Injection Device

Needle-free injections are mainly used for administering human or mammalian vaccines or drugs. However, poultry vaccines, in ovo injections to embryos, subcutaneous injections to chickens, and intramuscular injections are administered using needle injections. This article presents a new needle-free in ovo injection device method that uses push-pull solenoids to eject liquid jets, mainly for embryonic eggs of chickens. Furthermore, our study investigated the suitable jet pressures for using this method and the post-injection hatching rates in 18-day-old embryonic eggs. Using this method, we could deliver the liquid to the allantoic and amniotic cavities or the muscle tissue through the egg membrane of the air chamber using a jet pressure of ~6–7 MPa or ~8 MPa. After injecting 0.25 mL of 0.9% saline into 18-day-old Lohmann breed layer embryonic eggs and specific pathogen-free (SPF) embryonic eggs at a jet pressure of ~7 MPa, we observed hatching rates of 98.3% and 85.7%, respectively. This study’s electromagnetic needle-free in ovo injection device can apply vaccine or nutrient solution injection for embryo eggs and serve as a reference for future studies on needle-free in ovo injection automation systems, jet pressure control, and injection pretreatment processes.

Is there a difference in the immune response, efficacy, effectiveness and safety of seasonal influenza vaccine in males and females? - A systematic review

INTRODUCTION

Seasonal influenza is an important cause of morbidity and mortality, despite being vaccine-preventable. Sex factors (genes and hormones) seem to impact individuals' susceptibility to infectious diseases and their response to vaccination. However, most vaccine studies do not explicitly assess sex differences in vaccine response, but rather adjust for sex.

METHODS

We conducted a systematic review to analyze immunogenicity, efficacy, effectiveness and/or safety of seasonal influenza vaccine data stratified by sex. We searched PubMed, EMBASE, CINAHL, Web of Science and clinicaltrials.gov for observational studies and phase III/IV trials from January 1990 to June 2018, published in English or French. Two reviewers independently screened all references, then proceeded to data extraction and quality assessment using the Cochrane tools (RoB and ROBINS-I) on included studies.

RESULTS

Of the 5,745 citations retrieved, 46 studies were included in the SR. Overall, 18 studies assessed immunogenicity, 1 estimated efficacy, 6 measured effectiveness and 25 evaluated safety of seasonal influenza vaccine in females and males (four studies reported on two sex-stratified outcomes concomitantly).

CONCLUSION

No clear conclusion could be drawn regarding the effect of sex on the immunogenicity and effectiveness of seasonal influenza vaccine, but higher rates of adverse events following immunization (AEFIs) were reported in females. The heterogeneity of data and studies' low quality prevented us from conducting a meta-analysis. There is a need to emphasize on the appropriate use of the terms sex and gender in biomedical research. Evidence of higher quality is needed to better understand sex differences in response to influenza vaccine.

Novel approaches for the design, delivery and administration of vaccine technologies

It is easy to argue that vaccine development represents humankind's most important and successful endeavour, such is the impact that vaccination has had on human morbidity and mortality over the last 200 years. During this time the original method of Jenner and Pasteur, i.e. that of injecting live-attenuated or inactivated pathogens, has been developed and supplemented with a wide range of alternative approaches which are now in clinical use or under development. These next-generation technologies have been designed to produce a vaccine that has the effectiveness of the original live-attenuated and inactivated vaccines, but without the associated risks and limitations. Indeed, the method of development has undoubtedly moved away from Pasteur's three Is paradigm (isolate, inactivate, inject) towards an approach of rational design, made possible by improved knowledge of the pathogen-host interaction and the mechanisms of the immune system. These novel vaccines have explored methods for targeted delivery of antigenic material, as well as for the control of release profiles, so that dosing regimens can be matched to the time-lines of immune system stimulation and the realities of health-care delivery in dispersed populations. The methods by which vaccines are administered are also the subject of intense research in the hope that needle and syringe dosing, with all its associated issues regarding risk of injury, cross-infection and patient compliance, can be replaced. This review provides a detailed overview of new vaccine vectors as well as information pertaining to the novel delivery platforms under development.

Needle-Free and Needle-Based Growth Hormone Therapy in Children: A Pooled Analysis of Three Long-Term Observational Studies

BACKGROUND

Treatment with growth hormone (GH) is standard clinical practice in children with GH deficiency (GHD) or Turner syndrome (TS). Hitherto, no long-term data on auxological outcome and safety of Zomacton® have been published. Data comparing needle-free administration (NF) and needle injection (NI) of GH are very sparse.

AIMS

To analyse longitudinal auxological outcome and safety data of GH treatment-naïve patients diagnosed with GHD or TS and to compare NF and NI in a real-life setting.

METHODS

Pooled auxological data and safety information from three consecutive prospective observational Zomacton® studies covering 22 years of treatment were analysed and NF was compared to NI.

RESULTS

The safety cohort comprised 1,595 patients who received at least one GH dose. The auxological outcome cohort comprised 856 treatment-naïve patients with follow-up data ≥12 months. Height-SDS and height velocity improved significantly during the first 3 years of treatment. Documented choice of device was available for 658 patients (NF 69.1%, NI 30.9%). NF administration was non-inferior to NI. No previously unknown safety signals occurred.

CONCLUSION

Real-life data show that treatment with Zomacton® improves auxological outcome parameters without new safety concerns. NF administration of GH represents a useful alternative to NI in children with growth disorders.

Reduction in Lesion Incidence in Pork Carcass Using Transdermal Needle-free Injection of Foot-and-Mouth Disease Vaccine

Foot-and-mouth disease (FMD) is an infectious disease affecting pigs. The control of FMD in swine husbandry is very important because its outbreak results in a vast economic loss. FMD vaccination has effectively controlled FMD; however, it results in economic loss associated with the incidence of lesions in the pork meat at the injection site. The objective of this study was to investigate the effects of transdermal needle-free injection (NFI) of the FMD vaccine on the incidence of lesions at the injection site. Pigs (n=493) in the control group were vaccinated with the FMD vaccine using a commercial syringe needle, while 492 pigs in the transdermal NFI group received the FMD vaccine using a needle-free gas-powered jet injector. After the slaughter of the pigs, the incidence of lesions at the injection site of all pigs was checked by plant workers. The result of this study showed that the incidence of lesions in the pork ham from pigs vaccinated with NFI was 14.82% lower than that in control pigs (p<0.01). In addition, lesions generated in the NFI group were found just in the subcutaneous tissue. Therefore, the incidence of lesions at the injection site in pork from pigs vaccinated with the FMD vaccine can be effectively reduced by using transdermal NFI rather than a conventional syringe needle.

The Confluence of Sex Hormones and Aging on Immunity

The immune systems of post-pubescent males and females differ significantly with profound consequences to health and disease. In many cases, sex-specific differences in the immune responses of young adults are also apparent in aged men and women. Moreover, as in young adults, aged women develop several late-adult onset autoimmune conditions more frequently than do men, while aged men continue to develop many cancers to a greater extent than aged women. However, sex differences in the immune systems of aged individuals have not been extensively investigated and data addressing the effectiveness of vaccinations and immunotherapies in aged men and women are scarce. In this review, we evaluate age- and sex hormone-related changes to innate and adaptive immunity, with consideration about how this impacts age- and sex-associated changes in the incidence and pathogenesis of autoimmunity and cancer as well as the efficacy of vaccination and cancer immunotherapy. We conclude that future preclinical and clinical studies should consider age and sex to better understand the ways in which these characteristics intersect with immune function and the resulting consequences for autoimmunity, cancer, and therapeutic interventions.

Heat: A Highly Efficient Skin Enhancer for Transdermal Drug Delivery

Advances in materials science and bionanotechnology have allowed the refinements of current drug delivery systems, expected to facilitate the development of personalized medicine. While dermatological topical pharmaceutical formulations such as foams, creams, lotions, gels, etc., have been proposed for decades, these systems target mainly skin-based diseases. To treat systemic medical conditions as well as localized problems such as joint or muscle concerns, transdermal delivery systems (TDDSs), which use the skin as the main route of drug delivery, are very appealing. Over the years, these systems have shown to offer important advantages over oral as well as intravenous drug delivery routes. Besides being non-invasive and painless, TDDSs are able to deliver drugs with a short-half-life time more easily and are well adapted to eliminate frequent administrations to maintain constant drug delivery. The possibility of self-administration of a predetermined drug dose at defined time intervals makes it also the most convenient personalized point-of-care approach. The transdermal market still remains limited to a narrow range of drugs. While small and lipophilic drugs have been successfully delivered using TDDSs, this approach fails to deliver therapeutic macromolecules due to size-limited transport across the stratum corneum, the outermost layer of the epidermis. The low permeability of the stratum corneum to water-soluble drugs as well as macromolecules poses important challenges to transdermal administration. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to iontophoresis and microneedle-based concepts, thermal-based approaches have shown great promise to enhance transdermal drug delivery of different therapeutics. In this inaugural article for the section "Frontiers in Bioengineering and Biotechnology," the advances in this field and the handful of examples of thermal technologies for local and systemic transdermal drug delivery will be discussed and put into perspective.

Nanomaterials for transdermal drug delivery: beyond the state of the art of liposomal structures

A wide range of biomedical materials have been proposed to meet the different needs for controlled oral or intravenous drug delivery. The advantages of oral delivery such as self-administration of a pre-determined drug dose at defined time intervals makes it the most convenient means for the delivery of small molecular drugs. It fails however to delivery therapeutic macromolecules due to rapid degradation in the stomach and size-limited transport across the epithelium. The primary mode of administration of macromolecules is presently via injection. This administration mode is not without limitations, as the invasive nature of injections elicits pain and decreases patients' compliance. Alternative routes for drug delivery have been looked for, one being the skin. Delivery of drugs via the skin is based on the therapeutics penetrating the stratum corneum (SC) with the advantage of overcoming first-pass metabolism of drugs, to deliver drugs with a short-half-life time more easily and to eliminate frequent administrations to maintain constant drug delivery. The transdermal market still remains limited to a narrow range of drugs. The low permeability of the SC to water-soluble and macromolecular drugs poses significant challenges to transdermal administration via passive diffusion through the skin, as is the case for all topically administered drug formulations intended to bring the therapeutic into the general circulation. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to the integration of skin enhancers into pharmaceutical formulations, nanoparticles based on lipid carriers have been widely considered and reviewed. While being briefly reviewed here, the main focus of this article is on current advancements using polymeric and metallic nanoparticles. Next to these passive technologies, the handful of active technologies for local and systemic transdermal drug delivery will be discussed and put into perspective. While passive approaches dominate the literature and the transdermal market, active delivery based on microneedles or iontophoresis approaches have shown great promise for transdermal drug delivery and have entered the market, in the last decade. This review gives an overall idea of the current activities in this field.

Safety and immunogenicity of a mRNA rabies vaccine in healthy adults: an open-label, non-randomised, prospective, first-in-human phase 1 clinical trial

BACKGROUND

Vaccines based on mRNA coding for antigens have been shown to be safe and immunogenic in preclinical models. We aimed to report results of the first-in-human proof-of-concept clinical trial in healthy adults of a prophylactic mRNA-based vaccine encoding rabies virus glycoprotein (CV7201).

METHODS

We did an open-label, uncontrolled, prospective, phase 1 clinical trial at one centre in Munich, Germany. Healthy male and female volunteers (aged 18-40 years) with no history of rabies vaccination were sequentially enrolled. They received three doses of CV7201 intradermally or intramuscularly by needle-syringe or one of three needle-free devices. Escalating doses were given to subsequent cohorts, and one cohort received a booster dose after 1 year. The primary endpoint was safety and tolerability. The secondary endpoint was to determine the lowest dose of CV7201 to elicit rabies virus neutralising titres equal to or greater than the WHO-specified protective antibody titre of 0·5 IU/mL. The study is continuing for long-term safety and immunogenicity follow-up. This trial is registered with ClinicalTrials.gov, number NCT02241135.

FINDINGS

Between Oct 21, 2013, and Jan 11, 2016, we enrolled and vaccinated 101 participants with 306 doses of mRNA (80-640 μg) by needle-syringe (18 intradermally and 24 intramuscularly) or needle-free devices (46 intradermally and 13 intramuscularly). In the 7 days post vaccination, 60 (94%) of 64 intradermally vaccinated participants and 36 (97%) of 37 intramuscularly vaccinated participants reported solicited injection site reactions, and 50 (78%) of 64 intradermally vaccinated participants and 29 (78%) of 37 intramuscularly vaccinated participants reported solicited systemic adverse events, including ten grade 3 events. One unexpected, possibly related, serious adverse reaction that occurred 7 days after a 640 μg intramuscular dose resolved without sequelae. mRNA vaccination by needle-free intradermal or intramuscular device injection induced virus neutralising antibody titres of 0·5 IU/mL or more across dose levels and schedules in 32 (71%) of 45 participants given 80 μg or 160 μg CV7201 doses intradermally and six (46%) of 13 participants given 200 μg or 400 μg CV7201 doses intramuscularly. 1 year later, eight (57%) of 14 participants boosted with an 80 μg needle-free intradermal dose of CV7201 achieved titres of 0·5 IU/mL or more. Conversely, intradermal or intramuscular needle-syringe injection was ineffective, with only one participant (who received 320 μg intradermally) showing a detectable immune response.

INTERPRETATION

This first-ever demonstration in human beings shows that a prophylactic mRNA-based candidate vaccine can induce boostable functional antibodies against a viral antigen when administered with a needle-free device, although not when injected by a needle-syringe. The vaccine was generally safe with a reasonable tolerability profile.

FUNDING

CureVac AG.

Safety and immunogenicity of a modified vaccinia Ankara vaccine using three immunization schedules and two modes of delivery: A randomized clinical non-inferiority trial

INTRODUCTION

To guide the use of modified vaccinia Ankara (MVA) vaccine in response to a release of smallpox virus, the immunogenicity and safety of shorter vaccination intervals, and administration by jet injector (JI), were compared to the standard schedule of administration on Days 1 and 29 by syringe and needle (S&N).

METHODS

Healthy adults 18-40years of age were randomly assigned to receive MVA vaccine subcutaneously by S&N on Days 1 and 29 (standard), Days 1 and 15, or Days 1 and 22, or to receive the vaccine subcutaneously by JI on Days 1 and 29. Blood was collected at four time points after the second vaccination for plaque reduction neutralization test (PRNT) (primary endpoint) and ELISA (secondary endpoint) antibody assays. For each subject, the peak PRNT (or ELISA) titer was defined by the highest PRNT (or ELISA) titer among all available measurements post second vaccination. Non-inferiority of a non-standard arm compared to the standard arm was met if the upper limit of the 98.33% confidence interval of the difference in the mean log₂ peak titers between the standard and non-standard arm was less than 1.

RESULTS

Non-inferiority of the PRNT antibody response was not established for any of the three non-standard study arms. Non-inferiority of the ELISA antibody response was established for the Day 1 and 22 compressed schedule and for administration by JI. Solicited local reactions, such as redness and swelling, tended to be more commonly reported with JI administration. Four post-vaccination hypersensitivity reactions were observed.

CONCLUSIONS

Evaluations of the primary endpoint of PRNT antibody responses do not support alternative strategies of administering MVA vaccine by S&N on compressed schedules or administration by JI on the standard schedule.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01827371.

Reduced-Dose Influenza Vaccine

Objective:

To evaluate the effectiveness and safety of reduced-dose trivalent inactivated influenza vaccine in adults.

Data Sources:

A MEDLINE search was conducted (1966–May 2006) using the key search terms inactivated, trivalent, influenza vaccine, dose, and intradermal.

Data Synthesis:

Four recent studies evaluated the safety and effectiveness of reduced-dose, inactivated, trivalent influenza vaccine. Reduced doses had immunogenicity similar to that of standard dose vaccination in healthy individuals less than 60 years old. Intramuscular administration caused fewer local adverse effects compared with the other routes of administration. The differences in vaccine administration and dosing used in these studies limit the comparison of their results.

Conclusions:

The Centers for Disease Control and Prevention does not recommend vaccinating with reduced-dose influenza vaccine. If reduced-dose vaccination is to be employed during times of vaccine shortage, it should be administered only to healthy adults under the age of 60, and the intramuscular route is preferred.

Dissolving microneedles for DNA vaccination: Improving functionality via polymer characterization and RALA complexation

DNA vaccination holds the potential to treat or prevent nearly any immunogenic disease, including cancer. To date, these vaccines have demonstrated limited immunogenicity in vivo due to the absence of a suitable delivery system which can protect DNA from degradation and improve transfection efficiencies in vivo. Recently, microneedles have been described as a novel physical delivery technology to enhance DNA vaccine immunogenicity. Of these devices, dissolvable microneedles promise a safe, pain-free delivery system which may simultaneously improve DNA stability within a solid matrix and increase DNA delivery compared to solid arrays. However, to date little work has directly compared the suitability of different dissolvable matrices for formulation of DNA-loaded microneedles. Therefore, the current study examined the ability of 4 polymers to formulate mechanically robust, functional DNA loaded dissolvable microneedles. Additionally, complexation of DNA to a cationic delivery peptide, RALA, prior to incorporation into the dissolvable matrix was explored as a means to improve transfection efficacies following release from the polymer matrix. Our data demonstrates that DNA is degraded following incorporation into PVP, but not PVA matrices. The complexation of DNA to RALA prior to incorporation into polymers resulted in higher recovery from dissolvable matrices, and increased transfection efficiencies in vitro. Additionally, RALA/DNA nanoparticles released from dissolvable PVA matrices demonstrated up to 10-fold higher transfection efficiencies than the corresponding complexes released from PVP matrices, indicating that PVA is a superior polymer for this microneedle application.

Delivery methods to increase cellular uptake and immunogenicity of DNA vaccines

DNA vaccines are ideal candidates for global vaccination purposes because they are inexpensive and easy to manufacture on a large scale such that even people living in low-income countries can benefit from vaccination. However, the potential of DNA vaccines has not been realized owing mainly to the poor cellular uptake of DNA in vivo resulting in the poor immunogenicity of DNA vaccines. In this review, we discuss the benefits and shortcomings of several promising and innovative non-biological methods of DNA delivery that can be used to increase cellular delivery and efficacy of DNA vaccines.

Sex and Gender Impact Immune Responses to Vaccines Among the Elderly

In response to the recommended vaccines in older-aged individuals, sex differences occur in response to those that protect against influenza, tetanus, pertussis, shingles, and pneumococcal infections. The efficacy of vaccines recommended for older-aged adults is consistently greater for females than for males. Gender differences as well as biological sex differences can influence vaccine uptake, responses, and outcome in older-aged individuals, which should influence guidelines, formulations, and dosage recommendations for vaccines in the elderly.

Transdermal Drug Delivery: Innovative Pharmaceutical Developments Based on Disruption of the Barrier Properties of the stratum corneum

The skin offers an accessible and convenient site for the administration of medications. To this end, the field of transdermal drug delivery, aimed at developing safe and efficacious means of delivering medications across the skin, has in the past and continues to garner much time and investment with the continuous advancement of new and innovative approaches. This review details the progress and current status of the transdermal drug delivery field and describes numerous pharmaceutical developments which have been employed to overcome limitations associated with skin delivery systems. Advantages and disadvantages of the various approaches are detailed, commercially marketed products are highlighted and particular attention is paid to the emerging field of microneedle technologies.

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.

How sex and age affect immune responses, susceptibility to infections, and response to vaccination

Do men die young and sick, or do women live long and healthy? By trying to explain the sexual dimorphism in life expectancy, both biological and environmental aspects are presently being addressed. Besides age-related changes, both the immune and the endocrine system exhibit significant sex-specific differences. This review deals with the aging immune system and its interplay with sex steroid hormones. Together, they impact on the etiopathology of many infectious diseases, which are still the major causes of morbidity and mortality in people at old age. Among men, susceptibilities toward many infectious diseases and the corresponding mortality rates are higher. Responses to various types of vaccination are often higher among women thereby also mounting stronger humoral responses. Women appear immune-privileged. The major sex steroid hormones exhibit opposing effects on cells of both the adaptive and the innate immune system: estradiol being mainly enhancing, testosterone by and large suppressive. However, levels of sex hormones change with age. At menopause transition, dropping estradiol potentially enhances immunosenescence effects posing postmenopausal women at additional, yet specific risks. Conclusively during aging, interventions, which distinctively consider the changing level of individual hormones, shall provide potent options in maintaining optimal immune functions.

Needle-free delivery of macromolecules through the skin using controllable jet injectors

INTRODUCTION

Transdermal delivery of drugs has a number of advantages in comparison to other routes of administration. The mechanical properties of skin, however, impose a barrier to administration and so most compounds are administered using hypodermic needles and syringes. In order to overcome some of the issues associated with the use of needles, a variety of non-needle devices based on jet injection technology has been developed.

AREAS COVERED

Jet injection has been used primarily for vaccine administration but has also been used to deliver macromolecules such as hormones, monoclonal antibodies and nucleic acids. A critical component in the more recent success of jet injection technology has been the active control of pressure applied to the drug during the time course of injection.

EXPERT OPINION

Jet injection systems that are electronically controllable and reversible offer significant advantages over conventional injection systems. These devices can consistently create the high pressures and jet speeds necessary to penetrate tissue and then transition smoothly to a lower jet speed for delivery of the remainder of the desired dose. It seems likely that in the future this work will result in smart drug delivery systems incorporated into personal medical devices and medical robots for in-home disease management and healthcare.

Safety and immunogenicity of a quadrivalent intradermal influenza vaccine in adults

BACKGROUND

An intradermal (ID) trivalent split-virion influenza vaccine (IIV3-ID) (Fluzone(®) Intradermal, Sanofi Pasteur, Swiftwater, PA) has been available in the US since the 2011/2012 influenza season for adults aged 18-64 years. This study examined whether adding a second B-lineage strain affects immunogenicity and safety.

METHODS

This randomized, double-blind, multicentre trial evaluated the immunogenicity and safety of an intradermal quadrivalent split-virion influenza vaccine (IIV4-ID) in adults 18-64 years of age in the US during the 2012-2013 influenza season. Participants were randomized 2:1:1 to receive a single injection of IIV4-ID, licensed IIV3-ID, or an investigational IIV3-ID containing the alternate B-lineage strain. Haemagglutination inhibition antibody titres were assessed in two-thirds of participants before vaccination and 28 days after vaccination.

RESULTS

1672 participants were vaccinated with IIV4-ID, 837 with licensed IIV3-ID, and 846 with an investigational IIV3-ID. For all four vaccine strains, antibody responses to IIV4-ID were statistically non-inferior to the response to the IIV3-ID vaccines containing the matched strains. For both B strains, post-vaccination antibody responses to IIV4-ID were statistically superior to the responses to IIV3-ID lacking the corresponding B strain. Adverse events were similar for IIV4-ID and IIV3-ID. The most commonly reported solicited reactions were pain, pruritus, myalgia, headache, and malaise; and most were grade 1 or 2 and appeared and resolved within 3 days of vaccination. IIV4-ID was statistically non-inferior to the two pooled IIV3-ID vaccines for the proportions of participants with at least one grade 2 or 3 systemic reaction.

CONCLUSIONS

Antibody responses to the IIV4-ID were non-inferior to IIV3-ID for the A and matched B strains and superior for the unmatched B strains. IIV4-ID was well tolerated without any safety concerns. IIV4-ID may help address an unmet need due to mismatched B strains in previous influenza vaccines.

Homologous boosting with adenoviral serotype 5 HIV vaccine (rAd5) vector can boost antibody responses despite preexisting vector-specific immunity in a randomized phase I clinical trial

Background

Needle-free delivery improves the immunogenicity of DNA vaccines but is also associated with more local reactogenicity. Here we report the first comparison of Biojector and needle administration of a candidate rAd5 HIV vaccine.

Methods

Thirty-one adults, 18–55 years, 20 naive and 11 prior rAd5 vaccine recipients were randomized to receive single rAd5 vaccine via needle or Biojector IM injection at 10¹⁰ PU in a Phase I open label clinical trial. Solicited reactogenicity was collected for 5 days; clinical safety and immunogenicity follow-up was continued for 24 weeks.

Results

Overall, injections by either method were well tolerated. There were no serious adverse events. Frequency of any local reactogenicity was 16/16 (100%) for Biojector compared to 11/15 (73%) for needle injections. There was no difference in HIV Env-specific antibody response between Biojector and needle delivery. Env-specific antibody responses were more than 10-fold higher in subjects receiving a booster dose of rAd5 vaccine than after a single dose delivered by either method regardless of interval between prime and boost.

Conclusions

Biojector delivery did not improve antibody responses to the rAd5 vaccine compared to needle administration. Homologous boosting with rAd5 gene-based vectors can boost insert-specific antibody responses despite pre-existing vector-specific immunity.

Trial Registration

Clinicaltrials.gov NCT00709605 NCT00709605

Overcoming the challenges in administering biopharmaceuticals: formulation and delivery strategies

The formulation and delivery of biopharmaceutical drugs, such as monoclonal antibodies and recombinant proteins, poses substantial challenges owing to their large size and susceptibility to degradation. In this Review we highlight recent advances in formulation and delivery strategies--such as the use of microsphere-based controlled-release technologies, protein modification methods that make use of polyethylene glycol and other polymers, and genetic manipulation of biopharmaceutical drugs--and discuss their advantages and limitations. We also highlight current and emerging delivery routes that provide an alternative to injection, including transdermal, oral and pulmonary delivery routes. In addition, the potential of targeted and intracellular protein delivery is discussed.

Needle-free jet injection for administration of influenza vaccine: a randomised non-inferiority trial

BACKGROUND

Administration of vaccines by needle-free technology such as jet injection might offer an alternative to needles and syringes that avoids the issue of needle phobia and the risk of needle-stick injury. We aimed to assess the immunogenicity and safety of trivalent influenza vaccine given by needle-free jet injector compared with needle and syringe.

METHODS

For this randomised, comparator-controlled trial, we randomly assigned (1:1) healthy adults (aged 18-64 years) who attended one of four employee health clinics in the University of Colorado health system, with stratification by site, to receive one dose of the trivalent inactivated influenza vaccine Afluria given either intramuscularly with a needle-free jet injector (Stratis; PharmaJet, Golden, CO, USA) or with needle and syringe. Randomisation was done with a computer-generated randomisation schedule with a block size of 100. Because of the nature of the study, masking of participants was not possible. Immunogenicity was assessed by measurement of the hemagglutination inhibition antibody titres in serum for the three viral strains included in the vaccine. We included six coprimary endpoints: three strain-specific geometric mean titre ratios and the absolute differences in three strain-specific seroconversion rates. The immune response of the jet injector group was regarded as non-inferior to that of the needle and syringe group if both the upper bound of each of the three 95% CIs for the strain-specific geometric mean titre ratios was 1.5 or less, and the upper bound of the three 95% CIs for the strain-specific seroconversion rate differences was less than 10 percentage points. We used t test for group comparison. This study is registered with ClinicalTrials.gov, number NCT01688921.

FINDINGS

During the 2012-13 influenza season of the northern hemisphere, we allocated 1250 participants to receive vaccination by needle-free jet injector (n=627) or needle and syringe (n=623). In the intention-to-treat immunogenicity population, all participants with two serum samples were included (575 in the jet injector group and 574 in the needle and syringe group). The immune response to Afluria when given by needle-free jet injector met the criteria for non-inferiority for all six coprimary endpoints. The jet injector group met the geometric mean titre criterion for non-inferiority for the A/H1N1, A/H3N2, and B strains (upper bound of the 95% CI for the geometric mean titre ratios were 1·10 for A/H1N1, 1·17 for A/H3N2, and 1·04 for B strains). The jet injector group met the seroconversion rate criterion for non-inferiority for the A/H1N1, A/H3N2, and B strains (upper bound of the 95% CI of the seroconversion rate differences were 6·0% for A/H1N1, 7·0% for A/H3N2, and 5·7% for B strains). We recorded serious adverse events in three participants, none of which were study related.

INTERPRETATION

The immune response to influenza vaccine given with the jet injector device was non-inferior to the immune response to influenza vaccine given with needle and syringe. The device had a clinically acceptable safety profile, but was associated with a higher frequency of local injection site reactions than was the use of needle and syringe. The Stratis needle-free jet injector device could be used as an alternative method of administration of Afluria trivalent influenza vaccine.

FUNDING

Biomedical Advanced Research and Development Authority (BARDA), PATH, bioCSL, and PharmaJet.

HIV DNA Vaccine: Stepwise Improvements Make a Difference

Inefficient DNA delivery methods and low expression of plasmid DNA have been major obstacles for the use of plasmid DNA as vaccine for HIV/AIDS. This review describes successful efforts to improve DNA vaccine methodology over the past ~30 years. DNA vaccination, either alone or in combination with other methods, has the potential to be a rapid, safe, and effective vaccine platform against AIDS. Recent clinical trials suggest the feasibility of its translation to the clinic.

DNA vaccination by intradermal electroporation induces long-lasting immune responses in rhesus macaques

BACKGROUND

A desirable HIV vaccine should induce protective long-lasting humoral and cellular immune responses.

METHODS

Macaques were immunized by env DNA, selected from a panel of recently transmitted SIVmac251 Env using intradermal electroporation as vaccine delivery method and magnitude, breadth and longevity of humoral and cellular immune responses.

RESULTS

The macaques developed high, long-lasting humoral immune responses with neutralizing capacity against homologous and heterologous Env. The avidity of the antibody responses was also preserved over 1-year follow-up. Analysis of cellular immune responses demonstrated induction of Env-specific memory T cells harboring granzyme B, albeit their overall levels were low. Similar to the humoral responses, the cellular immunity was persistent over the ~1-year follow-up.

CONCLUSION

These data show that vaccination by this intradermal DNA delivery regimen is able to induce potent and durable immune responses in macaques.

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.

Intradermal powder immunization with protein-containing vaccines

The central importance for global public health policy of delivering life-saving vaccines for all children makes the development of efficacious and safe needle-free alternatives to hypodermic needles, preferably in a thermostable form, a matter of pressing urgency. This paper comprehensively reviews past in vivo studies on intradermal powder immunization with vaccine formulations that do not require refrigeration. Particular emphasis is given to the immune response in relation to antigen adjuvantation. While needle-free intradermal delivery of vaccines induces a predominantly Th2-type immune response, adjuvants powerfully enhance and modulate the magnitude and nature of the elicited immune response at various effector sites.

Comparison of the immunogenicity of intramuscular versus subcutaneous administration of trivalent inactivated influenza vaccine in individuals with neuromuscular diseases

Individuals with neuromuscular disease show a wide spectrum of muscle pathology. To test the hypothesis that the immune response to trivalent inactivated influenza vaccine is potentially inadequate when given intramuscularly into a fibrosed muscle, this prospective randomized study compared the immunogenicity and safety of the standard intramuscular versus subcutaneous administration of the influenza vaccine in 22 nonambulatory subjects, of whom 10 have been on glucocorticoid therapy. Analysis of hemagglutination inhibition antibody titers showed high prevalence of seroprotection (prevaccination of 82% H1N1, 72% H3N2, 31% B; postvaccination of 100% H1N1, 77% H3N2, 59% B). Geometric mean titer ratios for each antigen showed no significant difference (P > .5) between intramuscular and subcutaneous routes. Seroprotection was not adversely affected by glucocorticoid therapy. Local tolerance was better with subcutaneous route. Larger studies are needed to confirm these preliminary results.

DNA vaccine delivered by a needle-free injection device improves potency of priming for antibody and CD8+ T-cell responses after rAd5 boost in a randomized clinical trial

BACKGROUND

DNA vaccine immunogenicity has been limited by inefficient delivery. Needle-free delivery of DNA using a CO2-powered Biojector® device was compared to delivery by needle and syringe and evaluated for safety and immunogenicity.

METHODS

Forty adults, 18-50 years, were randomly assigned to intramuscular (IM) vaccinations with DNA vaccine, VRC-HIVDNA016-00-VP, (weeks 0, 4, 8) by Biojector® 2000™ or needle and syringe (N/S) and boosted IM at week 24 with VRC-HIVADV014-00-VP (rAd5) with N/S at 10(10) or 10(11) particle units (PU). Equal numbers per assigned schedule had low (≤500) or high (>500) reciprocal titers of preexisting Ad5 neutralizing antibody.

RESULTS

120 DNA and 39 rAd5 injections were given; 36 subjects completed follow-up research sample collections. IFN-γ ELISpot response rates were 17/19 (89%) for Biojector® and 13/17 (76%) for N/S delivery at Week 28 (4 weeks post rAd5 boost). The magnitude of ELISpot response was about 3-fold higher in Biojector® compared to N/S groups. Similar effects on response rates and magnitude were observed for CD8+, but not CD4+ T-cell responses by ICS. Env-specific antibody responses were about 10-fold higher in Biojector-primed subjects.

CONCLUSIONS

DNA vaccination by Biojector® was well-tolerated and compared to needle injection, primed for greater IFN-γ ELISpot, CD8+ T-cell, and antibody responses after rAd5 boosting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00109629.

Frontiers of transcutaneous vaccination systems: novel technologies and devices for vaccine delivery

Transcutaneous immunization (TCI) systems that use the skin's immune function are promising needle-free, easy-to-use, and low-invasive vaccination alternative to conventional, injectable vaccination methods. To develop effective TCI systems, it is essential to establish fundamental techniques and technologies that deliver antigenic proteins to antigen-presenting cells in the epidermis and dermis while overcoming the barrier function of the stratum corneum. In this review, we provide an outline of recent trends in the development of techniques for the delivery of antigenic proteins and of the technologies used to enhance TCI systems. We also introduce basic and clinical research involving our TCI systems that incorporate several original devices.

Devices for overcoming biological barriers: the use of physical forces to disrupt the barriers

Overcoming biological barriers including skin, mucosal membranes, blood brain barrier as well as cell and nuclear membrane constitutes a key hurdle in the field of drug delivery. While these barriers serve the natural protective function in the body, they limit delivery of drugs into the body. A variety of methods have been developed to overcome these barriers including formulations, targeting peptides and device-based technologies. This review focuses on the use of physical methods including acoustic devices, electric devices, high-pressure devices, microneedles and optical devices for disrupting various barriers in the body including skin and other membranes. A summary of the working principles of these devices and their ability to enhance drug delivery is presented.

The safety and effectiveness of self-administration of intranasal live attenuated influenza vaccine in adults

Intranasal live attenuated influenza vaccine (LAIV) has potential for self-administration (SA) by adults and adolescents, which could save time and cost in mass vaccination settings. Participants in a study of LAIV in adults (n=4561) selected either SA or health care provider (HCP) administration and were followed for febrile illness during the influenza season. More LAIV recipients chose SA-LAIV (72%) than HCP-LAIV (28%). Overall, 97% of SA-LAIV and 98% of HCP-LAIV recipients had no problems with vaccine administration. Four of 13 study sites enrolled more than 50 subjects in both cohorts. Overall and for these 4 sites, illness incidence was similar with SA-LAIV and HCP-LAIV. Solicited reactogenicity events and adverse events through 7 days post vaccination were comparable for SA-LAIV and HCP-LAIV recipients; both groups exhibited increased runny nose, sore throat, and cough relative to placebo recipients. SA-LAIV and HCP-LAIV appeared similarly effective against influenza-like illness and had comparable safety profiles.

Immunogenicity and safety of varying dosages of a monovalent 2009 H1N1 influenza vaccine given with and without AS03 adjuvant system in healthy adults and older persons

BACKGROUND

Adjuvanted vaccines have the potential to improve influenza pandemic response. AS03 adjuvant has been shown to enhance the immune response to inactivated influenza vaccines.

METHODS

This trial was designed to evaluate the immunogenicity and safety of an inactivated 2009 H1N1 influenza vaccine at varying dosages of hemagglutinin with and without extemporaneously mixed AS03 adjuvant system in adults ≥ 18 years of age. Adults were randomized to receive 2 doses of 1 of 5 vaccine formulations (3.75 µg, 7.5 µg, or 15 µg with AS03 or 7.5 µg or 15 µg without adjuvant).

RESULTS

The study population included 544 persons <65 years of age and 245 persons ≥ 65 years of age. Local adverse events tended to be more frequent in the adjuvanted vaccine groups, but severe reactions were uncommon. In both age groups, hemagglutination inhibition antibody geometric mean titers after dose one were higher in the adjuvanted groups, compared with the 15 µg unadjuvanted group, and this difference was statistically significant for the comparison of the 15 µg adjuvanted group with the 15 µg unadjuvanted group.

CONCLUSIONS

AS03 adjuvant system improves the immune response to inactivated 2009 H1N1 influenza vaccine in both younger and older adults and is generally well tolerated. ClinicalTrials.gov NCT00963157.

Laser vaccine adjuvant for cutaneous immunization

Simple and efficient technologies for intradermal immunization have recently been developed, making cutaneous vaccination a valid alternative for vaccine delivery. This raises an urgent need for safe and potent adjuvants suitable for cutaneous vaccination. Many traditional adjuvants like aluminum-based adjuvants may not be appropriate for boosting cutaneous immunization because they evoke strong and persistent inflammation in the skin that would potentially breach its integrity with serious consequences. Laser vaccine adjuvant is induced by brief illumination of a small area of the skin with a safe, noninvasive laser prior to intradermal injection of the vaccine into the site of illumination. It does not stimulate overt inflammation or reactogenicity in the skin and boosts immune responses via enhancing the motility of antigen-presenting cells. Laser vaccine adjuvant is convenient, safe and ideal for augmentation of cutaneous immunization and has distinct advantages over conventional adjuvants, in particular when encountering vaccine shortages during an unpredictable event.