Acceptability of microneedle-patch vaccines: A qualitative analysis of the opinions of parents

Vaccine microarray patch self-administration: A preliminary study in adults 50 years of age and over

INTRODUCTION

We assessed the safety, performance, acceptability, and usability of the High-Density Microarray Patch (HD-MAP) for vaccination in adults aged 50 and over.

METHODS

This study was a single-centre, open-label, single-arm intervention in healthy adults aged 50+. HD-MAPs (vaccine-free) were applied by a trained user and self-administered. Participants received one excipient-coated HD-MAP to the volar forearm (FA) and the upper arm (UA) administered by a trained user. Participants then self-administered a HD-MAP to the FA and UA. Application sites were compared for skin response. Participants completed an online survey and participated in a semi-structured interview on acceptability and usability. Analyses were undertaken using descriptive statistics. Interviews were coded in NVivo 12 and subject to thematic analysis. The study occurred from 8 September 2021 to 15 February 2022 in Brisbane, Australia.

RESULTS

Of 44 participants, 43 % (n = 19) were male, and 57 % (n = 25) female. The HD-MAP was well-tolerated, with no treatment-related serious adverse events. The increase in transepidermal water loss following self-administration was similar to that observed for trained user administration (UA: 7.5 fold vs 6-fold, FA: 6.1-fold vs 6.6 fold). Fluorescent dermatoscopy confirmed that HD-MAPs engaged with the skin surface and that self and trained user administrations were similar. All participants found the HD-MAP applicator easy to use. 82 % of participants preferred "vaccination" by HD-MAP should its efficacy be proven equivalent to intramuscular injection (IM). Participants reported high acceptance of the resulting transient marks on the skin (82 %). 98 % of participants agreed that self-administration of the HD-MAP at home, without supervision, was highly preferable for its convenience.

CONCLUSION

HD-MAPs were safe in adults 50+ years, and performance was effective, regardless of administrator. Participants preferred the HD-MAP for its ease of use and convenience in self-administration. This vaccine delivery method shows promise for future implementation for this population.

An Application of an Initial Full Value of Vaccine Assessment Methodology to Measles-Rubella MAPs for Use in Low- and Middle-Income Countries

Measles and rubella micro-array patches (MR-MAPs) are a promising innovation to address limitations of the current needle and syringe (N&S) presentation due to their single-dose presentation, ease of use, and improved thermostability. To direct and accelerate further research and interventions, an initial full value vaccine assessment (iFVVA) was initiated prior to MR-MAPs entering phase I trials to quantify their value and identify key data gaps and challenges. The iFVVA utilized a mixed-methods approach with rapid assessment of literature, stakeholder interviews and surveys, and quantitative data analyses to (i) assess global need for improved MR vaccines and how MR-MAPs could address MR problem statements; (ii) estimate costs and benefits of MR-MAPs; (iii) identify the best pathway from development to delivery; and (iv) identify outstanding areas of need where stakeholder intervention can be helpful. These analyses found that if MR-MAPs are broadly deployed, they can potentially reach an additional 80 million children compared to the N&S presentation between 2030-2040. MR-MAPs can avert up to 37 million measles cases, 400,000 measles deaths, and 26 million disability-adjusted life years (DALYs). MR-MAPs with the most optimal product characteristics of low price, controlled temperature chain (CTC) properties, and small cold chain volumes were shown to be cost saving for routine immunization (RI) in low- and middle-income countries (LMICs) compared to N&S. Uncertainties about price and future vaccine coverage impact the potential cost-effectiveness of introducing MR-MAPs in LMICs, indicating that it could be cost-effective in 16-81% of LMICs. Furthermore, this iFVVA highlighted the importance of upfront donor investment in manufacturing set-up and clinical studies and the critical influence of an appropriate price to ensure country and manufacturer financial sustainability. To ensure that MR-MAPs achieve the greatest public health benefit, MAP developers, vaccine manufacturers, donors, financiers, and policy- and decision-makers will need close collaboration and open communications.

Immunogenicity, safety, usability and acceptability of microarray patches for vaccination: a systematic review and meta-analysis

BACKGROUND

Microarray patches (MAPs) deliver vaccines to the epidermis and the upper dermis, where abundant immune cells reside. There are several potential benefits to using MAPs, including reduced sharps risk, thermostability, no need for reconstitution, tolerability and self-administration. We aimed to explore and evaluate the immunogenicity, safety, usability and acceptability of MAPs for vaccination.

METHODS

We searched CINAHL, Cochrane Library, Ovid Embase, Ovid MEDLINE and Web of Science from inception to January 2023. Eligibility criteria included all research studies in any language, which examined microarrays or microneedles intended or used for vaccination and explored immunogenicity, safety, usability or acceptability in their findings. Two reviewers conducted title and abstract screening, full-text reviewing and data extraction.

RESULTS

Twenty-two studies were included (quantitative=15, qualitative=2 and mixed methods=5). The risk of bias was mostly low, with two studies at high risk of bias. Four clinical trials were included, three using influenza antigens and one with Japanese encephalitis delivered by MAP. A meta-analysis indicated similar or higher immunogenicity in influenza MAPs compared with needle and syringe (N&S) (standardised mean difference=10.80, 95% CI: 3.51 to 18.08, p<0.00001). There were no significant differences in immune cell function between MAPs and N&S. No serious adverse events were reported in MAPs. Erythema was more common after MAP application than N&S but was brief and well tolerated. Lower pain scores were usually reported after MAP application than N&S. Most studies found MAPs easy to use and highly acceptable among healthcare professionals, laypeople and parents.

CONCLUSION

MAPs for vaccination were safe and well tolerated and evoked similar or enhanced immunogenicity than N&S, but further research is needed. Vaccine uptake may be increased using MAPs due to less pain, enhanced thermostability, layperson and self-administration. MAPs could benefit at-risk groups and low and middle-income countries.

PROSPERO REGISTRATION NUMBER

CRD42022323026.

Needle phobia among adult Jordanians: General awareness, prevalence; and exploring microneedles as a promising solution

Needle phobia remains a major drawback of conventional injectable medications, leading to avoidance and low adherence among a reasonable portion of patients. Despite this, there is a limited number of studies investigating needle phobia prevalence and symptoms. In this survey, we studied the knowledge and prevalence of needle phobia and its manifestations among 1182 adult Jordanians. Moreover, we assessed the feasibility of microneedles delivery systems as an alternative approach to conventional injectable methods. The results revealed that 28.5% of the participants identified themselves with needle phobia, with a notably higher prevalence among females compared to males (p-value < 0.001). The overall prevalence of needle phobia based on its measured manifestations was found to be 27.4%. The survey also found that 68% of the population were unfamiliar with the concept of microneedles despite the reasonable proportion of the population who were aware of the disadvantages of conventional injectable medications. Furthermore, the survey identified four significant predictors of needle phobia through hierarchical linear regression analysis. Gender, occupation, and negative past experiences with needle injections accounted for 3%, 1%, and 1% of the variance in needle phobia, respectively. In addition, the participants' preference for microneedles over conventional injectables medications appeared as another significant predictor, contributing 5% of the variance. Overall, the model explained 10% of the variance in needle phobia. Collectively, this study provides an insight into needle phobia prevalence and manifestations in Jordan, while also exploring microneedles as an alternative drug delivery system for patients with needle phobia.

Microneedle-Mediated Transcutaneous Immunization: Potential in Nucleic Acid Vaccination

Efforts aimed at exploring economical and efficient vaccination have taken center stage to combat frequent epidemics worldwide. Various vaccines have been developed for infectious diseases, among which nucleic acid vaccines have attracted much attention from researchers due to their design flexibility and wide application. However, the lack of an efficient delivery system considerably limits the clinical translation of nucleic acid vaccines. As mass vaccinations via syringes are limited by low patient compliance and high costs, microneedles (MNs), which can achieve painless, cost-effective, and efficient drug delivery, can provide an ideal vaccination strategy. The MNs can break through the stratum corneum barrier in the skin and deliver vaccines to the immune cell-rich epidermis and dermis. In addition, the feasibility of MN-mediated vaccination is demonstrated in both preclinical and clinical studies and has tremendous potential for the delivery of nucleic acid vaccines. In this work, the current status of research on MN vaccines is reviewed. Moreover, the improvements of MN-mediated nucleic acid vaccination are summarized and the challenges of its clinical translation in the future are discussed.

Digital Health Interventions to Improve Adolescent HPV Vaccination: A Systematic Review

Digital technologies are being increasingly utilized in healthcare to provide pertinent and timely information for primary prevention, such as vaccination. This study aimed to conduct a systematic review to describe and assess current digital health interventions to promote HPV vaccination among adolescents and parents of adolescents, and to recommend directions for future interventions of this kind. Using appropriate medical subject headings and keywords, we searched multiple databases to identify relevant studies published in English between 1 January 2017 and 31 July 2022. We screened and selected eligible studies for inclusion in the final analysis. We reviewed a total of 24 studies, which included interventions using text messages (4), mobile apps (4), social media and websites (8), digital games (4), and videos (4). The interventions generally improved determinants of HPV vaccination, such as HPV-related knowledge, vaccine-related conversations, and vaccination intentions. In particular, text message and social media interventions targeted improved vaccine uptake behaviors, but little meaningful change was observed. In conclusion, digital health interventions can cost-effectively provide education about HPV vaccination, offer interactive environments to alleviate parental vaccine hesitancy, and ultimately help adolescents engage in HPV vaccine uptake.

Microneedle-Mediated Vaccination: Innovation and Translation

Vaccine administration by subcutaneous or intramuscular injection is the most commonly prescribed route for inoculation, however, it is often associated with some deficiencies such as low compliance, high professionalism, and risk of infection. Therefore, the application of microneedles for vaccine delivery has gained widespread interests in the past few years due to its high compliance, minimal invasiveness, and convenience. This review focuses on recent advances in the development and application of microneedles for vaccination based on different delivery strategies, and introduces the current status of microneedle-mediated vaccination in clinical translation. The prospects for its application including opportunities and challenges are further discussed.

Parent Attitudes about Childhood Vaccines: Point Prevalence Survey of Vaccine Hesitancy in an Irish Population

Understanding parental attitudes to their children’s vaccination is critical to developing and implementing interventions that address parents’ hesitancy and improve vaccine uptake. The Parent Attitudes about Childhood Vaccines (PACV) survey is a validated tool for identifying vaccine hesitancy in parents. We evaluated the rate of vaccine hesitancy and areas of concern regarding childhood vaccinations using an adapted version of the PACV survey, in a convenience sample of parents attending a STEM (Science, Technology, Engineering and Mathematics) outreach event in Ireland, in 2018. A score ≥ 50 identified vaccine hesitant parents. Of 105 parents who completed the survey, the prevalence of vaccine hesitancy was 6.7%, (7/105). Parents had concerns around vaccine side effects (36.2%, n = 38), vaccine safety (20%, n = 21) and the number of vaccines administered (13.3%, n = 14). Parents trusted the vaccine information they received (85.6%, n = 90) and 81.9% (n = 86) believed that the vaccine schedule was good for their child. The findings indicate the presence of vaccine hesitancy in parents in Ireland regarding paediatric vaccines with further research necessary to address parents’ vaccine concerns. Future research should explore further, by qualitative methods, parents’ vaccine concerns. There is also potential to identify vaccine hesitant parents with the PACV survey as a surveillance method in healthcare settings; for example, in community pharmacies, family doctor clinics and out-patient clinics.

Micro array patch (MAP) for the delivery of thermostable vaccines in Australia: A cost/benefit analysis

BACKGROUND

It is anticipated that transforming the vaccine supply chain from syringe-and-needle to thermostable vaccines enabled by Micro Array Patch (MAP) will result in reduced supply chain costs as well as reduced wastes (environmental impact) and improved safety. This paper provides a thorough cost comparison of the conventional syringe-and-needle vaccine supply chain versus the MAP vaccine supply chain for influenza vaccine delivery in Australia.

OBJECTIVE

To determine the potential cost implications and general benefits of replacing syringe-and-needle flu vaccine with MAP-enabled thermostable flu vaccine in Australia.

METHODS

We first provide a snapshot of the existing flu vaccine supply chain in Australia including its limitations and opportunities for improvement. Data/information is collected through interviewing the key stakeholders across vaccine supply chain including vaccine manufacturers, logistics providers, clinics, hospitals, and pharmacies. A cost/benefit analysis of the anticipated supply chain of the MAP-enabled vaccine will reveal the opportunities and challenges of supply chain transformation for flu vaccine delivery in Australia.

FINDINGS

Our high-level practice-informed cost/benefit analysis identifies cold chain removal as an important source of cost saving, but administrative cost savings appear to be even more significant (e.g., time saving for nurses and those involved in cold chain management). Our analysis also identifies the key benefits and limitations of vaccine supply chain transformation in Australia.

CONCLUSION

We conclude that the benefits of moving from syringe-and-needle vaccines to thermostable MAP-delivered vaccines are beyond transportation and storage cost saving. Potential benefits through cost saving, waste reduction, and service level improvement are discussed along with various safety and wellbeing consequences as well as directions for future research in this area.

Transforming the vaccine supply chain in Australia: Opportunities and challenges

BACKGROUND

Analyzing potential benefits of thermostable vaccines delivered through Micro Array Patch (MAP) has received great attention in low and middle-income countries. The experience may or may not be the same in developed countries where the infrastructure is more developed. It is anticipated that transforming the vaccine supply chain from syringe-and-needle to thermostable MAP-delivered vaccines will result in reduced supply chain costs - including manufacturing/supply, logistics/distribution, and administration costs - as well as reduced wastes and improved safety. This paper provides an end-to-end supply chain analysis comparing the key aspects (cost, safety and environmental aspects) of the conventional syringe-and-needle vaccine supply chain with those of the MAP vaccine supply chain for influenza vaccine delivery in Australia. Directions for future research in this area will be provided.

OBJECTIVE

To determine the potential supply chain impacts of replacing syringe-and-needle flu vaccine with MAP-enabled thermostable flu vaccine in Australia.

METHODS

We analyze the current flu vaccine supply chain in Australia to identify practical limitations and opportunities for improvement. Data/information is collected through interviewing the key stakeholders across vaccine supply chain including vaccine manufacturers, logistics providers, clinics, hospitals, and pharmacies.

FINDINGS

A detailed practice-informed analysis is completed on the key operations of the flu vaccine supply chain. Barriers and limitations of the conventional flu vaccine are discussed, along with potential improvements that can be achieved through the implementation of MAP-enabled flu vaccine delivery. We discuss how technology-driven innovations can help advance vaccine supply chains, improve vaccine visibility, reduce wastes, and enable informed decision-making.

CONCLUSION

We find that the benefits of moving from syringe-and-needle vaccines to thermostable MAP-delivered vaccines are beyond transportation and storage cost saving. Potential benefits through cost saving, waste reduction, and service level improvement are discussed along with various safety and wellbeing consequences followed by directions for future research in this area.

Administration of pilocarpine by microneedle patch as a novel method for cystic fibrosis sweat testing

The sweat test is the gold standard for the diagnosis of cystic fibrosis (CF). The test utilizes iontophoresis to administer pilocarpine to the skin to induce sweating for measurement of chloride concentration in sweat. However, the sweat test procedure needs to be conducted in an accredited lab with dedicated instrumentation, and it can lead to inadequate sweat samples being collected in newborn babies and young children due to variable sweat production with pilocarpine iontophoresis. We tested the feasibility of using microneedle (MN) patches as an alternative to iontophoresis to administer pilocarpine to induce sweating. Pilocarpine-loaded MN patches were developed. Both MN patches and iontophoresis were applied on horses to induce sweating. The sweat was collected to compare the sweat volume and chloride concentration. The patches contained an array of 100 MNs measuring 600 μm long that were made of water-soluble materials encapsulating pilocarpine nitrate. When manually pressed to the skin, the MN patches delivered >0.5 mg/cm2 pilocarpine, which was double that administered by iontophoresis. When administered to horses, MN patches generated the same volume of sweat when normalized to drug dose and more sweat when normalized to skin area compared to iontophoresis using a commercial device. Moreover, both MN patches and iontophoresis generated sweat with comparable chloride concentration. These results suggest that administration of pilocarpine by MN patches may provide a simpler and more-accessible alternative to iontophoresis for performing a sweat test for the diagnosis of CF.

Transdermal approaches to vaccinations in the COVID-19 pandemic era

The COVID-19 pandemic has necessitated rapid vaccine development for the control of the disease. Most vaccinations, including those currently approved for COVID-19 are administered intramuscularly and subcutaneously using hypodermic needles. However, there are several disadvantages including pain and fear of needlesticks, the need for two doses, the need for trained health care professionals for vaccine administration, and barriers to global distribution given the need for cold supply chain. Recently, transdermal techniques have been under investigation for vaccines including COVID-19. Microneedle array technology utilizes multiple microscopic projections from a plate which delivers a vaccine in the form of a patch placed on the skin, allowing for painless antigen delivery with improved immune response. In this review, we discuss challenges of existing vaccines and review the literature on the science behind transdermal vaccines including microneedles, current evidence of application in infectious diseases including COVID-19, and considerations for implementation and global access.

Designing a unique feedback mechanism for hydrogel-forming microneedle array patches: a concept study

Although microneedle array patch (MAP) technology is reaching ever closer to regulatory approval, it remains imperative that approaches to further improve patient acceptance are still explored. Addressing this perception, a water-filled reservoir was incorporated into a hydrogel-forming MAP system to provide a novel feedback mechanism. To confirm successful MAP skin insertion, the end user would both hear and feel the rupture of the water-filled reservoir. Interestingly, a 50-µL water-filled reservoir ruptured at 30.27 ± 0.39 N, which has previously been shown as the mean application force for MN insertion in human subjects following appropriate instruction. Importantly, no significant difference in % cumulative permeation of FITC-dextran 10 kDa and fluorescein sodium after 24 h was observed between a 50-µL reservoir and the current method of application that has been successfully used in both in vitro and in vivo studies (p > 0.05). Therefore, as drug delivery was not affected, this proof-of-concept study has shown that a water-filled reservoir feedback mechanism has the potential to serve as a viable tool for consistent MAP skin insertion.

Acceptability of an inactivated influenza vaccine delivered by microneedle patch: Results from a phase I clinical trial of safety, reactogenicity, and immunogenicity

OBJECTIVE

This study sought to evaluate the acceptability of inactivated influenza vaccine delivered by microneedle patch (MNP) in comparison to inactivated influenza vaccine (IIV) delivered by hypodermic needle.

DESIGN, SETTING, AND PARTICIPANTS

From the general population of Atlanta, Georgia, we screened 112 and enrolled 100 healthy adult subjects ages 18 to 49 years. Main Outcome(s) and Measure(s). Our participants were randomized to 4 groups of 25 per arm: (1) IIV by MNP administered by healthcare worker (HCW), (2) IIV by MNP self-administered by study participants, (3) IIV by intramuscular (IM) injection administered by HCW or (4) placebo by MNP administered by HCW. We administered four questionnaires: at Day 0 before and after study product delivery, and at Days 8 and 28.

RESULTS

At baseline, 98.6% of participants receiving MNP vaccination reported an overall positive experience with MNPs, compared to 86.4% for participants receiving IM vaccination. For future influenza vaccination, study participants (N = 99) preferred MNP (n = 65, 69.9%) to injections or nasal spray (n = 20, 21.5%), and the preference for MNP increased from Day 0 to Day 28. Factor analyses resulted in two scaled measures including MNP Use Perceptions (a = 0.799, n = 5 items) and MNP Perceived Convenience (a = 0.844, n = 4 items) that were included in longitudinal assessments; while findings reflect significant differences across treatment groups on mean scores for ease of use, MNP perceived protection, MNP reliability, and MNP selection knowledge, all groups reported their belief that influenza vaccination by MNP would be reliable and protective, as well as easy-to-use and convenient.

CONCLUSIONS AND RELEVANCE

Most participants were accepting of IIV vaccination by MNP and preferred it to injection. Delivery of IIV by MNP may help increase vaccination coverage.

The potential role of using vaccine patches to induce immunity: platform and pathways to innovation and commercialization

Introduction: In the last two decades, the evidence related to using vaccine patches with multiple short projections (≤1 mm) to deliver vaccines through the skin increased significantly and demonstrated their potential as an innovative delivery platform.Areas covered: We review the vaccine patch literature published in English as of 1 March 2019, as well as available information from key stakeholders related to vaccine patches as a platform. We identify key research topics related to basic and translational science on skin physical properties and immunobiology, patch development, and vaccine manufacturing.Expert opinion: Currently, vaccine patch developers continue to address some basic science and other platform issues in the context of developing a potential vaccine patch presentation for an existing or new vaccine. Additional clinical data and manufacturing experience could shift the balance toward incentivizing existing vaccine manufactures to further explore the use of vaccine patches to deliver their products. Incentives for innovation of vaccine patches differ for developed and developing countries, which will necessitate different strategies (e.g. public-private partnerships, push, or pull mechanisms) to support the basic and applied research needed to ensure a strong evidence base and to overcome translational barriers for vaccine patches as a delivery platform.

Skin delivery of trivalent Sabin inactivated poliovirus vaccine using dissolvable microneedle patches induces neutralizing antibodies

The cessation of the oral poliovirus vaccine (OPV) and the inclusion of inactivated poliovirus (IPV) into all routine immunization programmes, strengthens the need for new IPV options. Several novel delivery technologies are being assessed that permit simple yet efficacious and potentially dose-sparing administration of IPV. Current disadvantages of conventional liquid IPV include the dependence on cold chain and the need for injection, resulting in high costs, production of hazardous sharps waste and requiring sufficiently trained personnel. In the current study, a dissolvable microneedle (DMN) patch for skin administration that incorporates trivalent inactivated Sabin poliovirus vaccine (sIPV) was developed. Microneedles were physically stable in the ambient environment for at least 30 min and efficiently penetrated skin. Polio-specific IgG antibodies that were able to neutralize the virus were induced in rats upon administration using trivalent sIPV-containing microneedle patches. These sIPV-patch-induced neutralizing antibody responses were comparable to higher vaccine doses delivered intramuscularly for type 1 and type 3 poliovirus serotypes. Moreover, applying the patches to the flank elicited a significantly higher antibody response compared to their administration to the ear. This study progresses the development of a skin patch-based technology that would simplify vaccine administration of Sabin IPV and thereby overcome logistic issues currently constraining poliovirus eradication campaigns.

Potential use of microarray patches for vaccine delivery in low- and middle- income countries

Microarray patches (MAPs), also referred to as microneedle patches, are a novel methodology that have the potential to overcome barriers to vaccine delivery in low- and middle-income countries (LMICs), and transform the way that vaccines are delivered within immunization programs. The World Health Organization's Initiative for Vaccine Research and its partners are working to understand how MAPs could ease vaccine delivery and increase equitable access to vaccines in LMICs. Global stakeholders have been engaged to evaluate technical, economic, and programmatic challenges; to validate assumptions where possible; and to propose areas of focus to facilitate future vaccine-MAP product development. This report summarizes those learnings.

End-user acceptability study of the nanopatch™; a microarray patch (MAP) for child immunization in low and middle-income countries

A promising new delivery technology, the microarray patch (MAPs) consists of an array of small solid-coated or dissolvable needles, up to one mm in length, that administers a dry formulation of a vaccine or pharmaceutical. This study is not a real-life evaluation study but determines the anticipated acceptability of the Nanopatch™, a solid microarray patch device, in Benin, Nepal and Vietnam for vaccine delivery, and identifies factors that could improve the acceptability of the technology to increase measles immunization coverage. This study combined several evaluation methods, including simulation of vaccine administration on children and in-depth interviews with key stakeholders, healthcare workers, community health volunteers, caretakers, and community representatives. A total of 314 people participated in the study. The overall rate of total acceptability of the patch for child immunization was 92.7%. General opinions were very positive, providing clinical studies confirm that MAP administration is demonstrated to be painless, safe and effective for infectious disease prevention. The study participants were asked to consider the best strategy to introduce such vaccine delivery innovation. Firstly, delivery by skilled healthcare workers at the healthcare facilities will be preferred to establish the technology. Following this, administration by selected volunteers and outreach delivery may be possible, though under the supervision of skilled healthcare workers. This study's protocol received approval from the World Health Organization (WHO) Ethical Research Committee (ERC0002813) and the national IRB in Benin, Nepal and Vietnam.