Skin thickness in young infants and adolescents: Applications for intradermal vaccination

A Retrospective Study of Picosecond Alexandrite Laser Treatment for Acquired Bilateral Nevus of Ota-Like Macules in Children

BACKGROUND

Picosecond lasers have been increasingly applied to the treatment of acquired bilateral nevus of Ota-like macules (ABNOMs), and proved safe and effective for adult patients. But there has been limited data concerned with their use in children.

OBJECTIVE

To analyze the efficacy, safety, and correlative influencing factors of a 755 nm picosecond alexandrite laser in treating ABNOMs in children.

METHODS

We retrospectively analyzed children with ABNOMs from January 2017 to July 2023 who received the treatment using a 755 nm picosecond alexandrite laser. Treatment parameters used were as follows: 750 ps pulse duration, 2.34-4.07 J/cm² fluence, and 2.5-3.3 mm spot size. The mean treatment interval was 7 months. The efficacy was evaluated based on a five-point scale according to the percentage of pigmentation clearance.

RESULTS

A total of 49 pediatric patients were included in this retrospective study. The average age at the beginning of treatment was 16.87 months old (range of 4 months to 59 months). These patients received an average of two treatments, achieving an average of 76% pigment clearance, which corresponded to excellent improvement (75%-94%). After the first treatment, six cases reached clinical clearance, and an average of pigment clearance was 61%. The initial efficacy was positively correlated with Fitzpatrick type (p < 0.05). Patients with Fitzpatrick III skin type responded better than patients with Fitzpatrick IV skin type. Besides, the initial efficacy was negatively correlated with the first treatment age and disease duration (p < 0.05). Eight cases developed postinflammatory hyperpigmentation, accounting for 16.3% of the cases.

CONCLUSION

The 755 nm picosecond alexandrite laser is safe and effective in treating ABNOMs in children. Being younger at the initial treatment, having Fitzpatrick III skin type, and experiencing a shorter disease duration are beneficial for initial efficacy.

Clinical assessment of the potential use of a novel single-dose prefilled injection device for the administration of Acthar Gel in children: a narrative review

Acthar® Gel (repository corticotropin injection; Mallinckrodt Pharmaceuticals, NJ, USA) is indicated for the treatment of myriad inflammatory disorders and is currently administered manually via a vial and syringe. The administration of Acthar via a single-dose prefilled injector (SelfJect™) is intended to simplify its subcutaneous (SC) delivery. The purpose of this review was to determine whether SelfJect is suitable for use in pediatric patients through a literature assessment of various factors, including skin depth, needle length and gauge, dosage, force required for injection, and potential harms. Infants and young children, who commonly have skin-to-muscle distances less than the minimum depth of SelfJect administration, may have risk of unintentional intramuscular (IM) injection; however, an inadvertent IM injection poses no additional risk to children because of the bioequivalence between SC and IM administration of Acthar. The needle gauge of SelfJect is acceptable for pediatric patients and aligns with the Centers for Disease Control and Prevention recommendations for SC injections. The dosage delivered by SelfJect is only appropriate for children over 2 years of age. Although adolescents would likely be able to achieve the minimum force required to remove the protective cap and deliver a full dose of Acthar with SelfJect, an adult (18 years of age and older) should administer SelfJect to pediatric patients. In addition to the commonly reported postmarketing adverse events (AEs) from Acthar administration (e.g., asthenic conditions, fluid retention, insomnia, headache and increased blood glucose), injection site-related AEs common to injection devices may occur with SelfJect use. The risk of needlestick injury from SelfJect is mitigated by a needle guard. In summary, this review of injection device considerations demonstrates that SelfJect is appropriate for use in the pediatric population.

Wound Management of Pediatric Burns

The goal for treating pediatric burns is to allow the patient to heal with as little scarring as possible. Compared to older children and adults, very small children have anatomic differences that alter their treatment. They have thinner skin that leads to a higher risk for full-thickness burns. Children also tend to freeze when touching a hot item, so that the prolonged contact also leads to deeper burns. Two healing strategies are needed to treat these wounds. One must optimize reepithelialization in superficial burns to reduce scarring. Deeper burns require skin grafting, but there are techniques, such as the use of "sheet" autograft skin that lead to excellent outcomes. Strategies to treat the massive pediatric burn will also be covered. Finally, there are instances where different strategies are needed to cover exposed bone or tendon. The ultimate goal is to return the skin to as normal a state as possible.

A cohort analysis of residential radon exposure and melanoma incidence in Switzerland

Radon is a radioactive noble gas found in Earth's crust. It accumulates in buildings, and accounts for approximately half the ionizing radiation dose received by humans. The skin is considerably exposed to ionizing radiation from radon. We aimed to evaluate the association between residential radon exposure and melanoma and squamous cell carcinoma incidence. The study included 1.3 million adults (20 years and older) from the Swiss National Cohort who were residents of the cantons of Vaud, Neuchâtel, Valais, Geneva, Fribourg, and Ticino at the study baseline (December 04, 2000). Cases of primary tumours of skin (melanoma and squamous cell carcinoma) were identified using data from cantonal cancer registries. Long-term residential radon and ambient solar ultraviolet radiation exposures were assigned to each individual's address at baseline. Cox proportional hazard models with age as time scale, adjusted for canton, socioeconomic position, demographic data available in the census, and outdoor occupation were applied. Total and age specific effects were calculated, in the full population and in non-movers, and potential effect modifiers were tested. In total 4937 incident cases of melanoma occurred during an average 8.9 years of follow-up. Across all ages, no increased risk of malignant melanoma or squamous cell carcinoma incidence in relation to residential radon was found. An association was only observed for melanoma incidence in the youngest age group of 20-29 year olds (1.68 [95% CI: 1.29, 2.19] 100 Bq/m3 radon). This association was mainly in women, and in those with low socio-economic position. Residential radon exposure might be a relevant risk factor for melanoma, especially for young adults. However, the results must be interpreted with caution as this finding is based on a relatively small number of melanoma cases. Accumulation of radon is preventable, and measures to reduce exposure and communicate the risks remain important to convey to the public.

A modified tissue expander method for ear reconstruction in patients with excessively insufficient postauricular skin

OBJECTIVE

For microtia patients with excessively insufficient postauricular skin, it is difficult to obtain a satisfied outcome with existing strategies. In this study, we developed a modified tissue expander method for auricular reconstruction.

METHODS

The modified tissue expander method divided into 4 stages. In the first stage, a 30 ml or 50 ml kidney-shaped tissue expander was implanted in the mastoid region. A short time expansion (average 33.5 days) was conducted subsequently. In the second stage, the expander was removed and a modified cartilage framework without tragus was inserted through the same incision. A crescent-shaped cartilage pad was inserted into the incision of cartilage-harvest site at the same time. In the third stage, the reconstructed ear was elevated. Lobule rotation and remanent modification were performed in the fourth stage. The patients were followed up between half a year and 10 years. The outcomes of the reconstructed ears were scored with evaluation criteria.

RESULTS

From January 2010 to December 2019, a total of 45 microtia patients with excessively insufficient postauricular skin were performed the modified tissue expander method. Fourty-two patients showed satisfied outcomes. Complications such as hyperpigmentation in the skin graft area (3, 6.7%), scar hyperplasia (3, 6.7%) and folliculitis (1, 2.2%) were found. There were no complications related to the tissue expander.

CONCLUSION

The modified tissue expander method is an effective and safe technique for auricular reconstruction in patients having excessively insufficient postauricular skin, with satisfying medium-term results.

Dose-sparing effect of Sabin-derived inactivated polio vaccine produced in Japan by intradermal injection device for rats

The live-attenuated oral polio vaccine has long been used as the standard for polio prevention, but in order to minimize the emergence of pathogenic revertants, the inactivated polio vaccine (IPV), which is administered intramuscularly or subcutaneously, is being increasingly demanded worldwide. However, there is a global shortage of IPV, and its cost is an obstacle in developing countries. Therefore, dose-sparing with intradermal administration of IPV has been investigated. In this study, rats were immunized by intradermal (ID) and intramuscular (IM) administration of Sabin-derived inactivated polio vaccine (sIPV) produced in Japan, and the immune responses were evaluated. The results showed that one-fifth (1/5)-dose of ID administration yielded neutralizing antibody titers comparable to the full-dose IM administration, whereas 1/5-dose of IM administration was less effective than the full dose. Furthermore, a vertical puncture-type ID injection device (Immucise) that was originally developed for humans was modified for rats, resulting in successful and stable ID administration into the thin skin of rats. Based on these results, the ID administration of sIPV using Immucise in clinical use is expected to offer benefits such as reduced amounts of vaccine per dose, cost-effectiveness, and thereby the feasibility of vaccination for more people.

Efficacy and safety of Q-switched lasers for the treatment of naevus of Ota in children: a retrospective analysis

To identify factors influencing the efficacy of Q-switched laser in the treatment of naevus of Ota in children and to compare the efficacy, safety, and recurrence rate between 1064 nm Q-switched Nd:YAG laser (QSNL) and 755 nm Q-switched alexandrite laser (QSAL). We retrospectively analysed 160 children with naevus of Ota who completed QSAL or QSNL laser treatment at our centre. Age at initial treatment (P = 0.004), colour of lesions (P = 0.025), and number of treatments (P = 0.002) were related to efficacy. Compared with patients aged 0-11 months at initial treatment, patients who started treatment at 1-3 years (OR adj = 0.47), 4-8 years (OR adj = 0.20), and 9-12 years (OR adj = 0.27) had inferior efficacy. The efficacy of brown-violet (OR adj = 2.67) and blue-violet lesions (OR adj = 2.51) was better than that of brown lesions. Moreover, patients who received 3-4 (OR adj = 2.83) or 5-6 (OR adj = 7.35) treatment sessions showed a better response than those who received 1-2 sessions. Additionally, as the age at initial treatment increased, the rate of complications increased from 2.0 to 14.3%, while the recurrence rate decreased from 8.2 to 0%. In addition, the complication rate increased with an increase in the number of treatments. There were no significant differences in clinical efficacy (P = 0.94), risk of complications (P = 0.752), or recurrence (P = 0.834) between QSAL and QSNL for treating naevus of Ota in children. QSAL and QSNL are equally effective for children's naevus of Ota, with low complications and recurrence rates. Younger age at initial treatment and a greater number of treatments are beneficial for efficacy, whereas brown lesions are a negative factor.

Performance and usability evaluation of novel intradermal injection device Immucise™ and reanalysis of intradermal administration trials of influenza vaccine for the elderly

Under the pandemic situation, there is an urgent need to produce and acquire sufficient quantities of prophylactic vaccines. It becomes important to devise a way to achieve reliable immunity with lower doses to distribute limited supplies of vaccines to maximum number of people very quickly. Intradermal (ID) vaccination is one such method to increase the effectiveness of vaccines. However, this method has not been widely used in general clinical practice because it is technically difficult to inject vaccines precisely into the ID tissue. Therefore, new ID delivery systems that allow reliable ID administration are under development. In this paper, we summarize its design and present the results of performance and usability testing for the Immucise™ Intradermal Injection System (Immucise™). This study showed that Immucise™ can reduce dead volume and inject drugs precisely into the ID tissues of subjects from infants to the elderly and can be used correctly and safely by healthcare professionals. This randomized controlled trial compared ID administration with Immucise™ and standard subcutaneous (SC) administration of seasonal influenza vaccine by analyzing the efficacy of the vaccine in the elderly group at 90 days and 180 days after administration. It was found that the vaccine for the ID group was as effective or more effective than that for the SC group up to 180 days later. It was also found that the geometric mean titer values, especially for B strains, were higher in the two-dose ID group than in the two-dose SC group. These findings suggest that Immucise™ is one of the best devices to distribute a small amount of vaccine quickly and widely to a larger number of people with little loss of vaccine during a pandemic.

Vaccination into the Dermal Compartment: Techniques, Challenges, and Prospects

In 2019, an 'influenza pandemic' and 'vaccine hesitancy' were listed as two of the top 10 challenges to global health by the WHO. The skin is a unique vaccination site, due to its immune-rich milieu, which is evolutionarily primed to respond to challenge, and its ability to induce both humoral and cellular immunity. Vaccination into this dermal compartment offers a way of addressing both of the challenges presented by the WHO, as well as opening up avenues for novel vaccine formulation and dose-sparing strategies to enter the clinic. This review will provide an overview of the diverse range of vaccination techniques available to target the dermal compartment, as well as their current state, challenges, and prospects, and touch upon the formulations that have been developed to maximally benefit from these new techniques. These include needle and syringe techniques, microneedles, DNA tattooing, jet and ballistic delivery, and skin permeabilization techniques, including thermal ablation, chemical enhancers, ablation, electroporation, iontophoresis, and sonophoresis.

Skin thickness in neonates: Implications for intradermal vaccination

INTRODUCTION

Intradermal (ID) injection is an alternate route that enhances vaccine immunogenicity and decreases vaccine dose. Regular immunization usually starts at age 2 months, and the limited immune capacity of neonates and young infants makes them vulnerable to infection. Successful ID vaccine delivery in this population requires knowledge of skin thickness. Although skin thickness has been evaluated in infants aged 2 months or older, no comparable data are available for neonates, including preterm neonates.

METHODS

This prospective observational study used ultrasonography to assess skin thickness in 70 neonates (35 full-term and 35 preterm neonates) at deltoid, suprascapular, and thigh sites. The measurements were compared in relation to anatomical site, between full-term and preterm infants, and with skin thickness values for children aged 2 months or older, which were collected in our previous study using the same measurement technique.

RESULTS

In full-term neonates, skin was significantly thicker at the suprascapular site than at the deltoid and thigh sites (P < 0.05); in preterm neonates, skin was significantly thicker at the suprascapular site than at the thigh site (P < 0.05). Skin thickness values at all three sites were significantly lower in preterm neonates than in full-term neonates (P < 0.05). As compared with skin thickness values for infants aged 2 months, values for full-term neonates were significantly lower for the deltoid and suprascapular sites (P < 0.001).

CONCLUSIONS

Skin thickness values for neonates were affected by prematurity and were significantly lower than those for infants aged 2 months. These findings are important in the design of ID injection devices for neonates and young infants.

Skin thickness measurements for optimal intradermal injections in children

BACKGROUND

In the context of precision medicine and in response to the highly needed capacity of rapid interventions towards new infectious diseases and pandemic outbreaks, intradermal immunization is gaining increased attention. However, the currently used Mantoux technique for ID injection is difficult to standardize and requires training, especially when used in children. To allow determining the maximum penetration depth and needle characteristics for the development of a platform of medical devices suited for intradermal injection, VAX-ID® and to ensure an accurate ID injection in children, the epidermal and dermal thickness at the proximal ventral and dorsal forearm (PVF & PDF) and at the deltoid region in children aged 8 weeks to 18 years were assessed. The lateral part of the upper leg was assessed as well in children aged 8 weeks to 2 years since it is a commonly used injection site in this population.

MATERIALS & METHODS

Mean thickness of the PVF, PDF, lateral part of the upper leg and deltoid were measured using high-frequency ultrasound. Association with gender, age and BMI was assessed using Mann-Whitney U Test, Spearman correlation and Wilcoxon Signed Ranks Test, respectively.

RESULTS

Results showed an overall mean skin thickness of 0.99 mm (SD: 0.14 mm) at the PVF, 1.20 mm (SD: 0.17) at the PDF, 1.28 mm (SD: 0.16) at the lateral part of the upper leg and increasing to 1.32 mm (0.25) at the deltoid region. Age and BMI correlated significantly (p < 0.001) with skin thickness at all investigated body sites. Gender did not affect skin thickness in the investigated population.

CONCLUSION

Significant differences in skin thickness at the PVF, PDF and deltoid region were seen according to age and BMI. An optimal needle length of 0.7 mm is advised to guarantee intradermal injection in children at all investigated injection sites. (NCT02727114).

Medical devices and the pediatric population - a head-to-toe approach

Introduction: This review uses a head-to-toe approach, a standardized approach similar to the format used by clinicians during the physical examination, to highlight important differences between children, adolescents and adults. The assessment of a pediatric patient is significantly different from an adult and the heterogeneity of the pediatric population requires knowledge of the inter- and intra-subpopulation differences in growth and development for all organ systems. Areas covered: A search of the English medical literature (PubMed and EMBASE) resulted in identification and review of articles that reported medical device use in the pediatric population based on specific organ systems. The review highlights unique considerations for the pediatric population with respect to growth and development as well as important physiologic and maturational differences between children and adults pertaining to the use of medical devices. Expert opinion: Children have unique medical device needs; adult devices are often adapted or configured to address these unmet needs. It is important that clinicians, and those who manufacture and design medical devices for the pediatric population, have a heightened awareness of the varied pediatric subpopulations (neonates to adolescents) with respect to growth and development, and the adjustments needed to ensure safe and effective use of devices for their unique needs.

The Impact of Scaling Factor Variability on Risk-Relevant Pharmacokinetic Outcomes in Children: A Case Study Using Bromodichloromethane (BDCM)

Biotransformation rates extrapolated from in vitro data are used increasingly in human physiologically based pharmacokinetic (PBPK) models. This practice requires use of scaling factors, including microsomal content (mg of microsomal protein/g liver, MPPGL), enzyme specific content, and liver mass as a fraction of body weight (FVL). Previous analyses indicated that scaling factor variability impacts pharmacokinetic (PK) outcomes used in adult population dose-response studies. This analysis was extended to pediatric populations because large inter-individual differences in enzyme ontogeny likely would further contribute to scaling factor variability. An adult bromodichloromethane (BDCM) model (Kenyon, E. M., Eklund, C., Leavens, T. L., and Pegram, R. A. (2016a). Development and application of a human PBPK model for bromodichloromethane (BDCM) to investigate impacts of multi-route exposure. J. Appl. Toxicol. 36, 1095-1111) was re-parameterized for neonates, infants, and toddlers. Monte Carlo analysis was used to assess the impact of pediatric scaling factor variation on model-derived PK outcomes compared with adult findings. BDCM dose metrics were estimated following a single 0.05-liter drink of water or a 20-min bath, under typical (5 µg/l) and plausible higher (20 µg/l) BDCM concentrations. MPPGL, CYP2E1, and FVL values reflected the distribution of reported pediatric population values. The impact of scaling factor variability on PK outcome variation was different for each exposure scenario, but similar for each BDCM water concentration. The higher CYP2E1 expression variability during early childhood was reflected in greater variability in predicted PK outcomes in younger age groups, particularly for the oral exposure route. Sensitivity analysis confirmed the most influential parameter for this variability was CYP2E1, particularly in neonates. These findings demonstrate the importance of age-dependent scaling factor variation used for in vitro to in vivo extrapolation of biotransformation rates.

Improving vaccine-related pain, distress or fear in healthy children and adolescents-a systematic search of patient-focused interventions

OBJECTIVE

The WHO recently highlighted the need for research into potential interventions that can be used to mitigate pain during mass vaccinations, in addition to interventions specific for adolescents. The current review examines the literature on potential interventions that can be used during mass vaccination settings in healthy individuals between the ages of 4 and 15 years old.

METHODS

Criteria for inclusion were: 1)participants between the ages of 4-15 years, 2)interventions that were patient-focused, 3)vaccinations in healthy individuals, 4)outcome measures to include self-reported pain, fear or distress.

RESULTS

Twenty-seven articles were identified with a total of 31 interventions. Eleven interventions used injection-site specific interventions, 17 used patient-led interventions and three used a combination of both site-specific and patient-led interventions.

CONCLUSION

Interventions using coolant and vibration together, as well as a combination of site-specific and patient-led interventions, showed the most consistent effects in reducing self-reported pain, fear or distress.

Infant skin maturation: Preliminary outcomes for color and biomechanical properties

BACKGROUND

Newborn infant skin changes after birth but studies have focused on the epidermal barrier. Dermal properties are relevant for care, but literature on postnatal changes is sparse. We further characterized skin maturational changes in lightness, color and response to biomechanical stress.

METHODS

Normal skin sites from subsets of participants in a trial on the progression and stage of infantile hemangiomas were retrospectively examined. Standardized photographs were analyzed as L*, a*, and b* images. Biomechanics were measured with the Cutometer^® .

RESULTS

Color changed significantly with increasing age. Skin was darker and redder at 2.0 vs. 5.4, 8.5 and 12.8 months. Yellow color increased, with higher values at 12.8 vs. 2.0, 3.5 and 5.4 months. Chest tissue was consistently more elastic than arm and face sites, with significantly higher elasticity for the youngest and oldest age groups. Biological elasticity, elastic recovery, and total recovery were significantly greater for the oldest subjects. Viscoelasticity and elastic deformation were lower at 5.5 vs. 8.8 and 17.6 months. Arm viscoelastic creep was highest at 2.8 months.

CONCLUSION

Skin maturation continues into year two. Increasing elasticity and decreasing viscoelasticity may reflect increased collagen structure/function. The findings have implications for prevention of skin injury associated with mechanical forces.

Intradermal vaccination for infants and children

Intradermal (ID) vaccination induces a more potent immune response and requires lower vaccine doses as compared with standard vaccination routes. To deliver ID vaccines effectively and consistently, an ID delivery device has been developed and is commercially available for adults. The clinical application of ID vaccines for infants and children is much anticipated because children receive several vaccines, on multiple occasions, during infancy and childhood. However, experience with ID vaccines is limited and present evidence is sparse and inconsistent. ID delivery devices are not currently available for infants and children, but recent studies have examined skin thickness in this population and reported that it did not differ in proportion to body size in infants, children, and adults. These results are helpful in developing new ID devices and for preparing new vaccines in infants and children.

Superior immunogenicity profile of the new intradermal influenza vaccine compared to the standard subcutaneous vaccine in subjects 65 years and older: A randomized controlled phase III study

BACKGROUND

Although the elderly are at high risk for influenza, the immunogenicity in the elderly is lower than that in younger adults. We developed the new type of seasonal influenza vaccine with the novel intradermal (ID) injection system. In the previous exploratory phase I/II study of the ID vaccine with a dose of 15 μg HA per strain showed the superior immunogenicity profile to that of the standard subcutaneous (SC) injection vaccine in subjects aged 20 years and older.

METHODS

In this multicenter, randomized, double-blind, active controlled study, 900 adults aged 65 years and older were randomized at an equal ratio to either the ID vaccine group or the licensed standard SC vaccine group. Immunogenicity was assessed using serum hemagglutination inhibition (HAI) titers. The co-primary endpoints were the geometrical mean titers (GMT) and the seroconversion rates (SCR) of HAI titers against 3 vaccine strains on Day 21 (21 days after vaccination). To evaluate the early phase immunogenicity, the GMTs and SCRs on Day 7 were also assessed in the same way as the secondary endpoints.

RESULTS

The superiority of the ID vaccine in the GMTs and SCRs were demonstrated in all 3 vaccine strains both on Day 7 and Day 21. The frequency of any injection-site reactions was higher in the ID vaccine group, while the severity of injection-site reactions and the frequency of systemic AEs were comparable between the ID and the SC vaccine groups.

CONCLUSIONS

A single-dose of the influenza vaccine with the novel ID injection system and a dose of 15 μg HA was suggested as an appropriate regimen for clinical use in influenza prevention and associated disease burden reduction. It was also suggested that the new ID vaccine has the potential to replace the standard influenza vaccine from the view point of immunogenicity and safety.

TRIAL REGISTRATION

JAPIC Clinical Trials Information (JapicCTI-142493).

Immunogenicity and safety of the new intradermal influenza vaccine in adults and elderly: A randomized phase 1/2 clinical trial

BACKGROUND

Recent clinical evidence indicates that an intradermal (ID) delivery of vaccines confers superior immunogenicity as compared to a standard intramuscular or subcutaneous (SC) delivery.

METHODS

In this exploratory study, 600 healthy adults were randomized to 6 study groups with subgroups of young adults (20-64 years old) and older adults (65 years and older). The subjects were either injected by a novel ID injection system with a single dose of 6, 9, or 15 μg HA or two doses (21 days apart) of 15 μg HA per strain or injected by an SC injection method with a single or two doses (21 days apart) of 15 μg HA per strain. Immunogenicity was assessed using hemagglutination inhibition (HAI) titer and microneutralization titer on Days 0, 10, 21, and 42. Solicited and unsolicited adverse events were recorded for 7 and 21 days post-vaccination, respectively.

RESULTS

In both young adults and older adults groups, the geometric titer (GMT) ratios of HAI in the ID 15 μg HA group were higher than those in the SC 15 μg HA group on both Day 10 and Day 21, while those in the ID 6 and ID 9 μg HA groups were comparable with those in the SC 15 μg HA group. The kinetics of GMTs of HAI suggested that the ID vaccine has the potential to induce the prompt immune response, which is rather hampered in older adults as seen in the SC vaccine groups. The injection-site AEs were generally mild and transient, and did not occur in a dose or dosage-dependent manner.

CONCLUSIONS

The results of this study clearly suggest that the immunologic profile of the ID vaccine is better than that of the SC vaccine, while the safety profile of the ID vaccine is similar to that of the SC vaccine. In this exploratory study with almost 100 subjects per each group, single or two-dose administration of the ID vaccine containing 15 μg HA was suggested to be an appropriate regimen in order to prevent influenza and to reduce the associated disease burden.

TRIAL REGISTRATION

JAPIC Clinical Trials Information (JapicCTI-132096).