IM Vaccination Research Articles

Clinical Efficacy of Two Novel, Differentially Administered (IM, ID) Vaccines against Mycoplasma hyopneumoniae and PCV2 in Swine under Field Conditions.

Enzootic pneumonia (EP) of pigs is caused by Mycoplasma hyopneumoniae (M.hp.), which is, together with the porcine circovirus type 2 (PCV2), among the most prominent inducers of the porcine respiratory disease complex (PRDC). Therefore, vaccination of piglets against M.hp. and PCV2 is crucial in the fight against pulmonary infections. In this field study, we tested the clinical efficacy of two novel vaccines, one delivered IM (Hyogen® + Circovac®) and the other ID (MHyo-Sphere®PCV ID), on a fattening farm in Lower Austria with a history of still ongoing EP. Average daily weight gain, coughing/sneezing index, losses due to morbidity/mortality, and lung scoring data at slaughter by means of CLP (Ceva Lung Program) were recorded for three consecutive fattening cohorts to achieve a powerful number of animals, one half each vaccinated with the IM vaccine and the other half with the ID vaccine (n = 659 in total). No statistically significant differences could be observed between the two vaccination groups for the parameters investigated, but the total median EP score, which categorizes pulmonary lesions due to infection by M.hp. with a theoretical range of 0-28, was lowered from initially 1.9 to 1.0, indicating that both vaccines proved very suitable measures in the fight against EP.

A doggy tale: Risk of zoonotic infection with Bordetella bronchiseptica for cystic fibrosis (CF) patients from live licenced bacterial veterinary vaccines for cats and dogs.

Live-attenuated bacterial veterinary vaccines can constitute an infection risk for individuals with any defect in their phagocytic function, including chronic granulomatous disease, leukocyte adhesion deficiency, myeloperoxidase deficiency, as well as Chediak-Higashi syndrome, from accidental acquisition of licenced attenuated live bacterial vaccine, at vaccination or from their vaccinated pet. Ownership of small companion animals, including cats and dogs, is popular within the cystic fibrosis (CF) community. These animals require vaccines as part of their routine care, which may involve live viral and bacterial vaccines, with potential for infection in the CF owner. This report examines the scope of current canine and feline vaccines, with particular emphasis on veterinary vaccination strategies against the Gram-negative pathogen, Bordetella bronchiseptica and describes new vaccine innovations offering protection to both pet and CF owner. The Gram-negative bacterium, Bordetella bronchoseptica, may cause respiratory disease in small companion animals, as well as in certain human vulnerable groups, including those with CF. Live licenced veterinary bacterial vaccines for Bordetella bronchiseptica (Kennel Cough) are available for cats and dogs, which are an infection concern for humans with CF who may come into contact with vaccinated animals. Live licenced veterinary bacterial vaccines for Bordetella bronchiseptica (Kennel Cough) are available for intranasal administration to cats and dogs. These vaccines require a withdrawal period of vaccinated animal from vulnerable owner, ranging from 35days - 11weeks. Recently, a new dead IM vaccine is now available not requiring exclusion of the vaccinated pet from CF owner. CF pharmacists, hospital pharmacists and community pharmacists are important custodians of vaccine-related advice to people with CF, who are frequently consulted for such advice. Pharmacists should be aware of the recent innovations in veterinary medicines, so that they can give appropriate advice to people with CF when asked. Immunocompromised patients, that is those with CF or those with any defect in their phagocytic function (chronic granulomatous disease, leukocyte adhesion deficiency, myeloperoxidase deficiency, Chediak-Higashi syndrome) should avoid exposure to live veterinary bacterial vaccines and seek animal vaccination utilising non-live vaccines. Most importantly, this manuscript highlights the development of a new veterinary vaccine for dogs, which we want to make the CF healthcare community aware of, which is an acellular dead vaccine, so that those patients with dogs needing annual vaccination can select this vaccine pathway, thereby minimising risk of infection from the vaccine strains and avoiding the social exclusion between CF patient and their pet. CF patients should understand the potential infection implications of live-attenuated viral and bacterial strains as vaccines, whether these are small companion animals, exotic animals or large farm animals. Patients should make their veterinarian aware of their CF status, so that a safe and efficacious vaccine strategy is used, both mitigating the potential infection risks from live vaccine components with the CF patient, but simultaneously offering maximum immunological protection to the animal.

P318 Intra-dermal with topical imiquimod pre-treatment versus intra-muscular hepatitis B vaccination in inflammatory bowel disease patients: a double-blind randomized controlled trial

Abstract Background Patients with inflammatory bowel disease (IBD) are often immunocompromised and at risk of various opportunistic infections including viral hepatitis. Vaccination is recommended to prevent hepatitis B infection, but efficacy with conventional intra-muscular hepatitis B vaccination in IBD patients is suboptimal. Intra-dermal vaccination has been shown to be an effective way in augmenting immune response in poor vaccine responders. In addition, topical imiquimod, a synthetic agonist of toll-like receptor 7, has been shown to further boost the immunogenicity when applied to the injection site before intra-dermal vaccination. Our study compared the efficacy of intra-dermal hepatitis B vaccination with topical imiquimod with conventional intra-muscular hepatitis B vaccination in IBD patients. Methods This is a double-blind, randomized-controlled trial. IBD patients with no evidence of active or past infection nor history of vaccination i.e. negative serology to all HBsAg/Anti-HBc/Anti-HBs were recruited. They were randomized in 1:1 ratio to receive either intra-dermal recombinant hepatitis B vaccine with topical imiquimod pre-treatment to site of injection (ID) or intra-muscular recombinant hepatitis B vaccine with topical aqueous cream (IM). Same dose (20mcg) of vaccine (Engerix B, Glaxo Smith Klein) was administered to both groups at 0, 1, 6 month. The primary outcome was the sero-protection rate at 12-month, defined as percentage of recruited subjects with anti-HBs titre ≥ 10 mIU/mL. Results 104 patients (mean age 46; 68% male; 50% Crohn’s and 50% UC) were enrolled, with 53 received ID and 51 received IM vaccine. The percentage of patients using steroids, immunomulators and biologics at the time of randomization was 15, 55 and 22 %, respectively. Baseline demographic, disease characteristic, and laboratory parameter were comparable between the ID and IM groups. Sero-protection rate at 12-month was significantly higher in the ID arm compared to the IM arm (91% vs. 69%, P=0.005; Figure). Percentage of good responders at 12 month (anti-HBs titre > 100 mIU/mL) was also higher in the ID arm than in the IM (77% vs 59%, P=0.042). Multivariate analysis showed that use of ID vaccine (OR 4.45, 95% CI 1.40-14.47) and a higher albumin level (OR 1.30, 95% CI 1.06-1.58) are associated with better sero-protection rate. There was no significant difference in adverse effects reported in (64% in ID vs 55% in IM; Table). Conclusion ID hepatitis B vaccination with topical imiquimod is safe and offers superior seroprotection against hepatitis B among IBD patients.

Effect of Facilitated Tucking on Physiological and Behavioural Responses to Pain among Infants Receiving Vaccination

Objective: To evaluate the effect of facilitated tucking on physiological and behavioural responses to painamong infants between experimental and control group before and after the IM vaccinationMethod: A quantitative approach with true experimental design and consecutive sampling technique wasused in this study. Researcher selected 100 infants up to the age of 6 month receiving IM vaccination inthe immunization clinic, AIMS, Kochi, and they are randomly assigned to control and experimental group.Demographic and clinical data was collected using structured interview schedule. Heart rate and SPO2was monitored 2 minutes prior to the vaccination and facilitated tucking was given to the experimentalgroup before and during the immunization and routine position was given to the control group, after thatbehavioural response was assessed by using neonatal infant pain scale and physiological response such asheart rate and SPO2 was assessed after 5 minutes.Result: The result showed that all the subjects in the control group had severe pain 100 %, whereas in theexperimental group 50 % of the subjects had moderate pain and 50% of them had mild pain. Also there wasa significant difference in the mean score of the physiological and behavioural response between the controland experimental group after the interventionConclusion: The study revealed that the Facilitated Tucking improves the emotional security and reducesthe pain perception. The nurse or care givers can effectively implement facilitative tucking for reducing painduring vaccination in any setting as it is a very simple technique

Glycoprotein D, a checkpoint inhibitor of early T-cell activation, to improve immunogenicity and efficacy of an HPV-16 vaccine in preclinical studies.

71 Background: CD8+ T cells can inhibit tumor progression, but their induction is hampered by the low immunogenicity of most tumor antigens. HSV-1 glycoprotein D (gD), when genetically expressed as a fusion protein with tumor antigens, serves as a checkpoint inhibitor of the B and T cell attenuator (BTLA)-herpes virus entry mediator (HVEM) pathway, which acts early during T cell activation. HSV-1 gD thereby augments antigen-driven CD8+ T cell responses. We describe the immunogenicity and efficacy of a chimpanzee adenoviral vector (AdC) vaccine containing a detoxified E7/E6/E5(AdC-gDE765dt) sequence of HPV-16 fused into gD. Methods: The frequency of HPV-16 E7-specific CD8+ T-cells was assessed by tetramer staining in C57/Bl6 mice 14 days after a single IM vaccination with AdC vectors encoding wild-type or mutant HPV-16 oncoproteins expressed within gD, a non-HVEM-binding form of gD or without gD. Efficacy was tested in a TC-1 tumor cell challenge model with mice receiving no treatment or a single IM vaccine injection 3 days after tumor cell transplantation. Mice were followed for 80 days. Results: The addition of gD increases HPV-16 E7-specific CD8+ T-cell frequencies approximately 10-fold. T cell responses are similar to AdC vaccines expressing wild-type or mutant oncoproteins within gD. All AdC-gDE765dt treated mice show delayed tumor progression after a single vaccination with 50% of animals remaining tumor-free at study completion. Conclusions: These results show that the addition of gD, an early checkpoint inhibitor, which acts locally at the site of T cell stimulation, to an HPV-16 vaccine markedly improves the vaccine’s immunogenicity and efficacy. AdC-gDE765dt is currently in GMP manufacture for Phase 1 investigation in HPV-16 infected patients.

Pre-travel health care attendance among migrant travellers visiting friends and relatives (VFR): a 10-year retrospective analysis

BackgroundTravellers visiting friends and relatives (VFR) define a specific population of travellers exposed to higher risks for health and safety than tourists. The aim of this study was to assess differentials in pre-travel health care in VFR travellers compared to other travellers.MethodsA retrospective cohort study was performed including attendees of the Travel Medicine Clinic of the Hospital Universitari de Bellvitge, Barcelona, Spain, between January 2007 and December 2017.ResultsOver the 10-year period, 47,022 subjects presented to the travel clinic for pre-travel health care, 13.7% of whom were VFR travellers. These showed higher rates of vaccination against yellow fever and meningococcus, but lower rates for hepatitis A, hepatitis B, influenza, rabies, cholera, polio, typhoid IM vaccine and tetanus vaccine boosters. Regarding malaria prevention measures, results highlighted that VFR travellers, when compared with tourists, were more likely to be prescribed with chemoprophylaxis, particularly with mefloquine, than with atovaquone/proguanil.ConclusionsFindings from this large-scale study indicated differences in vaccination rates and completion, as well as in chemoprophylaxis for malaria, between VFR and non-VFR travellers, fostering specific interventions for promoting adherence to pre-travel health advice among migrant travellers.

A Study to Assess the Effectiveness of Helfer Skin Tap Technique in Pain Reduction among Infants Undergoing Intramuscular Vaccination in Tertiary Care Setting, Coimbatore, Tamil Nadu, India

BACKGROUND: Pain is a common and disagreeable sensation for children and adult. Every child has his or her own perception of pain. Routine immunizations are the most frequent painful medical procedure during childhood. Health care professionals trying to provide vaccine to the infants with a less painful experience at their level of comfort, skin tapping (Helfer skin technique) is one of the methods which keeps the muscles relaxed and thus reduce pain while administering IM vaccination. OBJECTIVES: To assess the effectiveness of Helfer skin Tap technique on pain reduction among infants undergoing intramuscular vaccination and to associate the selected demographic variables with the pain level of infants during intramuscular vaccination among treatment and routine group. METHODOLOGY: The research design adopted was quantitative research approach, quasi experimental, time series design. The study was conducted in pediatric vaccination clinic in PSG Hospitals, Peelamedu, Coimbatore. Purposive sampling technique used to select the eligible population. Simple random sampling technique was used to allocate the 60 study subjects to treatment and routine group which comprised 30 in each group. FLACC pain scale was used to assess the vaccination pain among infants undergoing intramuscular vaccination. Pre assessment was done 5minutes prior to the administration of IM vaccination for both groups and Helfer skin tapping was given to infants of treatment group. During Intramuscular vaccination the pain assessment was done in both the groups and post test level of pain was assessed at 1, 5, and at 10 minutes using FLACC pain scale. RESULTS: The study findings high lights that during pre assessment in treatment group 27 (90%) infants were relaxed and comfortable & in routine group 23 (76.77%) infants were relaxed and comfortable. During vaccination in treatment group 19 (63.33%) infants experienced moderate pain where as in routine group 27 (90%) infants experienced severe pain. After the vaccination at 1st minute the treatment group 18 (60%) infants had moderate pain where as the routine group 12 (40%) infants had severe pain. Five minutes after the vaccination in treatment group 15 (50%) infants had mild pain where as in routine group 14 (46.6%) infants had moderate pain. Ten minutes After the vaccination in treatment group 26 (86.6%) infants relaxed and comfortable where as in routine group 24 (80%) infants experienced mild pain. There was a significant reduction in pain perception among infants in treatment group during vaccination (5.30±1.74, p < 0.001), after the vaccination at 1st minute (3.93±1.51, p < 0.001) and 5thminute (2.03±1.69, p < 0.001) and at 10th minute (0.39±0.79, p < 0.001) than the routine group. Female infants 15 (50%) experienced severe pain compared with male infants 12(40%) in routine group (χ2=6.44, P < 0.01).For other demographic variables there was no association in treatment and routine group. CONCLUSION: Helfer skin tap technique was effective in reducing the IM vaccination pain during and after the vaccination.

The genetic adjuvant IL-12 enhances the protective efficacy of a DNA vaccine for Venezuelan equine encephalitis virus delivered by intramuscular injection in mice

We have previously shown that DNA vaccines expressing codon-optimized alphavirus envelope glycoprotein genes protect both mice and non-human primates from viral challenge when delivered by intramuscular electroporation (IM-EP). To determine if we could achieve equivalent immunogenicity and protective efficacy in the absence of electroporation, we co-delivered our Venezuelan equine encephalitis virus (VEEV) DNA vaccine with DNA plasmids expressing genetic adjuvants designed to augment immune responses. We tested the Th1-inducing cytokine IL-12 as well as the granulocyte growth factor GM-CSF, both of which have demonstrated significant adjuvant effect when included in clinical DNA vaccine formulations. Additionally, as multiple reports have described the necessity of IFN-αβ in DNA vaccine immunogenicity, we tested vaccine plasmids encoding a potent stimulator of the IFN-αβ pathway. Our data suggest that IM vaccination of mice with plasmid DNA encoding genetic adjuvants enhances VEEV vaccine immunogenicity, resulting in improved T cell responses, as well as skewing of the anti-VEEV IgG antibody isotype. Additionally, IM vaccination of VEEV DNA vaccine and IL-12 provided complete protection against aerosol VEEV challenge. Overall, our data suggest that co-delivery of genetic adjuvants with alphavirus DNA vaccines using IM delivery can influence the type of immune response obtained and provide comparable protective immunity to that achieved by IM-EP delivery of the vaccine without adjuvants.

P-C3 A Modified Vaccinia Ankara vector expressing Lassa virus-like particles (MVA-LasVLP) protects mice from lethal challenge with a Lassa-Mopeia reassortant virus

The Lassa-endemic areas of West Africa, including the embattled areas of northern Nigeria have been experiencing more frequent outbreaks of Lassa fever (early 2016 through the summer of 2017). Consequently an international effort has been launched to produce a Lassa vaccine, including a test of the MVA-LASV-VLP (GEO-LM02). The MVA vector has been developed by Dr. B. Moss' lab at NIH in collaboration with GeoVax to deliver a variety of vaccine antigens. The GeoVAX-MVA-HIV-VLP has been used in human trials involving more than 500 participants, it has the capacity to express large recombinant antigens, it elicits robust T and B cell responses, and is relatively safe due to its inability to replicate in mammalian cells. Of all the current Lassa vaccine candidates, GEO-LM02 is the only one that produces VLP in vivo. Our experiments tested the optimum route of vaccination. We used young CBA/J mice that were challenged 2 weeks after vaccination with an intracerebral (ic) dose of a Lassa-Mopeia reassortant virus. Mice were given a single dose of GEO-LM02 by subcutaneous (sc), intraperitoneal (ip), and intramuscular (im) routes. One hundred percent of those given im vaccine survived the lethal challenge, whereas the other routes were slightly less protective. All unvaccinated mice died within 8d post challenge. A second round of experiments confirmed the previous results and demonstrated a robust cell-mediated immunity after a single dose im vaccination. Again 100% of the un-vaccinated mice succumbed to lethal challenge and experienced erosion of their blood-brain-barrier. Subsequent experiments will test the durability of immunity in surviving mice.

Inactivated rotavirus vaccine by parenteral administration induces mucosal immunity in mice

To improve the safety and efficacy of oral rotavirus vaccines, we developed an inactivated rotavirus vaccine (IRV) for parenteral administration. Since it remains unknown whether parenteral vaccination can induce mucosal immunity, we performed a comprehensive assessment of immune responses to IRV in mice with an adjuvant-free dissolving polymer MN patch or by alum-adjuvanted IM injection. We demonstrated that IRV induced the expression of the gut homing receptor LPAM-1 on T and B cells in spleen and mLN of vaccinated mice. MN patch IRV vaccination induced a slight Th1 phenotype while IM vaccination induced a balanced Th1/Th2 phenotype. In addition, a dose-sparing effect was seen for rotavirus-specific serum IgG and neutralizing activity for both vaccination routes. Our study is the first to show that parenterally administered IRV can induce mucosal immunity in the gut, in addition to strong serum antibody response, and is a promising candidate vaccine in achieving global immunization against rotavirus.

Mucosal delivery of a vectored RSV vaccine is safe and elicits protective immunity in rodents and nonhuman primates

Respiratory Syncytial Virus (RSV) is a leading cause of severe respiratory disease in infants and the elderly. No vaccine is presently available to address this major unmet medical need. We generated a new genetic vaccine based on chimpanzee Adenovirus (PanAd3-RSV) and Modified Vaccinia Ankara RSV (MVA-RSV) encoding the F, N, and M2-1 proteins of RSV, for the induction of neutralizing antibodies and broad cellular immunity. Because RSV infection is restricted to the respiratory tract, we compared intranasal (IN) and intramuscular (M) administration for safety, immunogenicity, and efficacy in different species. A single IN or IM vaccination completely protected BALB/c mice and cotton rats against RSV replication in the lungs. However, only IN administration could prevent infection in the upper respiratory tract. IM vaccination with MVA-RSV also protected cotton rats from lower respiratory tract infection in the absence of detectable neutralizing antibodies. Heterologous prime boost with PanAd3-RSV and MVA-RSV elicited high neutralizing antibody titers and broad T-cell responses in nonhuman primates. In addition, animals primed in the nose developed mucosal IgA against the F protein. In conclusion, we have shown that our vectored RSV vaccine induces potent cellular and humoral responses in a primate model, providing strong support for clinical testing.

Reproductive, productivity, and mortality outcomes in late-gestation gilts and their litters following simulation of inadvertent exposure to a modified-live vaccine strain of porcine reproductive and respiratory syndrome (PRRS) virus

The study evaluated the safety of a modified live-virus (MLV) porcine reproductive and respiratory syndrome (PRRS) vaccine in susceptible, pregnant gilts. To simulate inadvertent exposure secondary to postvaccination shedding of PRRS-MLV, seronegative gilts (n=51) were exposed by IM vaccination at 90 days of gestation. Vaccinated and nonvaccinated, seronegative control gilts (n=25) were maintained in separate facilities. The PRRS-MLV vaccine was given in a 2mL dose on day 0. On day 7 all vaccinated gilts were PRRSV-PCR-positive for PRRSV and had responded serologically as determined by an ELISA. All control gilts remained PRRSV-PCR- and ELISA-negative throughout the study. Abortions did not occur in gilts from either group. The difference between vaccinated and control gilts in average number of piglets per litter (12.43 and 12.16, respectively), number of live births per litter (11.21 and 11.54), and mean piglet birth weight (3.22 and 3.26 lbs) were not significantly different. Piglets in the control group had significantly greater average daily gain versus piglets from vaccinated gilts (0.52 vs. 0.46 lbs, P<0.0001). Preweaning mortality was significantly greater (P=0.0023) in piglets from the vaccinated gilts (19.7% vs. 10.9%). A single gilt accounted for 18.2% of stillbirths in the vaccinated group. Air samples were borderline PRRSV-PCR-positive for PRRSV on days 29 and 32, after more than 98% of gilts had farrowed. Results demonstrated that vaccination of pregnant gilts at the time of peak fetal susceptibility was non-abortigenic and that the PRRS-MLV agent did not significantly affect reproductive outcomes. Lower ADG in piglets from vaccinated gilts may be due to PRRS-MLV viremia following transplacental or post-farrowing exposure. Air sampling results indicated that environmental contamination with PRRS-MLV shed from vaccinated gilts was minimal.

Stability of vaccine induced Th2 cells following intranasal infection with group A streptococcus (P4258)

Abstract Group A streptococcus (GAS) naturally colonizes the human pharynx and can cause pharyngitis. We have found that intranasal administration (i.n.) of GAS elicits a Th17 response in mice; in contrast, intramuscular (i.m.) injection of recombinant GAS protein vaccines elicits a Th2 response. The influence of GAS infection on the vaccination-induced Th2 population was assessed using IL-4 reporter mice (4get and KN2) immunized with a GAS protein vaccine plus alum. Vaccination caused expansion of IL-4+ T helper cells which did not express IL-17A. Purified GFP+IL-4+ Thy1.1+ CD4+ T cells from vaccinated 4get mice were adoptively transferred to Thy1.2+ congenic recipients to evaluate their response to subsequent GAS infections. Recipient mice were infected i.n. with GAS and cytokine profiles of transferred cells were determined. In 5 of 6 recipient mice, GFP+Thy1.1+ cells retained their original Th2 phenotype and did not express IL-17A. In the sixth mouse, 8.6% of Thy1.1+ cells expressed IL-17A after exposure to GAS. As expected, endogenous Thy1.2+ cells from infected recipients expressed IL-17A. Thus, im vaccination primarily induced Th2 cells, and most cells were terminally differentiated and unable to develop the capacity to express IL-17A upon subsequent mucosal exposure to GAS. Thus vaccination with recombinant GAS proteins is unlikely to create a reservoir of GAS-specific T cells that can become polarized toward a Th17 response upon GAS infection.

The Hepatitis B Vaccine and Celiac Disease: More Lights Than Shadows?

Dear Editor, Actually, in literature, it is known that HLA-DQ2 haplotype is over-represented in celiac population and since both HBsAg protein fragments and gliadin peptides bind to HLA-DQ2 molecules; their competition may favors a defective antibody response against the recombinant HBsAg vaccine in active celiac disease (1). On the other hand, some studies demonstrate that in celiac individuals, the gluten intake at the time of vaccination influences the vaccine-induced immune response (2). All these hypotheses are still argument of debate because the non-responsiveness of celiac patients to the HBV vaccine remains a significant public health problem, although there is no convinced evidence that patients with viral hepatitis B show an increased risk of celiac disease (3). It would be important to assess the possible vaccination strategy in order to reduce this potential “healthy-reservoir” of infection. Regarding to this, new vaccination strategies for celiac patients were proposed in literature: the first one was the use of booster doses of HBV vaccine by intra-muscular route (IM), using higher doses or a higher number of injections after a gluten free diet; the second was the performance of vaccine boosters by intra-dermal route (ID) (4). The rational of the second strategy is that as opposed to intramuscular vaccination (IM), which relies on a T-cell mediated response, the vaccine directly introduced into the skin activates a dendritic-cell-mediated immune response, using a lower dose of antigen (5). The comparison of both routes suggests that both ID and IM routes are effective options to administer a booster dose of HBV vaccine in celiac patients although the ID route seems to result in a higher percentage of patients with an anti-HBs titer > 1000 IU/L (6). A recent retrospective cost-benefit analysis of ID hepatitis B vaccination reported a cost reduction exceeding 50% in comparison with a standard IM vaccine regimen (7). In fact the increase of anti-HBs antibodies is satisfactory after ID injection in all patients, a lower dose of the vaccine can be used, the cellular immune responsiveness to HBsAg can be easily assessed by the development of a skin reaction at the injection site (8) and thanks to the setup of this reaction there is no need of venous withdraws to test the serum anti-HBs concentration after the booster dose. On this debate, few shadows remains unsolved, because it is still not clear if celiac non-responders show an immunity energy since birth and do not respond since the first dose of vaccination or they lose their antibody protection with the flow of time, as physiologically happens in normal people, even if in a shorter period of time. Consequently, two subgroups of non-responders should be classified: the first group is the pure non-responders, that are celiac patients with a non-responsiveness since the first booster dose of HBV vaccine, and the second is the group of patients that lost their memory after a period of time after the vaccine injection. On this regard, in literature it is also demonstrated that immunological memory persists more than 10 years after the immunization of infants and adolescents with a primary course of vaccination (9) and there is general consensus that successfully vaccinated people who have lost their antibodies years after primary vaccination usually show a rapid anamnestic response when boosted (9). This means that the immunological memory for HBsAg can outlast antibody detection, providing long-term protection against the disease and the development of the carrier state. Therefore, until new data shed light on this issue good advice seems to be: 1) In consideration of the possible relationship between anti-HBs titers and compliance with gluten free diet (GFD), they should be always revaccinated after the decrease of specific celiac antibodies, which usually occurs after about 1 year of a strict GFD in order to maintain a high level of immunization. 2) After all, patients with CD should always receive a booster dose of vaccine every 10 years independently by their status of “pure” unresponsiveness. 3) HBV vaccine by intradermal route should be preferred instead of intramuscular route because of the use of lower doses of vaccine and the possibility to assess cellular immune responsiveness to HBsAg by the development of a skin reaction at the injection site (8).

Dose sparing intradermal trivalent influenza (2010/2011) vaccination overcomes reduced immunogenicity of the 2009 H1N1 strain

BackgroundWe hypothesized that low dose intradermal vaccination of the trivalent influenza vaccine (TIV) delivered by the MicronJet600™ (NanoPass Technologies, Israel) would be non-inferior to the full dose intramuscular and mid dose Intanza® vaccination in the elderly and the chronically ill adults. MethodsWe performed a prospective randomized trial on elderly and chronically ill adults. Subjects were randomly assigned into 4 groups. Groups ID3 and ID9 received reduced dose ID TIV (3μg and 9μg of hemagglutinin (HA) per strain respectively) delivered by MicronJet600™ (NanoPass Technologies, Israel). Group INT9 received reduced dose ID TIV (9μg) delivered by Becton Dickinson's Soluvia™ device (Intanza®9, Sanofi-Pasteur, France). Control group IM15 received a full dose IM TIV (15μg). We measured antibody titers by hemagglutination inhibition (HAI) and microneutralization (MN) assays at baseline and day 21. ResultsBaseline characteristics for all groups were similar (group and sample sizes: ID3=63; ID9=68; INT9=65; and IM15=66). At day 21 post vaccination, the GMT ratio and the seroconversion rates difference for all three strains of the ID vaccine groups were non-inferior to the IM vaccine group. The seroconversion rate, seroprotection rate, and the GMT of the H1N1 strains by HAI and MN assays were significantly higher in the ID groups compared with the full dose IM vaccine group. The seroconversion rates of the H3N2 strain by HAI assay were also significantly higher in the ID groups when compared with the full dose IM group. Direct comparison among the three ID groups showed no significant differences. No serious adverse events related to vaccination were reported. ConclusionDose-sparing ID TIV can overcome reduced immunogenicity of the H1N1 strain, and according to some measures, for the H3N2 strain. At risk subjects indicated for the TIV should be considered for intradermal immunization to compensate for reduced immunogenicity.

Intanza® 15 mcg intradermal influenza vaccine elicits cross-reactive antibody responses against heterologous A(H3N2) influenza viruses

The aim of the present study was to explore the ability of Intanza® 15μg, the intradermal (ID) trivalent inactivated split-virion influenza vaccine containing 15μg hemagglutinin per strain, to enhance the antibody responses against heterologous circulating H3N2 strains in adults 60 years and older. During the 2006–2007 influenza season, subjects aged 60 years or older were randomly assigned to receive one dose of ID or an intramuscular (IM, Vaxigrip®) influenza vaccine, which contained the reassortant A/Wisconsin/67/05(H3N2) strain as the H3N2 component. Antibody responses were assessed against the homologous vaccine strain, against the A/Brisbane/10/07(H3N2) reassortant strain and against four heterologous H3N2 field isolates (A/Genoa/62/05(H3N2), A/Genoa/3/07(H3N2), A/Genoa/2/07(H3N2), A/Genoa/3/06(H3N2)). The viruses tested belonged to three different clades that were closely related antigenically to A/California/7/04(H3N2), A/Nepal/921/06(H3N2) and A/Brisbane/10/07(H3N2). Antibody responses to these viruses were measured in 25 subjects per group using both haemagglutination inhibition (HI) and neutralization (NT) assays.At least one Committee for Medicinal Products for Human Use (CHMP) immunogenicity criteria for vaccine approval in the elderly was reached by both vaccines against all the viruses used in the study. All three CHMP criteria were reached against A/California/7/04(H3N2)-like, A/Nepal/921/06(H3N2)-like and A/Brisbane/10/07(H3N2)-like viruses by Intanza® 15μg ID vaccine, while IM vaccination did not meet seroprotection criteria against circulating A/Nepal/921/06(H3N2)-like and A/Brisbane/10/07(H3N2)-like viruses or seroconversion criteria against A/Brisbane/10/07(H3N2)-like viruses.Post-vaccination HI titer, seroconversion, and seroprotection rates were higher against all viruses in subjects who received Intanza® 15μg. The superiority of the seroprotection rate against the A/Nepal/921/06(H3N2)-like strain attained statistical significance despite the small sample size.Upon Beyer correction for pre-vaccination status, post-immunization HI titers against A/California/7/04(H3N2)-like and A/Brisbane/10/07(H3N2)-like strains and NT post-immunization titers against A/Wisconsin/67/05(H3N2), A/California/7/04(H3N2)-like, A/Brisbane/10/07(H3N2)-like strains were significantly higher in subjects immunized with Intanza® 15μg than in individuals receiving IM vaccine.This study, although limited in the size of study population, demonstrated the broader immune response elicited by an ID influenza vaccine vs. a standard IM influenza vaccine against heterologous viruses including field isolates.

Safety and efficacy of a xenogeneic DNA vaccine encoding for human tyrosinase as adjunctive treatment for oral malignant melanoma in dogs following surgical excision of the primary tumor

To evaluate the safety and efficacy of a vaccine containing plasmid DNA with an insert encoding human tyrosinase (ie, huTyr vaccine) as adjunctive treatment for oral malignant melanoma (MM) in dogs. 111 dogs (58 prospectively enrolled in a multicenter clinical trial and 53 historical controls) with stage II or III oral MM (modified World Health Organization staging scale, I to IV) in which locoregional disease control was achieved. 58 dogs received an initial series of 4 injections of huTyr vaccine (102 μg of DNA/injection) administered transdermally by use of a needle-free IM vaccination device. Dogs were monitored for adverse reactions. Surviving dogs received booster injections at 6-month intervals thereafter. Survival time for vaccinates was compared with that of historical control dogs via Kaplan-Meier survival analysis for the outcome of death. Kaplan-Meier analysis of survival time until death attributable to MM was determined to be significantly improved for dogs that received the huTyr vaccine, compared with that of historical controls. However, median survival time could not be determined for vaccinates because < 50% died of MM before the end of the observation period. No systemic reactions requiring veterinary intervention were associated with vaccination. Local reactions were primarily limited to acute wheal or hematoma formation, mild signs of pain at the injection site, and postvaccination bruising. Results support the safety and efficacy of the huTyr DNA vaccine in dogs as adjunctive treatment for oral MM. Response to DNA vaccination in dogs with oral MM may be useful in development of plasmid DNA vaccination protocols for human patients with similar disease.

Nonclinical biodistribution, integration, and toxicology evaluations of an H5N1 pandemic influenza plasmid DNA vaccine formulated with Vaxfectin®

Vaxfectin® is a lipid-based adjuvant initially developed for use with plasmid DNA (pDNA) vaccines. Here we present detailed nonclinical assessments performed prior to Vaxfectin®’s first-in-man use, as an adjuvant in the H5N1 influenza vaccine VCL-IPT1. Following IM delivery to rabbits, VCL-IPT1 pDNA localized primarily to injection sites, where levels steadily declined over the 2 months examined. Risk of pDNA integration into genomic DNA was negligible. Toxicology studies in rabbits revealed mild inflammatory/immune responses at injection sites characteristic of IM vaccine delivery; Vaxfectin® directly contributed to these responses. These data support clinical development of H5N1 pDNA vaccines, and also present an encouraging profile for further development of Vaxfectin® as an adjuvant for vaccines in general.

Oral and Parenteral Immunization of Chickens (Gallus gallus) Against West Nile Virus with Recombinant Envelope Protein

West Nile virus (WNV) causes morbidity and mortality in humans, horses, and in more than 315 bird species in North America. Currently approved WNV vaccines are designed for parenteral administration and, as yet, no effectiveoral WNV vaccines have been developed. WNV envelope (E) protein is a highly antigenic protein that elicits the majority ofvirus-neutralizing antibodies during a WNV immune response. Leghorn chickens were given three vaccinations (each 2 wk apart) of E proteinorally (20 microg or 100 microg/dose), of E protein intramuscularly (IM, 20 microg/dose), or of adjuvant only (control group) followed by a WNV challenge. Viremias were measured post-WNV infection, and three new enzyme-linked immunosorbent assays were developed for quantifying IgM, IgY, and IgA-mediated immune response of birds following WNV infection. WNV viremia levelswere significantly lower in the IM group than in both oral groups and the control group. Total WNV E protein-specific IgY production w assignificantly greater, and WNV nonstructural 1-specific IgY w as significantly less, in the IM group compared to all other treatment groups.The results of this study indicate that IM vaccination of chickens with E protein is protective against WNV infection and results in a significantly different antibody production profile as compared to both orally vaccinated and nonvaccinated birds.

Rapid immunity to vaccination with woodchuck hepatitis virus surface antigen using cationic liposome–DNA complexes as adjuvant

Complexes of cationic liposomes and non-coding DNA (CLDC) have shown promise as vaccine adjuvant. Using the woodchuck animal model of hepatitis B virus (HBV) infection, the immunogenic effects of CLDC were evaluated following vaccination with three doses of woodchuck hepatitis virus surface antigen (WHsAg) adjuvanted with either CLDC or conventional alum and administered intramuscularly (im) or subcutaneously (sc). IM vaccination with WHsAg and CLDC elicited antibodies earlier, in more woodchucks, and with higher titers than WHsAg and alum. After two vaccine doses, antibody titers were higher following im than sc administration. Woodchucks administered two vaccine doses sc received the third vaccine dose im, and antibody responses reached titers comparable to those elicited by im administration. Following the second vaccine dose, im vaccination with WHsAg and CLDC induced T cell responses to WHsAg and selected WHs peptides and expression of the leukocyte surface marker CD8 and of the Th1 cytokines interferon-gamma and tumor necrosis factor alpha in woodchucks. T cell responses and CD8/cytokine expression were diminished in woodchucks from the other groups suggesting that this vaccine regimen induced a skew toward Th1 immune responses. The present study in woodchucks demonstrates that CLDC-adjuvanted WHsAg vaccine administered im resulted in a more rapid induction of humoral and cellular immune responses compared to conventional, alum-adjuvanted WHsAg vaccine. While less rapid, the immune responses following sc administration can prime the im immune responses. This adjuvant activity of CLDC over alum may be beneficial for therapeutic vaccination in chronic HBV infection.