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Introduction: The prevalence of influenza epidemics and direct transmission of the emerged avian virus strains to humans have highlighted the necessity of improving the management programs against this disease. The aim of this study was to evaluate the biological adjuvant effect of hemokinin-1 (HK-1) on enhancing the immune response induced by the recombinant influenza vaccine based on the Nucleoprotein protein (NP) of the H1N1 influenza virus. Materials & Methods: In this experimental study, a total of 40 six-week-old female BALB/c mice were divided into two control groups (5 mice per group) and three treatment groups (10 mice per group). The control groups received normal saline and HK-1 oligonucleotide adjuvant. On the other hand, the treatment groups received NP recombinant protein (twice), NP protein with HK-1 (once), as well as NP protein with HK-1 (twice). Based on the grouping, 0.1 ml of each sample was injected into the quadriceps femoris muscle of the mice. The treatment groups received a 1:10 (v/v) ratio of the NP protein and HK-1. The serum samples were collected prior to primary and reminder vaccinations in defined intervals. The immune responses were analyzed using enzyme-linked immunosorbent and lymphocyte proliferation assays. Ethics code: RSVRI.REC.98.010 Findings: The rise of the anti-influenza antibody in immunized mice with recombinant NP-based vaccine received HK-1 adjuvant was significant, compared to that in the control group (P

Background: Problems of live and inactivated influenza vaccines such as, increasing emerge and re-emerge viruses with high human mortality, current epidemics of influenza and direct transmission of avian viruses to human, affect the vaccination program. DNA vaccines as third generation of vaccines is specially considered for control of influenza in human and poultry. The main advantage of these vaccines is humoral and cellular immune responses and broad spectrum of using these vaccines for control of circulating strains of influenza. In this study the conserved fragment of HA2 to form of DNA vaccine was designed to induce immunity against influenza viruses and its heterologous protective immunity against these viruses was evaluated. Methods: The experimental study was performed in Razi Vaccine and Serum Research Institute from December 2014 to July 2015 in Iran. The HA2 was cloned into pcDNA3.1 to assess the HA2 DNA vaccine and mice were immunized with the generated constructs in a DNA prime-DNA boost regimen in 4 groups. The humoral immune responses were analyzed at defined intervals by VN tests. The safety of the vaccine was evaluated by daily inspection and histopathological examination. For evaluation of cellular immunity, proliferation assay was used. Results: The antibody titre and cellular immunity of immunized mice was significantly higher than control group for two serotypes and the highest responses was in the group with two-time boosting (P

Background: In the last decade due to emerge and remerge of influenza viruses, quality improvement of vaccines to increase immune responses in target populations have been more necessary. The potential of biologic adjuvant to stimulate and induce immune system is the basis of modern researches in prevention and controlling program of infectious diseases. In this study, the effect of the coding sequence of cellular Myxovirus resistance (Mx) protein as a biological adjuvant for inducing humoral immune response against influenza virus was investigated. Methods: The experimental study was performed on Balb/c mice in Razi Vaccine and Serum Research Institute from June to November 2014. Three conserved motifs of Mx were selected following sequence alignment between human, mouse and bird species. Potential of the motifs for stimulation immune responses against influenza virus were evaluated using in silico analysis. Based on the immune informatics data Mx1 sequence was the best immune inducer and cloned into pcDNA3.1 vector. Then formulated with inactivated H9N2 influenza antigen as adjuvant and injected to mice groups. The sera of vaccinated mice were collected prior to priming and boosting injections and also at defined weeks and analyzed with serological assays. Histopathological examination was done for evaluation of the vaccine and adjuvant safety. Results: The mean weight of the Balb/c mice in all control and treatment groups was similar and ranged from 21 to 37 gr (P= 0.05). The difference in increasing antibody titers against influenza virus in immunized mice who received Mx1-adjuvanted vaccine especially in second boosting was significant (P= 0.01) compared to the vaccine alone group. More than 78% of the immunized mice receiving two-time boosting have the mean antibody titer of >6 (Log2) which was higher (P= 0.001) comparing to the mice with one booster injection. Conclusion: These data revealed that Mx1 as biological adjuvant was able to increase antibody titer and induction memory immune responses against influenza immunization without causing any side effects.