OBJECTIVE: To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. METHODS: Mice were immunized intranasally with PBS (negative control), or H3N2 split vaccine (3 μg/mouse) alone, or CTA1-DD (5 μg/mouse) alone, or H3N2 split vaccine (3 μg/mouse) plus CTA1-DD (5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine (3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured. RESULTS: H3N2 split vaccine formulated with CTA1-DD could elicit higher IgM, IgG and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory IgA titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus. CONCLUSION CTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.
Adjuvants, Immunologic ; Administration, Intranasal ; Animals ; Cholera Toxin ; Female ; Immunity, Humoral ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza Vaccines ; Mice, Inbred BALB C ; Nasal Mucosa ; immunology ; Random Allocation ; Recombinant Fusion Proteins

Swine influenza viruses (SwIVs) cause considerable morbidity and mortality in domestic pigs, resulting in a significant economic burden. Moreover, pigs have been considered to be a possible mixing vessel in which novel strains loom. Here, we developed and evaluated a novel M2e-multiple antigenic peptide (M2e-MAP) as a supplemental antigen for inactivated H3N2 vaccine to provide cross-protection against two main subtypes of SwIVs, H1N1 and H3N2. The novel tetra-branched MAP was constructed by fusing four copies of M2e to one copy of foreign T helper cell epitopes. A high-yield reassortant H3N2 virus was generated by plasmid based reverse genetics. The efficacy of the novel H3N2 inactivated vaccines with or without M2e-MAP supplementation was evaluated in a mouse model. M2e-MAP conjugated vaccine induced strong antibody responses in mice. Complete protection against the heterologous swine H1N1 virus was observed in mice vaccinated with M2e-MAP combined vaccine. Moreover, this novel peptide confers protection against lethal challenge of A/Puerto Rico/8/34 (H1N1). Taken together, our results suggest the combined immunization of reassortant inactivated H3N2 vaccine and the novel M2e-MAP provided cross-protection against swine and human viruses and may serve as a promising approach for influenza vaccine development.
Animals ; Antibodies, Viral/blood ; Antigens, Viral/genetics/*immunology ; Body Weight ; Cross Protection/*immunology ; Disease Models, Animal ; Epitopes, T-Lymphocyte/genetics/immunology ; Female ; Influenza A Virus, H3N2 Subtype/genetics/*immunology ; Influenza Vaccines/*immunology ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections/*immunology/mortality/pathology/prevention & control ; Peptides/genetics/*immunology ; Random Allocation ; Survival Analysis ; Vaccines, Synthetic/immunology ; Virus Replication

Influenza A virus is an enveloped virus that belongs to the Orthomyxoviridae family. It has 8 negative RNA segments that encode 16 viral proteins. The viral polymerase consists of 3 proteins (PB 1, PB2 and PA) which plays an important role in the transcription and replication of the influenza A virus. Polymerase basic protein 1 (PB 1) is a critical member of viral polymerase complex. In order to further study the function of PB1, we need to prepare the PB1 antibody with good quality. Therefore, we amplified PB1 conserved region (nt1648-2265) by PCR and cloned it into pET-30a vector, and transformed into Escherichia coli BL2 1. The expression of His tagged PB 1 protein was induced by IPTG, and His-PB 1 proteins were purified by Ni-NTA resin. For preparation of PB 1 protein antiserum, rabbits were immunized with His-PB 1 fusion protein 3 times. Then the titer of PB 1 polyclonal antibody was measured by indirect ELISA. The antibody was purified by membrane affinity purification and subjected to immunoblotting analysis. Data showed that PB1 antibody can recognize PB 1 protein from WSN virus infected or pCMV FLAG-PB 1 transfected cells. Meanwhile, PB 1 antibody can also recognize specifically other subtype strains of influenza A virus such as H9N2 and H3N2. PB 1 polyclonal antibody we generated will be a useful tool to study the biological function of PB1.
Animals ; Antibodies, Viral ; biosynthesis ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; metabolism ; Genetic Vectors ; Influenza A Virus, H3N2 Subtype ; Influenza A Virus, H9N2 Subtype ; Plasmids ; Rabbits ; Viral Proteins ; immunology

To analyze the antigenic and genetic characteristics of the influenza A (H3N2) virus in mainland China during the surveillance year of 2013-2014, the antigenic characteristics of H3N2 virus were analyzed using reference ferret anti-sera. The nucleotide sequences of the viruses were determined by Sanger dideoxy sequencing, phylogenetic trees were constructed with the neighbor-joining method, and the genetic characteristics of the viruses were determined in comparison to current vaccine strains. The results showed that most of the H3N2 viruses were antigenically closely related to the A/Victoria/361/2011 vaccine strain cell-propagated prototype virus (99.6%). Using the A/Texas/50/2012 egg isolate as the reference antigen, 15.1% of the viruses were found to be closely antigenically related to it, while 11.9% of strains were closely antigenically related to the egg-propagated epidemic strain, A/Shanghai-Changning/1507/2012. Phylogenetic analysis of HA genes indicated that the A(H3N2) viruses in this surveillance year were in the same clade, but no drug resistant mutation was identified in the NA genes. During the 2013-2014 influenza surveillance year, no significant genetic change was detected in either the HA or NA genes of the A(H3N2) viruses, while significant mutations were found in egg isolates resulting from their adaptation during propagation in eggs. The antigenic and genetic changes should be investigated in a timely manner to enable the selection of an appropriate vaccine strain in China.
Animals ; Antigenic Variation ; Base Sequence ; Chick Embryo ; China ; Genetic Variation ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; immunology ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; immunology ; isolation & purification ; Influenza, Human ; virology ; Molecular Sequence Data ; Mutation ; Phylogeny

Adult ; Antibodies, Viral ; blood ; immunology ; Cross Reactions ; Hemagglutinin Glycoproteins, Influenza Virus ; immunology ; Humans ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; immunology ; Orthomyxoviridae ; immunology ; Seasons ; Vaccination

Novel reassortant H3N2 swine influenza viruses (SwIV) with the matrix gene from the 2009 H1N1 pandemic virus have been isolated in many countries as well as during outbreaks in multiple states in the United States, indicating that H3N2 SwIV might be a potential threat to public health. Since southern China is the world's largest producer of pigs, efficient vaccines should be developed to prevent pigs from acquiring H3N2 subtype SwIV infections, and thus limit the possibility of SwIV infection at agricultural fairs. In this study, a high-growth reassortant virus (GD/PR8) was generated by plasmid-based reverse genetics and tested as a candidate inactivated vaccine. The protective efficacy of this vaccine was evaluated in mice by challenging them with another H3N2 SwIV isolate [A/Swine/Heilongjiang/1/05 (H3N2) (HLJ/05)]. Prime and booster inoculation with GD/PR8 vaccine yielded high-titer serum hemagglutination inhibiting antibodies and IgG antibodies. Complete protection of mice against H3N2 SwIV was observed, with significantly reduced lung lesion and viral loads in vaccine-inoculated mice relative to mock-vaccinated controls. These results suggest that the GD/PR8 vaccine may serve as a promising candidate for rapid intervention of H3N2 SwIV outbreaks in China.
Animals ; Female ; Influenza A Virus, H3N2 Subtype/*genetics/immunology ; Influenza Vaccines/genetics/immunology/*therapeutic use ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections/immunology/*prevention & control/virology ; Reassortant Viruses/genetics/immunology ; Reverse Genetics/methods/*veterinary ; Swine ; Swine Diseases/immunology/*prevention & control/virology ; Vaccines, Inactivated ; Virus Replication

The molecular characterization and phylogenetic analysis of hemagglutinin (HA) genes of human influenza H3N2 viruses in Guangdong, China from 2007 to 2010 were studied in this study. By space-time sampling of strains, the HA genes of H3N2 strains from Guangdong were sequenced and searched from Internet, and then the variation and evolution of HA genes were conducted by Lasergene 7.1 and Mega 5.05 and evolutionary rates were analyzed by epidemiological data. The phylogenetic tree was established by alignment of 17 Guangdong strains and 26 global reference strains. Ks rates and Ka rates of HA genes were 2.06 x 10(-3)-2.23 x 10(-3) Nt/Year and 1.05 x 10(-3)-1.21 x 10(3) Nt/Year during 2007-2010, while the velocity of HA1 evolution of Ka was 3. 13 times than that of HA2 evolution. Compared with HA of vaccine strain A/Perth/16/2009, the genetic homologies of Guangdong strains in 2009 reached to 98.8%-99.7% and of Guangdong strains in 2010 reached to 98.0%-98.4%. There were some amino acid substitutions in five epitope regions of HA1 during 2007-2010, especially in B region (N160K) and D region (K174R/N); the K189E/N/Q and T228A in RBS (receptor-binding site) occurred in 2010 as two glycoproteins sites substituted impacted on the HA1 antigenicity. The antigenicity of epidemic H3N2 strains in 2010 was to some degree different that of the vaccine strain A/ Perth/16/2009. According to that there were variations of B and D epitopes and two sites of RBS and two glycoprotein in Guangdong H3N2 HA1 genes, WHO/ CDC should recommend new representative strains during 2011-2012 influenza seasons if H3N2 HA genes further evolve in the near future.
Amino Acid Substitution ; China ; Disulfides ; chemistry ; Epitopes ; genetics ; Evolution, Molecular ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; Mutation ; Phylogeny

To understand the HA1 genetic variation characterization of influenza H3N2 virus isolates in Zhu-hai during 2008-2009, we selected 20 of H3N2 Influenza strains cultured in MDCK cell. Viral RNAs were extracted and amplified by using RT-PCR. The amplified products were purified after identified by gel electrophoresis and then the nucleotide sequences of the amplicons were determined. The results were analyzed by the software ClustalX and MEGA4. 1. When compared with the amino acid sequences of the epitopes of HA1 district of H3N2 influenza vaccine recommended by WHO in 2008, changes were found in those of H3N2 influenza strains in Zhuhai in 2008: K140I in all of H3N2 influenza strains, L157S in 08-0343 and 08-0677, K158R in 08-0466, 08-0620 and 08-0667, K173E in 08-0466 and 08-0620, K173N in 08-0667, and I192T in 08-0667. The epitopes of HA1 district of H3N2 influenza strains in Zhuhai in 2009 are different from that of H3N2 influenza vaccine during the same time: K173Q and P194L occur in all of H3N2 influenza strains, N144K, K158N, and N189K occur in the strains except the strain 09-0056. HA1 domain of H3N2 influenza strains in 2009 has lost a glycosylation site at amino acid position 144 while the glycosylation sites of HA1 domain of H3N2 influenza stains isolated in 2008 remained. This study suggested that H3N2 influenza virus in Zhuhai in 2008 was not evolved a novel variant and H3N2 influenza variant in 2009 was attributed to antigenic drift in HA1 district.
Animals ; Antigens, Viral ; immunology ; Cell Line ; China ; Dogs ; Epitopes ; immunology ; Glycosylation ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; metabolism ; Humans ; Influenza A Virus, H3N2 Subtype ; classification ; genetics ; immunology ; isolation & purification ; Mutation ; Phylogeny ; Sequence Analysis, DNA

We report results of a randomized, double-blinded, active-controlled, phase III study conducted to evaluate the immunogenicity and safety of a new trivalent inactivated split-virus influenza vaccine (GC501) manufactured by the Green Cross Corporation in Korea. A total of 283 healthy children aged 6 months to < 18 yr were randomized to receive either GC501 or control. Of the GC501 recipients, seroconversion occurred in 48.5% for A/H1N1, 67.7% for A/H3N2 and 52% for influenza B. The proportion of subjects who had post-vaccination hemagglutination-inhibition titers of 1:40 or greater was 90.7% for A/H1N1, 86.8% for A/H3N2 and 82.4% for influenza B in the GC501 recipients. No serious adverse events related to vaccination, or withdrawals because of adverse events were reported. The majority of solicited adverse events were mild in intensity. GC501 vaccine has good tolerability and favorable immunogenicity in children aged 6 months to < 18 yr. The addition of one more brand of influenza vaccine may allow for better global accessibility of vaccine for epidemics or future pandemics.
Adolescent ; Antibodies, Viral/*blood ; Child ; Child, Preschool ; Double-Blind Method ; Female ; Humans ; Infant ; Influenza A Virus, H1N1 Subtype/*immunology ; Influenza A Virus, H3N2 Subtype/*immunology ; Influenza B virus/*immunology ; Influenza Vaccines/*adverse effects/*immunology ; Male ; Republic of Korea ; Vaccination ; Vaccines, Inactivated/adverse effects/immunology

OBJECTIVETo explore the cross immunity response between two similar strains of influenza A3 virus vaccine from 2007 to 2008.

METHODSHealthy adults aged 18-60 years old without history of flu vaccination were inoculated Anflu ™( 52 cases) or VAXIGRIP ® (137 cases) influenza split vaccine. A micro-hemagglutination inhibition (HI) assay was used to test the serum specimens collected from the subjects before and after vaccination. The seroconversion rate, geometric mean titer (GMT) and antibody protective rate were used to evaluate the effect.

RESULTSThe seroconversion rates of Anflu ™ and VAXIGRIP ® tested by A/Hiroshima/52/2005 virus antigen were 82.7% (95%CI: 69.2% - 91.8%) and 80.3% (95%CI: 72.4% - 86.5%) respectively and there was no significant difference (χ(2) = 0.141, P > 0.05). The seroconversion rates of Anflu™ and VAXIGRIP ® tested by A/Wisconsin/67/2005 (H3N2)-like virus antigen were 71.2% (95%CI: 56.7% - 82.8%) and 73.7% (95%CI: 65.4% - 80.8%) respectively and there was no significant difference observed (χ(2) = 0.126, P > 0.05). GMT of Anflu™ and VAXIGRIP ® tested by A/Hiroshima/52/2005 virus antigen after vaccination increased 11.5 (95%CI: 7.5 - 17.5) times and 13.0 (95%CI: 10.0 - 16.9) times without significant difference (F = 0.497, P > 0.05). GMT of Anflu ™ and VAXIGRIP ® tested by A/Wisconsin/67/2005 (H3N2)-like virus antigen after vaccination increased 9.5 (95%CI: 6.3 - 14.3) and 10.9 (95%CI: 8.5 - 13.7) times, and there was no significant difference either (F = 0.554, P > 0.05). The antibody protective rate of two vaccines before and after immunity tested by A/Hiroshima/52/2005 virus antigen were 48.1% and 54.7% before vaccination and 98.1% and 95.6%after vaccination respectively without significant difference (χ(2) = 0.135 - 0.673, P > 0.05). The antibody protective rates of two vaccines tested by A/Wisconsin/67/2005 (H3N2)-like virus antigen were 11.5% and 13.9%before vaccination and 80.8% and 86.1%after vaccination respectively, and there was no significant difference (χ(2) = 0.178 - 0.834, P > 0.05). But the results tested by A/Hiroshima/52/2005 virus antigen were higher than those of A/Wisconsin/67/2005 (H3N2)-like virus antigen (χ(2) = 7.111 - 52.155, P < 0.01).

CONCLUSIONThe two similar seasonal influenza vaccine strains recommended by WHO had a good cross immunity response, but the systematic error of test existed in two similar stains and the same strains should be used.

Adolescent ; Adult ; Antibodies, Viral ; blood ; immunology ; Cross Reactions ; immunology ; Female ; Hemagglutination Inhibition Tests ; Humans ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza Vaccines ; classification ; immunology ; Influenza, Human ; prevention & control ; Male ; Middle Aged ; Young Adult