EV71 infection has become a serious public health threat especially among young children. Yet, at present, no specific antiviral drug against EV71 infection is available. A number of scientists are studying various kinds of vaccines, including inactivated vaccine, virus-like particle vaccine, DNA vaccine, synthetic peptide vaccines, and transgenic oral vaccine. This article reviews the recent advancement in the design of various kinds of vaccine against EV71 as well as their prospective usefulness, effectiveness, weakness and developments in the foreground.
Enterovirus A, Human ; immunology ; Hand, Foot and Mouth Disease ; immunology ; prevention & control ; Humans ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Vaccines, Inactivated ; immunology ; Vaccines, Synthetic ; immunology ; Viral Vaccines ; immunology

Numerous studies have indicated that human metapneumovirus (hMPV) is an important viral pathogen in acute respiratory infections in children, presenting similar manifestations with respiratory syncytial virus (RSV). HMPV infection peaks in the winter-spring season and is more prevalent in younger ages, especially in children less than 1 year old. Host innate immune response has been implicated in recognition of pathogen-associated molecular patterns (PAMPs) of the virus. This recognition occurs through host pattern recognition receptors (PRRs). Toll like receptors (TLRs) are one of the largest class of PRRs which initiate and regulate adaptive immune responses. Some studies have indicated that TLR 3 and TLR 4 may play critical roles in hMPV infection. Construction of recombinant mutant viruses lacking one or two N-linked glycosylation sites in the F protein by using site-directed mutagenesis and reverse genetics may be helpful for developing attenuated live vaccines.
Humans ; Metapneumovirus ; immunology ; Paramyxoviridae Infections ; etiology ; prevention & control ; Vaccines, Attenuated ; immunology ; Vaccines, Synthetic ; immunology ; Viral Vaccines ; immunology

OBJECTIVETo evaluate the immunogenicity, safety, and dosage of a new inactivated hepatitis A vaccine administered to young adults.

METHODSOne hundred and four normal adult volunteers, seronegative for hepatitis A virus and hepatitis B surface antigen, were randomly assigned to one of three groups. The high-dose group received a primary dose of 1000 units of the new vaccine, the low-dose group received a primary dose of 500 units of the same vaccine, and the Havrix group received a primary dose of 1440 enzyme-linked immunosorbent assay units of Havrix, a licensed inactivated hepatitis A vaccine. All groups received a booster dose of the same vaccine 6 months after the primary dose. Local and systemic adverse reactions, seroconversion rates, and geometric mean titers of hepatitis A virus antibodies were measured in all three groups.

RESULTSLocal and systemic reaction types and rates were similar in all three groups after primary and booster doses, although local reactions were more frequent in the Havrix group following the primary dose. No serious adverse reactions occurred. One month after the primary dose, the seroconversion rate was 87.5% in the high-dose group, 70.0% in the low-dose group, and 50.0% in the Havrix group (P = 0.001, versus the high-dose group). At month 6 (before administration of the booster dose), seroconversion rates were 96.9% in the high-dose group, 65.0% in the low-dose group (P = 0.0029), and 68.8% in the Havrix group (P = 0.007). All subjects in all groups seroconverted by one month after receipt of the booster dose. Geometric mean titers were similar in all three groups at month 1, but were higher in the high-dose group (264 mIU/ml) than those in the Havrix group (135 mIU/ml) at month 6 (P = 0.0013). One month after the booster dose, geometric mean titers in the high-dose group (2747 mIU/ml) were higher than those in the low-dose group (1657 mIU/ml) (P = 0.0223) or in the Havrix group (1316 mIU/ml) (P = 0.01).

CONCLUSIONSThis new inactivated hepatitis A vaccine is immunogenic and safe; two doses of either 500 or 1000 units can induce hepatitis A virus antibodies well above the protection level.

Adolescent ; Adult ; Hepatitis A Vaccines ; adverse effects ; immunology ; Humans ; Vaccines, Attenuated ; adverse effects ; immunology

Adenoviridae ; genetics ; Animals ; Dengue Vaccines ; immunology ; Humans ; Plasmids ; Recombinant Fusion Proteins ; immunology ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Vaccines, Synthetic ; immunology

Influenza, caused by influenza virus, is a serious respiratory illness which poses a global public health threat. Vaccination is the primary strategy for the prevention and control of influenza. Although both inactivated vaccines and the live attenuated vaccines are effective in preventing influenza, the current vaccines have poor efficacy in the elderly and fail to provide protection against heterosubtype viruses. Development of a safer and more effective influenza vaccine that provides broad cross protection, overcoming the intrinsic limitation of the current vaccines, has been a scientific challenge. During the past decades, structural biology, reverse genetic and other virological technologies developed quickly and sped the progress of influenza vaccinology. Some new strategies for developing influenza vaccine have been generated, produced encouraging results, which showed great prospect as next-generation of influenza vaccines.
Disease Outbreaks ; prevention & control ; Hemagglutinin Glycoproteins, Influenza Virus ; immunology ; Humans ; Influenza Vaccines ; biosynthesis ; immunology ; Influenza, Human ; immunology ; prevention & control ; virology ; Orthomyxoviridae ; immunology ; Vaccines, Attenuated ; immunology ; Vaccines, Inactivated ; immunology

Classical swine fever (CSF), an acute and highly contagious disease of swine, is caused by classical swine fever virus. CSF is one of the most devastating diseases to the pig industry worldwide and results in serious economic losses. Currently prophylactic vaccination is still an important strategy for the control of CSF. Live attenuated vaccines (such as C-strain) are safe and effective. However, there are significant changes in the clinical features of CSF, displaying concurrent typical and atypical CSF, and simultaneous inapparent and persistent infections. Immunization failure has been reported frequently and it is difficult to distinguish between wild-type infected and vaccinated animals (DIVA). So there is an urgent need to develop more effective and safer DIVA or marker vaccines for the control of CSF. In this review, some of the most recent advances in new-type vaccines against CSF, including DNA vaccines, live virus-vectored vaccines, protein or peptide-based vaccines, gene-deleted vaccines and chimeric pestivirus-based vaccines, are reviewed and discussed.
Animals ; Classical Swine Fever ; prevention & control ; Classical swine fever virus ; Swine ; Vaccination ; veterinary ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Vaccines, Subunit ; immunology ; Viral Vaccines ; immunology

Biomedical Research ; China ; Freeze Drying ; Hepatitis A Vaccines ; adverse effects ; immunology ; Humans ; Safety ; Vaccines, Attenuated ; adverse effects ; immunology

OBJECTIVEUsing the advantages of Japanese encephalitis live attenuated and inactivated vaccine, to reduce the rate of immunization reaction and to increase the effect, we conducted a study on the strategy of immunization in Japanese encephalitis using live attenuated vaccine combined with inactivated vaccine.

METHODSObserving the safety and immune effects of different groups.

RESULTSData on side effect showed that the rate of moderate and severe systematic reactions of the group who were inoculated with combined vaccine was 0.73%, with local reaction 1.46% while the combined rate of moderate and severe systematic reaction of the group who were inoculated with inactivated vaccine was 2.8%. Under the detection of serum neutralizing antibody, the GMT rose from 1:1.05 - 1:3.35 before vaccination to 1:47.34 - 1:101.30 after vaccination in the different groups. Neutralizing antibody was detected in 97.67% of the combined group. There was a significant difference by comparing neutralizing antibody seroconversion rate of the combined group with the inactivated group (chi(2) = 3.89, P < 0.05), but no significant difference with attenuated group (chi(2) = 0.74, P > 0.05).

CONCLUSIONResults showed that in children who previously had been immunized with two doses of inactivated vaccine, the booster administration of live attenuated vaccine was both effective and safe.

Antibodies, Viral ; blood ; Child, Preschool ; Encephalitis Virus, Japanese ; immunology ; Humans ; Immunization ; Japanese Encephalitis Vaccines ; administration & dosage ; adverse effects ; immunology ; Vaccines, Attenuated ; immunology ; Vaccines, Inactivated ; immunology

The fusion protein (F) gene of Newcastle disease virus was amplified by polymerase chain reaction (PCR) from the recombinant plasmid pVAX1-F, and subcloned into eukaryotic expression vector pmcDNA3. 1+. The F gene was identified by sequencing. The recombinant plasmid was transformed into attenuated Salmonella typhimurium SL7207, and the recombinant was designated as SL7207 (pmcDNA3. 1-F). In vitro and in vivo experiments showed that the plasmid stability of pmcDNA3. 1-F was apparently higher than that of pcDNA3. 1-F in SL7207. In order to compare the immune response induced by these two re combinant bacteria, BALB/c mice were immunized orally with them at the dosage of 2 x 10(9) CFU respectively. Both SL7207(pcDNA3. 1-F) and SL7207(pmcDNA3. 1-F) initiated F-specific serum and mucosal antibodies in immunized mice. Furthermore, 4-day-old SPF chickens were immunized with SL7207(pcDNA3. 1-F) and SL7207(pmcDNA3. 1-F) at the dosage of 5 x 10(9) CFU and boosted two weeks later with the same dosage. Humoral and intestinal mucosal immune responses were observed and their levels were significantly higher than that of negative and positive controls. The result of protective efficacy showed that the chickens immunized with SL7207(pmcDNA3. 1-F) had the protective rate of 70.0%, higher than that of the SL7207 (pcDNA3. 1-F) with 50.0%. In summary, the DNA vaccine delivered by attenuated Salmonella typhimurium has good immunogenicity. A novel mucosal DNA vaccine has been developed and could be useful for controlling the infection and epidemic of Newcastle disease in the poultry.
Animals ; Chickens ; Female ; Immunization ; Mice ; Mice, Inbred BALB C ; Newcastle disease virus ; immunology ; Plasmids ; Salmonella typhimurium ; genetics ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Viral Vaccines ; immunology

Listeria monocytogenes (LM), a Gram-positive facultative intracellular bacterium, can be used as an effective exogenous antigen expression vector in tumor-target therapy. But for successful clinical application, it is necessary to construct attenuated LM stain that is safe yet retains the potency of LM based on the full virulent pathogen. In this study, attenuated LM and recombinants of LM expressing melanoma inhibitory activity (MIA) were constructed successfully. The median lethal dose (LD(50)) and invasion efficiency of attenuated LM strains were detected. The recombinants were utilized for immunotherapy of animal model of B16F10 melanoma. The level of MIA mRNA expression in tumor tissue was detected by using real-time polymerase chain reaction (PCR) with specific sequence, meanwhile the anti-tumor immune response was assayed by flow cytometric analysis and enzyme-linked immunosorbent spot (ELISPOT) assay. The results showed the toxicity and invasiveness of attenuated LM were decreased as compared with LM, and attenuated LM expressing MIA, especially the double-genes attenuated LM recombinant, could significantly induce anti-tumor immune response and inhibit tumor growth. This study implicates attenuated LM may be a safer and more effective vector for immunotherapy of melanoma.
Animals ; Cancer Vaccines ; genetics ; immunology ; Extracellular Matrix Proteins ; genetics ; immunology ; Listeria monocytogenes ; immunology ; Male ; Melanoma ; genetics ; immunology ; Mice ; Mice, Inbred C57BL ; Vaccines, Attenuated ; genetics ; immunology