Animals ; Humans ; Influenza A virus ; genetics ; immunology ; Influenza Vaccines ; administration & dosage ; genetics ; immunology ; Influenza, Human ; prevention & control ; virology ; Vaccines, Virus-Like Particle ; administration & dosage ; genetics ; immunology

OBJECTIVETo elevate the immunological effect of subunit influenza vaccine in infants and aged people (over 60) using liposomal adjuvant in the context of its relatively low immunity and to investigate the relation between vaccine antigens and liposomal characteristics.

METHODSSeveral formulations of liposomal subunit influenza vaccine were prepared. Their relevant characteristics were investigated to optimize the preparation method. Antisera obtained from immunizinged mice were used to evaluate the antibody titers of various samples by HI and ELISA.

RESULTSLiposomal trivalent influenza vaccine prepared by film evaporation in combinedation with freeze-drying significantly increased its immunological effect in SPF Balb/c mice. Liposomal vaccine stimulated the antibody titer of H3N2, H1N1, and B much stronger than conventional influenza vaccine. As a result, liposomal vaccine (mean size: 4.5-5.5 microm, entrapment efficiency: 30%-40%) significantly increased the immunological effect of subunit influenza vaccine.

CONCLUSIONThe immune effect of liposomal vaccine depends on different antigens, and enhanced immunity is not positively correlated with the mean size of liposome or its entrapped efficiency.

Animals ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; administration & dosage ; immunology ; Liposomes ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; prevention & control ; Specific Pathogen-Free Organisms ; Vaccines, Subunit ; administration & dosage ; immunology

Influenza vaccines are the primary method for controlling influenza and its complications. This study was conducted as a phase 3, randomized, double-blind, controlled, multi-center trial at seven university hospitals to evaluate the immunogenicity and safety of an inactivated, split, trivalent influenza vaccine (GC501, Green Cross Corporation, Yongin, Korea), which was newly manufactured in Korea in 2008. Between September 21 and 26, a total of 329 healthy subjects were recruited for the immunogenicity analysis, while 976 subjects were enrolled for the safety analysis. The GC501 vaccine met both FDA and EMEA criteria with > or = 80% of subjects achieving post-vaccination titers > or = 40 for all three subtypes, even in the elderly. The vaccine was well tolerated with only mild systemic and local adverse events. In summary, GC501 showed excellent immunogenicity and a good safety profile in both young adults and the elderly. The licensure of GC501 might be an important basis in preparation for the future influenza pandemic.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Double-Blind Method ; Humans ; Influenza Vaccines/administration & dosage/*adverse effects/*immunology ; Influenza, Human/*prevention & control ; Male ; Middle Aged ; Republic of Korea ; Vaccination ; Vaccines, Inactivated/administration & dosage/adverse effects/immunology ; Young Adult

OBJECTIVETo understand the epidemiologic characters of influenza in China from 2001 to 2003.

METHODSData of outpatient visits for influenza-like illness (ILI) each week and outbreaks of influenza were collected through National Influenza Surveillance Network, which includes 11 northern and 12 southern provinces of China. Samples were collected in the outpatients of ILI from 2001 to 2003 and influenza viruses were isolated and identified.

RESULTSEpidemiological and laboratory surveillance data showed that the annual seasonality of influenza epidemic was clear. The peak of epidemic of influenza in northern areas was in winter season, during December to January. However, there were three peaks distributed to Spring (Apr.-May.), Summer (Jun.-Aug.) and Winter (Dec.-Jan.) seasons in the southern areas. In the peak months, the number of ILI visits per day and per surveillance hospital had increased two-fold in northern and by 37% in southern China. The baseline of percentages for ILI visits, which calculated with 75th percentiles (P75), was 13.68% in the north and 13.08% in southern China. The age distribution of ILI was related to seasonal types of influenza. When the predominated strain of the season was influenza B virus, the ratio of the ILI visits younger than 15 year-old, increased obviously. When the predominated stains became influenza A virus, the ratio of patient visits for ILI aged over 25 year-old increased. Of 63 outbreaks of influenza, 92% of them occurred at primary and middle schools and usually occurred in May (32%). The type of strains usually changed around June.

CONCLUSIONThe quality of national influenza surveillance system is reliable since it was matched between percentages of ILI visits and rates of influenza virus isolation. The different epidemiologic characteristics in north and south of China was noticed. Peak in spring was shown in southern area and which called for more analysis. The change of the types of strains in the outbreaks during April to June in the southern China could provide data for better understanding on the trend of epidemics in the next season.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Influenza A virus ; Influenza B virus ; Influenza Vaccines ; administration & dosage ; Influenza, Human ; epidemiology ; prevention & control ; virology ; Male ; Middle Aged ; Population Surveillance ; Seasons ; Vaccination

INTRODUCTIONAs preparation against a possible avian flu pandemic, international and local health authorities have recommended seasonal influenza vaccination for all healthcare workers at geographical risk. This strategy not only reduces "background noise", but also chance of genetic shifts in avian influenza viruses when co-infection occurs. We evaluate the response of healthcare workers, stratified by professional groups, to a non-compulsory annual vaccination call, and make international comparisons with countries not at geographical risk.

MATERIALS AND METHODSA cross-sectional study was performed over the window period for vaccination for the 2004 to 2005 influenza season (northern hemisphere winter). The study population included all adult healthcare workers (aged < or =21 years) employed by a large acute care tertiary hospital.

RESULTSThe uptake rates among frontline caregivers--doctors >50%, nurses >65% and ancillary staff >70%--markedly exceeded many of our international counterparts results.

CONCLUSIONGiven its close proximity in time and space to the avian flu pandemic threat, Singapore healthcare workers responded seriously and positively to calls for preventive measures. Other factors, such as the removal of financial, physical and mental barriers, may have played important facilitative roles as well.

Adult ; Animals ; Attitude of Health Personnel ; Birds ; Cross-Sectional Studies ; Disaster Planning ; organization & administration ; Female ; Humans ; Influenza A Virus, H5N1 Subtype ; Influenza Vaccines ; therapeutic use ; Influenza in Birds ; Influenza, Human ; prevention & control ; Male ; Personnel, Hospital ; psychology ; statistics & numerical data ; Seasons ; Singapore ; Vaccination ; utilization

Annual epidemics of seasonal influenza occur during autumn and winter in temperate regions and have imposed substantial public health and economic burdens. At the global level, these epidemics cause about 3-5 million severe cases of illness and about 0.25-0.5 million deaths each year. Although annual vaccination is the most effective way to prevent the disease and its severe outcomes, influenza vaccination coverage rates have been at suboptimal levels in many countries. For instance, the coverage rates among the elderly in 20 developed nations in 2008 ranged from 21% to 78% (median 65%). In the U.S., influenza vaccination levels among elderly population appeared to reach a "plateau" of about 70% after the late 1990s, and levels among child populations have remained at less than 50%. In addition, disparities in the coverage rates across subpopulations within a country present another important public health issue. New approaches are needed for countries striving both to improve their overall coverage rates and to eliminate disparities. This review article aims to describe a broad conceptual framework of vaccination, and to illustrate four potential determinants of influenza vaccination based on empirical analyses of U.S. nationally representative populations. These determinants include the ongoing influenza epidemic level, mass media reporting on influenza-related topics, reimbursement rate for providers to administer influenza vaccination, and vaccine supply. It additionally proposes specific policy implications, derived from these empirical analyses, to improve the influenza vaccination coverage rate and associated disparities in the U.S., which could be generalizable to other countries.
Health Status Disparities ; Humans ; Influenza Vaccines/*administration & dosage ; Influenza, Human/epidemiology/*prevention & control ; Patient Acceptance of Health Care ; United States/epidemiology ; Vaccination/*trends/utilization

Influenza virus is one of the major sources of respiratory tract infection. Due to antigenic drift in surface glycoproteins the virus causes annual epidemics with severe morbidity and mortality. Although hemagglutinin (HA) is one of the highly variable surface glycoproteins of the influenza virus, it remains the most attractive target for vaccine development against seasonal influenza infection because antibodies generated against HA provide virus neutralization and subsequent protection against the virus infection. Combination of recombinant adenovirus (rAd) vector-based vaccine and mucosal administration is a promising regimen for safe and effective vaccination against influenza. In this study, we constructed rAd encoding the globular head region of HA from A/Puerto Rico/8/34 virus as vaccine candidate. The rAd vaccine was engineered to express high level of the protein in secreted form. Intranasal or sublingual immunization of mice with the rAd-based vaccine candidates induced significant levels of sustained HA-specific mucosal IgA and IgG. When challenged with lethal dose of homologous virus, the vaccinated mice were completely protected from the infection. The results demonstrate that intranasal or sublingual vaccination with HA-encoding rAd elicits protective immunity against infection with homologous influenza virus. This finding underlines the potential of our recombinant adenovirus-based influenza vaccine candidate for both efficacy and rapid production.
Adenoviridae* ; Administration, Mucosal ; Animals ; Antibodies ; Head* ; Hemagglutinins* ; Immunization* ; Immunoglobulin A ; Immunoglobulin G ; Influenza Vaccines ; Influenza, Human* ; Membrane Glycoproteins ; Mice* ; Mortality ; Orthomyxoviridae* ; Respiratory Tract Infections ; Seasons ; Vaccination ; Viruses

OBJECTIVETo analyze the status of acute upper respiratory infection and influenza-like illness (ILI) among community residents in Jinan in 2015, and to make a understand of the patient's medical treatment behavior and influenza vaccination coverage status in 2014.

METHODSBalloting method and convenient sampling method were used to launch a household survey. The residents who had been in Jinan for more than 3 months were selected, to investigate the residents' attack ratio of acute upper respiratory and influenza-like from Jan. 8 to Feb. 7, 2015. Totally, 1 300 persons from 410 families were involved in this survey which recovered 1 241 valid questionnaires with the efficiency of 95.5%. Based on the national age-urban demographic statistics in 2010, the attack rates of acute respiratory infections, influenza-like illness were estimated by the direct standardization method, and the influenza vaccination rates were also calculated in this study. χ(2)-test method was used to compare the different status of incidence and vaccination among residents with different features.

RESULTSThe attack rate of acute upper respiratory infection and influenza-like illness in Jinan from January 8, 2015 to February 7, 2015 were 30.2% (375 cases), and 6.1% (76 cases), respectively, with a standardized rate of 29.1% and 5.4%. 5.3% (66 cases) of the residents have vaccinated with the influenza vaccine inoculation, with an adjusted rate of 3.8%. The attack rate difference of acute upper respiratory tract infections was statistically significant between each age group (χ(2)=17.121, P= 0.002). The 0-4 age group had a highest attack rate (45.4%) of acute respiratory infection, while the 15-24 age group got the lowest (26.5%). 38.9% (146 cases) of patients went for a treatment in hospital. Among them, 37.7% (55 cases) of them selected the county level hospitals for treatment, 37.7% (55 cases) selected the community level hospitals, and 24.6% (36 cases) selected the individual clinic. Significant differences of influenza-like illness attack rate between each age group were also found in this study (χ(2)=76.79, P<0.001). 0-4 age group had the highest attack rate (22.7%). 81.6% (62 cases) of the ILI sought treatment in the hospital, of which 53.2% (33 cases) selected county level hospital or above, and 33.9% (21 cases) selected community hospital, and 12.9% (8 cases) selected the individual clinic.

CONCLUSIONThe attack rate of acute upper respiratory infections among the residents of Jinan was high, whereas that of influenza-like illness was relatively low. 0-4 age group had a higher risk of ILI than other age groups. Most of the cases were likely to take the treatment in large hospitals. In general, the coverage rate of influenza vaccination was relatively low.

Ambulatory Care Facilities ; China ; Hospitals ; Humans ; Influenza Vaccines ; administration & dosage ; Influenza, Human ; epidemiology ; Respiratory Tract Infections ; epidemiology ; Surveys and Questionnaires ; Vaccination ; statistics & numerical data

Objective: To investigate the influenza vaccination and its influencing factors among the clinical staff in Xining, Qinghai province, in the 2016-2017 influenza season, and to explore the promoting strategies to encourage the target population for influenza vaccination. Methods: Four sample hospitals were randomly selected from the total 11 tertiary hospitals in Xining city. Clinical staff that worked in the four hospitals and agreed to participate were recruited for investigation via a self-administered questionnaire. Results: During the 2016-2017 influenza season, the coverage rate of influenza vaccines among the clinical staff was 5.14% (95%CI: 4.80%-5.49%). Multivariate logistic regression showed that knowing the priority of vaccination, the frequency of vaccination, effect of vaccination, and possessing higher professional qualifications were major influencing factors for influenza vaccination. The intention on recommendation of seasonal influenza vaccine was higher in vaccinated group than that in the unvaccinated group (χ(2)=99.57, P<0.001). Conclusion: The lower coverage rate was primarily associated with the lack of knowledge about influenza vaccine among the clinical staff of the hospital. Tailored information should be provided to the clinical staff through effective methods to improve vaccination and the recommendation of influenza vaccine.
Attitude of Health Personnel ; China ; Cities ; Health Knowledge, Attitudes, Practice ; Hospitals ; Humans ; Influenza Vaccines/administration & dosage* ; Influenza, Human/prevention & control* ; Logistic Models ; Seasons ; Surveys and Questionnaires ; Vaccination

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications. Currently, China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. In most parts of China, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients need to pay for it. To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC), Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" , based on most recent existing scientific evidences. The main updates include: epidemiology and disease burden of influenza, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, and, IIV3 and IIV4 vaccines'major immune responses, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The recommendations include: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥1 licensed, recommended, and appropriate products. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to pregnant during the influenza season. Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in previous influenza season, 1 dose is recommended. People ≥ 9 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for CDC members who are working on influenza control and prevention, PoVs members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and members of maternity and child care institutions at all levels.
Adult ; Child ; Child, Preschool ; China ; Female ; Guidelines as Topic ; Humans ; Infant ; Influenza Vaccines/administration & dosage* ; Influenza, Human/prevention & control* ; Pregnancy ; Seasons ; Vaccination