The influenza virus is classified as a single-stranded negative-sense RNA virus in Orthomyxoviridae family, with epidemiological properties distinct from common cold. Previous studies have found that influenza infection can cause cardiac damage through various pathways, and patients with cardiovascular diseases are at relatively higher risk of adverse disease outcomes. Influenza vaccination has been proven to provide protective effect on patients with cardiovascular diseases. Currently, there is insufficient emphasis placed by cardiologists and cardiovascular disease patients on the prevention of influenza infection, leading to a low influenza vaccination rate in China. Therefore, based on the current clinical research progress and relevant guidelines, combined with the safety, feasibility and health economic benefits of influenza vaccinating in patients with cardiovascular diseases, as well as clinical experience from experts, this article proposes expert opinions on influenza vaccination in common cardiovascular diseases aiming to raise awareness of influenza prevention and benefiting patients.
Humans ; Cardiovascular Diseases/prevention & control* ; Influenza Vaccines/administration & dosage* ; Influenza, Human/prevention & control* ; Vaccination ; Expert Testimony

OBJECTIVE: Despite the global decrease in influenza infections during the coronavirus disease 2019 (COVID-19) pandemic, seasonal influenza remains a significant health issue. South Korea, known for its robust pandemic response and high influenza vaccination rates, offers a unique context for examining changes in vaccination trends during the pandemic. Using nationally representative data, we aimed to understand the impact of the pandemic on influenza vaccination behavior over a 12-year period and to identify vulnerable groups. METHODS: We analyzed influenza vaccination rates in South Korea between 2011-2022, focusing on pandemic-related impacts. The data of 2,426,139 adults (≥ 19 years) from the Korea Community Health Survey were used to assess demographic and sociological factors influencing vaccination behaviors. RESULTS: We observed an increase in influenza vaccination rates during the pre-COVID-19 period from 2011-2013 (weighted prevalence: 46.68% [95% confidence interval ( CI): 46.55-46.82]) to 2017-2019 (weighted prevalence: 52.50% [95% CI: 52.38-52.63]). However, a significant decline was observed in 2022, the late-COVID-19 pandemic period (weighted prevalence: 55.78% [95% CI: 55.56-56.01]), compared with the mid-pandemic period in 2021 (weighted prevalence: 59.12% [95% CI: 58.91-59.32]), particularly among populations traditionally prioritized for influenza vaccination, including older adults (≥ 65 years) and patients with chronic diseases and low educational and income levels. CONCLUSION The influenza vaccination rate in South Korea was significantly affected by the COVID-19 pandemic, showing a notable decrease among vulnerable demographic groups. This suggests the need for targeted public health strategies to address vaccine hesitancy and improve vaccination rates, particularly among high-risk populations.
Humans ; Republic of Korea/epidemiology* ; COVID-19/epidemiology* ; Adult ; Middle Aged ; Influenza Vaccines/administration & dosage* ; Male ; Female ; Influenza, Human/epidemiology* ; Aged ; Vaccination/statistics & numerical data* ; Young Adult ; Pandemics ; SARS-CoV-2

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

Influenza virus infection is a respiratory infectious disease that can seriously affect human health. Influenza viruses can have antigenic variation and changes frequently, which results in rapid and widespread transmission resulting in annual epidemics and outbreaks in population gathering places such as schools, kindergartens and nursing homes. WHO estimated that seasonal influenza epidemics could cause 3 to 5 million severe cases annually, and 290 000 to 650 000 deaths globally. Pregnant women, young children, the elderly, and persons with chronic illnesses are at high risk for severe illness and death associated with influenza virus infection. Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) which includes split-virus influenza vaccine and subunit vaccine, and quadrivalent inactivated influenza vaccine (IIV4) which is split. Except a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients should pay for it. In 2018, China CDC issued the "Technical Guidelines for Seasonal Influenza Vaccination in China (2018-2019)" (Guide 2018). In the past year, new research evidences have been published both in China and abroad, and new seasonal influenza vaccine has been licensed in China. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the Influenza Vaccination Technical Working Group (TWG) of National Immunization Advisory Committee (NIAC) updated the Guide 2018 and compiled the "Technical Guidelines for Seasonal Influenza Vaccination in China (2019-2020)" . Major updates include the following: First, new research evidences especially studies of China, including disease burden, effectiveness, vaccine-avoidable disease burden, vaccine safety monitoring, and cost-effectiveness and cost-benefit. Second, policies and measures for influenza prevention and control issued by National Health Commission (PRC) in the past year. Thirdly, new type seasonal influenza vaccine licensed and issued in 2019-2020 in China. Fourth, northern hemisphere influenza vaccination composition for the 2019-2020 season was updated for both IIV3 and IIV4. 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 one influenza vaccine product over another for persons whom can accept more than one 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 to 59 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 become pregnant during the influenza season. Children aged 6 months through 8 years 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 2018-2019 influenza season or prior, 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 available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the CDCs at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels. These guidelines will be updated periodically as new evidence becomes available.
Adult ; Aged ; Child ; Child, Preschool ; China ; Cities ; Female ; Humans ; Infant ; Influenza Vaccines/administration & dosage* ; Influenza, Human/prevention & control* ; Practice Guidelines as Topic ; Pregnancy ; Seasons ; Vaccination

In China, the control and prevention programs on any disease has always been based on comprehensive strategies. Take influenza as an example, related contents would include: strengthening the surveillance, recommendation and promotion of vaccination, rational use of antiviral drugs, conducting outbreak investigation and control, and publicizing individual protective measures, etc. In terms of the response to challenges, specific proposals would include: adjustment of case reports, optimization of surveillance systems, reinforcement of vaccination recommendation by health care workers, improvement of access to vaccination, development of rapid diagnostic reagents, and rational use of antiviral drugs, etc.
Antiviral Agents/therapeutic use* ; China/epidemiology* ; Disease Outbreaks/prevention & control* ; Health Personnel ; Humans ; Influenza Vaccines/administration & dosage* ; Influenza, Human/prevention & control* ; Primary Prevention/organization & administration* ; Program Development ; Seasons ; Vaccination

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

Objective: To understand the epidemiological characteristics of influenza in Guangdong province, during the winter of 2017-2018, to provide evidence for response to the diversity of influenza, in different seasonal patterns. Methods: Data on weekly influenza surveillance from January 2016 to April 2018, were collected in Guangdong. Information on patients with Influenza-like illness (ILI), on influenza virus positive rates and on outbreaks during the winter of 2017 to 2018, was analyzed and compared with those in spring of 2016 and summer of 2017. χ(2) test and Fisher exact test were used. Results: In the above said winter, the average percentage of visits for ILI in 28 hospitals where sentinel surveillance program had been set, was 4.99% (157 235/3 149 656), which was above the level of the same period in the previous five years. The positive rates of influenza virus among samples collected from ILI outpatients and hospitalized cases under severe acute respiratory infection (SARI) were 28.33% (2 137/7 543) and 14.93% (256/1 715), with the proportions of B (Yamagata) as 70.43% (1 505/2 137) and 73.05% (187/256) respectively. A total of 257 influenza outbreaks were reported in the winter period, with 82.49% (212/257) occurred in elementary schools. Cases aged 6-14 years occurred in winter and spring appeared of having higher positive rate than those seen in summer (P<0.05) whereas elderly cases aged 60 and above showed higher positive rate in summer than those in winter and spring two seasons (P<0.05). Conclusions: Epidemiological characteristics of influenza appeared in Guangdong province, during the winter from 2017 to 2018, were correlated to Influenza B (Yamagata). Capacity on the implementation of surveillance programs and on the coverage of vaccination should be improved and increased in order to control influenza in different epidemic seasons, in Guangzhou.
Adolescent ; Adult ; Aged ; Child ; China/epidemiology* ; Disease Outbreaks ; Epidemics ; Humans ; Infant ; Influenza Vaccines/administration & dosage* ; Influenza, Human/virology* ; Middle Aged ; Orthomyxoviridae/isolation & purification* ; Population Surveillance ; Respiratory Tract Infections/epidemiology* ; Seasons ; Sentinel Surveillance ; 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

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

OBJECTIVETo investigate the differences in free influenza vaccination rate among different family structures of the elderly population in Beijing under the free vaccination policy.

METHODSA cross sectional study was conducted by a multi-stage cluster sampling from July to August in 2013. A total of 1 717 individuals were selected to answer a self-designed questionnaire of demographic characteristics and basic information about receiving free influenza vaccination and 1 637 of which were valid. The chi-square test for dichotomous variables was calculated to examine the relationship between vaccine status and family characteristics. Predictor variables were selected as variables for non-conditional logistic regression model to determine potential independent predictors of vaccine uptake.

RESULTSThe free influenza vaccination rate in elderly population was 38.8% (634/1 637) in 2013. The rate in the old people who lived alone was the highest which was 47.5% (58/122). The rate in the old people who lived with children and spouse was 34.6% (175/506). There was a significant difference in coverage rate among different family structures (χ(2)=11.57, P=0.009). The rate in the old people who lived with spouse only, lived with children only and other types were 41.5% (322/778) , 34.7% (69/201), and 33.3% (10/30), respectively. In a multi-factor model, there was a significant difference in vaccination rate among different family structures after other confounding factors were controlled. The odds ratios (95% CI) of the people living with spouse only, people living with children only and people living with spouse and children were 0.90 (0.60-1.33) , 0.59 (0.37-0.96) , and 0.63 (0.42-0.96), respectively.

CONCLUSIONThe vaccination rate in the old people living alone was low. The health education should be conducted not only in the elderly people but also in their family members.

Aged ; Beijing ; Child ; Cross-Sectional Studies ; Family Characteristics ; Health Education ; Humans ; Influenza Vaccines ; administration & dosage ; Logistic Models ; Spouses ; Surveys and Questionnaires ; Vaccination ; statistics & numerical data