Analysis on the intention and influencing factors of free influenza vaccination among the elderly people aged 70 and above in Hangzhou in 2022

BackgroundAlthough influenza vaccination is recommended for people aged 70 and above in Hangzhou, and the vaccine is provided free of charge, the elderly influenza vaccination rate is still low. The purpose of this study was to understand the barriers and motivations of older people in deciding to receive free influenza vaccine through questionnaires.MethodsThe method of stratified random sampling was adopted to take samples. A questionnaire survey was conducted among the elderly aged 70 years and above by face-to-face interview or telephone interview.ResultsA total of 11,663 elderly people aged 70–100 years were successfully and effectively interviewed. 85.98% of the respondent were willing to get the influenza shot, 8.91% were unwilling to get the influenza shot, and 5.11% were on vaccine hesitancy. The people of age of 70–79 years old (hesitancy: OR70~79 = 0.668, 95%CI: 0.571 0.782, Unwilling: OR70 − 79 = 0.755, 95%CI: 0.622 0.916), primary school degree or below (hesitancy: ORSecondary school degree or above = 1.467, 95%CI: 1.249 1.724, Unwilling: ORSecondary school degree or above = 1.255, 95%CI: 1.028 1.535), remote areas (hesitancy: ORnear central urban area = 2.111, 95%CI: 1.604 2.778, ORcentral urban area = 2.957, 95%CI: 2.255 3.877, Unwilling: ORnear central urban area = 1.687, 95%CI: 1.230 2.313. ORcentralurbanarea = 2.218, 95%CI: 1.626 3.027), and convenient for movement (hesitancy: ORyes = 0.494, 95%CI: 0.420 0.580, Unwilling: ORyes = 0.585, 95%CI: 0.480 0.713), understanding of the free vaccine policy (hesitancy: ORunderstand = 0.204, 95%CI: 0.171 0.245, Unwilling: ORunderstand = 0.164, 95%CI: 0.128 0.210), influenza knowledge level≥ 13 points (hesitancy: OR≥13points = 0.628, 95%CI: 0.533 0.739, Unwilling: OR≥13points = 0.538, 95%CI: 0.437 0.662), influenza vaccine knowledge level≥ 12 points (hesitancy: OR≥12points = 0.422, 95%CI: 0.350 0.508, Unwilling: OR≥12points = 0.370, 95%CI: 0.290 0.472), and social trust level ≥ 12 points (hesitancy: OR≥12points = 0.134, 95%CI: 0.112 0.160, Unwilling: OR≥12points = 0.220, 95%CI: 0.180 0.269) are more willing to receive free influenza vaccine.ConclusionThe proportion of elderly people aged 70 and above who are willing to receive free influenza vaccine is high in Hangzhou. But the level of knowledge about influenza, vaccine and trust in society is low. The government should continue to improve the elderly's awareness and trust in society through medical staff, family members, television and radio media, and guide the elderly to actively vaccinate against influenza. Effective publicity should be carried out through the above channels to guide the elderly to actively vaccinate against influenza

Analysis of Adverse Events Post-13-Valent Pneumococcal Vaccination among Children in Hangzhou, China

With the widespread use of the 13-valent pneumonia vaccine (PCV13) in China, monitoring adverse events following immunization (AEFIs) is critical. We conducted a descriptive analysis of the AEFI occurrences reported within Hangzhou between the years 2020 and 2023, including the temporal trend of case reports and variables such as sex, age, type of PCV13, dose number, type of reporter, cause-specific classification, severity, and onset from vaccination. Vaccine safety signals were analyzed using reporting odds ratios (RORs). Over the 4 years analyzed in the study, 2564 AEFI cases were reported, including seven severe cases. Most AEFIs occurred within 0–1 days after vaccination (2398, 93.53%), with over half affecting infants aged 1.5–6 months of age. No statistically significant difference was observed between PCV13-TT and PCV-CRM197. Seasonal differences in AEFI reports were noted. Positive signals were detected for fever (ROR-1.96SE: 1.64) and persistent crying (ROR-1.96SE: 1.61). Four serious AEFI cases were coincidental events, while three others were considered vaccine-related cases (including one case each of allergic reaction, febrile seizure, and thrombocytopenia). The safety and tolerability of PCV13 are good, and attention should be paid to severe AEFIs, as well as long-term safety disparities between different types of PCV13

Hepatitis B virus infection seromarkers among college freshmen and their immune responses to different vaccination policies of hepatitis B vaccine

Background College students are one of the susceptible population of Hepatitis B virus (HBV) infection. We aim to delineate HBV infection seromarkers among college freshmen and to evaluate immunological response of vaccination immunization for hepatitis B vaccine (HepB). Methods A simple random sampling method was adopted to select subjects and who met the ”inclusion and exclusion criteria” and who with history of vaccination were selected as the observation objects. HBsAg and anti-HBs levels were detected before revaccination. Subjects with negative anti-HBs before immunization were inoculated with 20 ug HepB according to the 0-1-6 procedure and those with weak positive anti-HBs before immunization were inoculated with 1-dose 20 ug HepB. Anti-HBs levels were detected after HepB booster. Combined with the results of anti-HBs, their immune response to HepB and influencing factors in freshmen were investigated. Anti-HBs before immunization was negative and ≥10 m IU/ml after immunization was considered positive conversion; anti-HBs before immunization was weak positive and anti-HBs≥100 m IU/ml after immunization was also considered positive conversion. Results A total of 10645 freshmen were included. The total rate of HBsAg carriers was 0.6% (63/10645), and the strong positive rate of anti-HBs was 16.1% (1706/10645), the weak positive rate was 14.4% (1526/10645).1286 freshmen were vaccinated with HepB and completed the questionnaire survey. About 79.0% (154/195) of freshmen’s anti-HBs turned strong positive after receiving 1-dose HepB and 100.0% (1091/1091) turned positive after receiving 3-doses HepB. The Geometrical Mean Titer (GMT) of anti-HBs was significantly influenced by gender, registration and the immunization doses of HepB. Conclusion The HBsAg carrying rate and anti-HBs positive rate of college freshmen were low, and the HepB has a good effect on the immunity of college freshmen. Increasing the immunization rate of HepB is very important for the prevention and control of hepatitis B

Booster immunization of meningococcal meningitis vaccine among children in Hangzhou, China, 2014-2019.

BackgroundDespite China's Expanded Program on Immunization (EPI) provides 2 doses of group A and group C meningococcal polysaccharide vaccine (MPV-AC) for children at 3 years and 6 years old, more self-paying group ACYW135 meningococcal polysaccharide vaccines (MPV-ACYW135) have been used as an alternative to MPV-AC to prevent Neisseria meningitidis serogroup C,Y,W135. We provide recommendations for Chinese booster immunization of meningococcal meningitis vaccine by analyzing the service status of MPV-AC and MPV-ACYW135.MethodsReported data of routine immunization coverage from all districts of Hangzhou registered in the China Information Management System For Immunization Programming (CIMSFIP) between 2014 to 2019 were described and evaluated. Descriptive epidemiological methods were used to characterize the data. Adverse event following immunization (AEFI) were collected from Chinese national adverse event following immunization information system (CNAEFIIS) to compare the safety of MPV-AC and MPV-ACYW135.Results1376919 doses of booster immunization of meningococcal meningitis vaccine (MenV) in CIMSFIP were conducted in China Hangzhou from 2014 to 2019, with reported immunization coverage rates above 95%. The proportion of children using MPV-ACYW135 increased from 12.63% in 2014 to 29.45% in 2019. The incidence of AEFI of MPV-AC and MPV-ACYW135 were 49.75 per 100,000 and 45.44 per 100,000, respectively, without statistical difference.ConclusionChildren in Hangzhou had high booster immunization of MenV coverage. The use amount and use rate of MPV-ACYW135 increased year by year, indicating more and more parents had chosen MPV-ACYW135 as an alternative to MPV-AC at their own expense for children. The use proportions of MPV-ACYW135 were different in urban, suburban and rural areas. Both MPV-AC and MPV-ACYW135 were safe for children

Seroepidemiology of varicella in Hangzhou, China in the vaccine era

Objective To delineate seroepidemiology of VZV in children aged 1–14 years in Hangzhou, to evaluate immunological response of VarV via 2 dose regimen immunization of VarV, for improving immunization strategy of VarV. Methods From 2014–2016, a multi-stage stratified random sampling method was employed to select participants included via physical examination for children in the Community Health Centre in Hangzhou. Results were compared among 11 various age groups: 1-,2-,3-,4-,5-,6-,7-,8-,9-,10-,11–14 years. Demographic data and vaccination history of all subjects derived from Zhejiang Information System for Immunization Program. Then, the second dose of the VarV was conducted on children aged 4–6 years who had immunization history of one dose of VarV. ELISA was used to detect VZV IgG in serum samples. Results 895 subjects with available information were included. The rate of VZV IgG seropositivity was 65.59% and the geometric mean concentration (GMC) for VZV IgG was 5.14 ± 1.89 mIU/ml. The GMC in urban subjects were higher than rural ones. Both the rate of VZV IgG seropositivity and the GMC in children aged 4–6 years groups were statistically lower than participants younger than 4 years and aged 7–14 years (1-,2-,3-,7-,8-,9-,10-,11–14 years). 627 subjects had immunization history of VarV. Both the rate of VZV IgG seropositivity and the GMC in subjects had immunization history of VarV was higher than who had no immunization history.90 subjects were included after the 2nd dose immunization of VarV. Both the rate of VZV IgG seropositivity and the GMC were significantly increased after the immunization of the 2nd dose of VarV. Conclusions The GMC for VZV IgG in children aged 4–6 years were lower than participants groups (1-,2-,3-,7-,8-,9-,10-,11–14 years).2 doses regimen immunization of VarV are effective for increasing both the rate of VZV IgG seropositivity and the GMC in these subjects

Survey of contraindications in children's routine vaccination in Hangzhou, China

Objective To describe the epidemiological characteristics of contraindications in children routine vaccination, to evaluate vaccination doctors’ ability to determine contraindications. Method Using cross-section study, 34 urban and 15 suburb units were selected from 206 Community Health Center (CHC) in Hangzhou, China. Subjects were all children coming to CHCs for routine vaccination. All situations considered to be unsuitable for vaccination were recorded as contraindications. 3 experts were used to classify these abnormal records as true or false contraindications. Then, the multi-analysis was used to find factors related with the rate of false contraindications. Results There were 2801 children with 2969 contraindications in the present study. The prevalence of contraindications was 3.03‰ by dose of vaccines. Cough (24.78%), fever (21.86%) and medication (19.54%) were the most common contraindications in children routine vaccination. Measles-rubella vaccine (MR) (6.78‰), measles-mumps-rubella vaccine (MMR) (5.87‰) and hepatitis B vaccine (Hep B) (5.25‰) had higher prevalence of contraindications than other vaccines. According to the evaluation of 3 experts, about 13.53% of contraindications were misdiagnosed by vaccination doctor. The rate of misdiagnosed contraindications was correlated with the sex, age and educational background of vaccination doctor, total dose of vaccination of CHC. Conclusion A portion of children might miss the routine vaccination because of misdiagnosed contraindications. More investigations are needed to report the epidemiological distribution of contraindication in routine vaccination of children

Primary immunization of meningococcal meningitis vaccine among children in Hangzhou, China, 2008–2017

Background Although China’s Expanded Program on Immunization (EPI) provides two doses of group A meningococcal polysaccharide vaccine (MPV-A) for children younger than 2 y, more self-paying group A and group C meningococcal polysaccharide conjugate vaccine (MCV-AC) has been used as an alternative to MPV-A, to prevent Neisseria meningitidis serogroup C (Men-C) earlier. We evaluated the pattern of MPV-A and MCV-AC utilization to provide evidence for China to upgrade the national meningococcal meningitis vaccination strategy. Methods Children born between 2008 and 2017 registered in Hangzhou’s Immunization Information System (HZIIS) were included. Descriptive epidemiological methods were used to characterize the data. Adverse event following immunization (AEFI) was collected from Chinese national adverse event following immunization information system (CNAEFIIS) to compare the safety of MPV-A and MCV-AC. Results Data of 1149,027 children from HZIIS were analyzed. The average immunization rate of meningococcal meningitis vaccine (MenV) was 97.50%. Percentages of children using MPV-A-only, MCV-AC-only, and MPV-A/MCV-AC sequential schedules were 68.20%, 29.73%, and 2.07%, respectively. The vaccination rate of MCV-AC-only increased by age and it was higher in resident children than migration children. The incidence rate of AEFI of MPV-A and MCV-AC was 53.36 per 100,000 and 62.13 per 100,000, respectively. Conclusion Children in Hangzhou had high MenV coverage. MCV-AC-only schedule use increased by year and was higher in urban areas among locally born children. Both MPV-A and MCV-AC were safe for children, while MCV-AC could protect against Men-C more effectively. This supports the rationale to introduce MCV-AC into China’s EPI system for free instead of MPV-A

Seroepidemiology of pertussis in Hangzhou, China, during 2009–2017

Objective: To delineate seroepidemiology of pertussis in Hangzhou, to evaluate the protection levels of pertussis among healthy populations, for improving prevention strategy of pertussis.Methods: During 2009–2017, a multistage stratified random sampling method was employed to select participants included via physical examination for subjects in several Community Health Centers in Hangzhou. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect Immunoglobulin G (IgG) antibodies against pertussis in serum samples. Results were compared among 11 age groups. Univariate and multivariate analysis were used to analyze the associations among the rates of pertussis IgG seropositivity and the geometric mean concentration (GMC) levels of pertussis IgG and the related factors.Results: A total of 3360 subjects with available information were included, with 1745 male and 1615 female. Of these, 59.6% subjects had a clear immunization history of diphtheria–tetanus–pertussis vaccine (DTP). The vaccination rates of DTP had a declined trend with older age. The rate of pertussis IgG seropositivity was 69.9% (95% confidence interval: 68.3–71.5) and the GMC for pertussis IgG was 48.46 U/ml. Significantly higher seropositivity and GMC for pertussis IgG were found in subjects that had inoculation vaccine history or unknown history when compared those without inoculation of vaccine, lower in age groups <10, 20–29, and 30–39 y when compared to the other age groups evaluated.Conclusions: There are different distribution profiles both of the seropositivity and GMC for pertussis IgG for different age groups and immunization history of vaccine groups. In order to prevent pertussis occurrence, it is important to employ a booster dose of pertussis vaccine in adolescents and adults

Vaccination pattern of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in Hangzhou, China: a coverage and adverse events following immunization of different age groups

Background: 23-valent pneumococcal polysaccharide vaccine (PPSV23) has been used to prevent pneumococcal disease, and PPSV23 became available in 2003 in Hangzhou, China as a private-sector, vaccinee-chosen vaccine. No national guidelines for PPSV23 have been developed. We analyzed PPSV23 coverage and utilization in Hangzhou to determine patterns of PPSV23 use and the occurrence of adverse events following immunization (AEFI) in Hangzhou. Materials and Methods: Individuals over 2 years of age in Hangzhou were included. Vaccination data during 2006–2017 was retrieved from Hangzhou’s Immunization Information System (HZIIS). We used descriptive epidemiological methods to determine PPSV23 usage patterns and AEFI occurrence. Results: In 2017, there were 9,027,973 persons above 2 years of age with the coverage of PPSV23 of 2.98%. The coverage of PPSV23 among elders ranged from 0.17% to 0.69%, and the overall coverage was higher in urban areas (3.70%) than in rural (3.34%) and suburban areas (2.16%). 93.45% of 268957 recipients were vaccinated with PPSV23 at 2–4 years of age. 394 AEFI of PPSV23 cases were reported to the Chinese national adverse event following immunization information system (CNAEFIS) during 2008–2017, with the reporting rate of 140.39 per 100,000 doses. Conclusion: Persons in Hangzhou had overall low PPSV23 vaccination coverage especially for adults. Most of PPSV23 were used in children, while the proportion of the old population over 60 years slightly increased over year. PPSV23 was safe with a low reported AEFI rate, which was a little higher for children than for the elderly (over 60 years)

Epidemiological characteristic of rubella by age group during 12 years after the national introduction of rubella vaccine in Hangzhou, China

This study aimed to evaluate the implementation and impact of rubella-containing vaccine (RCV) by describing the rubella epidemiology and seroepidemiology in Hangzhou. We collected rubella cases of Hangzhou in the Information System for Disease Control and Prevention in China between 2009 and 2020, and performed a descriptive analysis. We applied a multi-stage stratified random sampling method to recruit participants for serological tests of rubella. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Immunoglobulin G (IgG) antibodies against rubella in serum samples. Univariate and multivariate analyses are used to detect the association between the level of rubella IgG and related factors. The incidence of rubella cases per million population decreased from 15.8 in 2009 to .1 in 2020. The proportion of rubella cases in women of childbearing age was higher than in men. A total of 4,362 subjects were tested serologically for rubella. The percentage of people whose rubella IgG antibody titers were above the minimum protective level (20 IU/ml) was 80.60% (95% CI: 79.4%–81.8%) and the geometric mean concentration (GMC) for rubella IgG was 58.34 IU/ml. The data indicated that Hangzhou had made good progress toward the elimination of rubella, whereas women of childbearing age still had a higher proportion of rubella cases, which might lead to increased risk of subsequent CRS. The positive rate and GMC of rubella IgG were significantly influenced by age and immunization history of RCV. Therefore, we should stress the importance of pushing forward the campaign for supplementary vaccination of rubella in adults