1.COVID-19 vaccine acceptance among kidney transplant recipients in Singapore.
Ian Tatt LIEW ; Hanis Abdul KADIR ; Sobhana THANGARAJU ; Quan Yao HO ; Eleanor NG ; Fiona FOO ; Terence KEE
Singapore medical journal 2025;66(2):73-80
INTRODUCTION:
A successful vaccination programme forms the cornerstone of controlling coronavirus disease 2019 (COVID-19). The unprecedented speed of COVID-19 vaccine development and lack of long-term data have raised fears regarding its safety and efficacy. Vaccine hesitancy can undermine the uptake, and hence success of the vaccination programme. Given the high complication rates of COVID-19 infections in kidney transplant recipients, it is particularly important to identify and address vaccine hesitancy in this population.
METHODS:
We conducted a cross-sectional survey among kidney transplant recipients attending transplant clinic between 5 April and 5 May 2021. The survey assessed attitudes towards COVID-19, willingness/hesitancy towards COVID-19 vaccination, vaccination concerns and prompts to vaccination. This was scored on a Likert scale with scores ranging from 'strongly disagree' - 1 point to 'strongly agree' - 5 points.
RESULTS:
One hundred and one completed responses were captured. Of these, 86% respondents reported to agree or strongly agree to vaccination. This was despite significant concerns of allograft rejection (mean score 4.12, standard deviation [SD] 0.97) and decreased immunosuppressant efficacy (mean score 4.14, SD 0.96) with vaccination. Multivariable model showed a positive association with transplant vintage of ≥ 5 years (median 2.41), lower educational levels of secondary school or less (median 5.82) and healthcare provider advocacy (median 1.88) in predicting vaccine acceptance.
CONCLUSIONS
Vaccine acceptance rate was high among kidney transplant recipients. Vaccine hesitancy remains a concern in those with a transplant vintage of less than 5 years and those with tertiary educational level. Healthcare provider advocacy is important in improving vaccine acceptance rates.
Humans
;
Kidney Transplantation
;
Singapore/epidemiology*
;
Male
;
Cross-Sectional Studies
;
Female
;
COVID-19 Vaccines
;
COVID-19/epidemiology*
;
Middle Aged
;
Adult
;
Transplant Recipients/psychology*
;
Patient Acceptance of Health Care/statistics & numerical data*
;
Vaccination Hesitancy/psychology*
;
Surveys and Questionnaires
;
Vaccination/psychology*
;
Aged
;
SARS-CoV-2
2.Omicron SARS-CoV-2 outcomes in vaccinated individuals with heart failure and ischaemic heart disease.
Liang En WEE ; Enoch Xueheng LOY ; Jue Tao LIM ; Yew Woon CHIA ; Shir Lynn LIM ; Jonathan YAP ; Khung Keong YEO ; Derek J HAUSENLOY ; Mark Yan Yee CHAN ; David Chien Boon LYE ; Kelvin Bryan TAN
Annals of the Academy of Medicine, Singapore 2025;54(5):270-282
INTRODUCTION:
Outcomes after SARS-CoV-2 Omicron infection in patients with heart failure (HF) and ischaemic heart disease (IHD) remain poorly defined.
METHOD:
In a highly vaccinated cohort of adult Singapore citizens and permanent residents, we used Cox proportional hazards models (adjusted for sociodemographic variables and comorbidities) to compare the risks of Omicron infection, COVID-19- related hospitalisation, and severe COVID-19 between indivi-duals with HF or IHD and matched controls without these conditions.
RESULTS:
From national databases, we identified 15,426 HF patients matched 1:∼3 to 41,221 controls, and 110,442 IHD patients matched 1:∼2 to 223,843 controls. Over 80% of HF and IHD patients had received at least 3 vaccine doses. During the Omicron-predominant period, both HF and IHD cohorts demonstrated higher adjusted risks of COVID-19 hospitalisation compared with matched controls (HF: adjusted hazard ratio [aHR] 1.77, 95% confidence interval [CI] 1.65-1.90; IHD: aHR 1.21, 95% CI 1.17-1.26). Among those with at least 1 HF-or IHD-related admission in the prior year, hospitalisation risk was further elevated (HF: aHR 1.27, 95% CI 1.13-1.42; IHD: aHR 1.11, 95% CI 1.01-1.23). Receipt of ≥3 vaccine doses was associated with substantially lower risk of severe COVID-19 versus only 2 doses (HF: aHR 0.35, 95% CI 0.28-0.43; IHD: aHR 0.27, 95% CI 0.23-0.32). A fourth dose conferred additional reductions in infection and adverse outcomes, though CIs for infection overlapped with those for 3 doses.
CONCLUSION
During Omicron predominance, HF and IHD patients experienced greater risk of COVID-19 hospitalisation and severe COVID-19 versus matched controls. Booster vaccinations attenuated these risks. Individuals with recent HF/IHD admissions should be prioritised for receipt of booster vaccine doses.
Humans
;
COVID-19/complications*
;
Male
;
Heart Failure/complications*
;
Myocardial Ischemia/complications*
;
Female
;
Middle Aged
;
Hospitalization/statistics & numerical data*
;
Aged
;
COVID-19 Vaccines/administration & dosage*
;
Singapore/epidemiology*
;
SARS-CoV-2
;
Proportional Hazards Models
;
Adult
;
Case-Control Studies
;
Vaccination/statistics & numerical data*
3.Differences in routine childhood immunization uptake between single and multiple healthcare facility use: the Kochi Adjunct Study of Japan Environment and Children's Study.
Marina MINAMI ; Yoshihiko TERAUCHI ; Masamitsu EITOKU ; Yuki SHIMOTAKE ; Tamami TSUZUKI ; Ryuhei NAGAI ; Nagamasa MAEDA ; Mikiya FUJIEDA ; Narufumi SUGANUMA
Environmental Health and Preventive Medicine 2025;30():51-51
BACKGROUND:
The efficacy of routine childhood immunization depends on timely vaccine uptake and facility use patterns. This study examined the association between pediatric vaccination facility use patterns and routine childhood immunization uptake among children up to age eight years.
METHODS:
As part of the Kochi Adjunct Study of the Japan Environment and Children's Study (JECS), we analyzed data from 1,644 participants whose Maternal and Child Health Handbook photographs were collected in the eighth year of the cohort study. Maternal and Child Health Handbook records determined immunization completion. Participants were categorized into four groups based on pediatric vaccination facility use patterns: single facility use throughout, multiple facility use during the first period, multiple facility use during the second period, and multiple facility use throughout both periods. Maternal and child characteristics were collected via paper-based questionnaires. Associations between facility use patterns, sociodemographic factors, and immunization completion were analyzed using chi-square tests and logistic regression.
RESULTS:
Overall, routine childhood immunization completion was observed in 1,259 (76.6%) participants. Chi-square tests indicated that marital status, educational level, lower parity, never smoking, not attending nursery, and breastfeeding practice for infants aged four months old were significantly associated with routine childhood immunization completion. Single facility use throughout the immunization period was observed in 1,011 (61.5%) participants. Multiple facility use (38.5%) was associated with higher odds of routine childhood immunization incompletion than single facility use. This association was the strongest for those who used multiple facilities throughout the vaccination period (adjusted odds ratio, 1.90; 95% confidence interval, 1.24-2.91).
CONCLUSIONS
Single pediatric facility use was associated with higher routine immunization uptake. Our findings suggest that encouraging the use of one medical institution for a child's vaccinations may be a useful approach to consider when addressing vaccination coverage challenges.
Humans
;
Japan
;
Female
;
Male
;
Infant
;
Child, Preschool
;
Health Facilities/statistics & numerical data*
;
Child
;
Vaccination/statistics & numerical data*
;
Adult
;
Immunization/statistics & numerical data*
;
Cohort Studies
;
Infant, Newborn
4.Estimated coverage of vaccines for children in Japan between 2011 and 2022: a descriptive study utilizing nationwide monthly market data.
Environmental Health and Preventive Medicine 2025;30():79-79
BACKGROUND:
Japan lacks comprehensive reports on the nationwide voluntary vaccine coverage. The effectiveness of public subsidies in promoting vaccination has not been fully investigated. Therefore, we aimed to estimate the nationwide coverage of voluntary vaccines, compare it with that of national immunization program (NIP)-included vaccines, and investigate the effectiveness of public subsidies.
METHODS:
We obtained nationwide monthly vaccine market data for rotavirus, Haemophilus influenzae type b (Hib), diphtheria, tetanus toxoid, acellular pertussis, inactivated poliovirus (DTaP-IPV), and mumps vaccines; estimated recipient numbers; and calculated coverage as the proportion of children from October 2011 to March 2022. Regarding the NIP-included vaccine, we compared vaccine coverage calculated from nationwide annual market data with that estimated by World Health Organization (WHO)/United Nations Children's Fund (UNICEF), using Bland-Altman analysis.
RESULTS:
The estimates of Hib and DTaP-IPV vaccine coverage derived from market data were slightly higher than the WHO/UNICEF estimates, with mean differences of 0.05 (95% CI: 0.02-0.07) for Hib and 0.03 (95% CI: 0.01-0.05) for DTaP-IPV. The coverage of the rotavirus vaccine gradually increased long before the implementation of national subsidies, reaching 0.9 in 2020. Hib vaccine coverage had already achieved 1.0 by January 2012. The coverage of the DTaP-IPV vaccine was approximately 0.6-0.8 in 2013, reaching 1.0 in 2014. The coverage of mumps vaccine increased gradually from 2011 to 2021.
CONCLUSIONS
Despite the possibility of overestimation, our estimates may serve as a valuable surrogate for actual vaccine coverage in Japan. An increasing trend in rotavirus and mumps vaccine coverage was observed when these vaccines were categorized as voluntary. Although vaccination policies differ from country to country, it would be beneficial to share findings on the impact of subsidies in Japan with other countries.
Japan
;
Humans
;
Vaccination Coverage/statistics & numerical data*
;
Infant
;
Immunization Programs/statistics & numerical data*
;
Rotavirus Vaccines
;
Haemophilus Vaccines
;
Child, Preschool
;
Poliovirus Vaccine, Inactivated
;
Vaccines
5.National Trends in Influenza Vaccination Rates in South Korea Before and During the COVID-19 Pandemic, 2011-2022.
Kyeongeun KIM ; Kyeongmin LEE ; Yejun SON ; Seoyoung PARK ; Raphael UDEH ; Jiseung KANG ; Hayeon LEE ; Soeun KIM ; Jaeyu PARK ; Hyeon Jin KIM ; Damiano PIZZOL ; Lee SMITH ; Jiyoung HWANG ; Dong Keon YON
Biomedical and Environmental Sciences 2025;38(9):1044-1057
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
6.Factors associated with adults' actions to confirm their own rubella immune status in Japan's drive toward rubella elimination: Cross-sectional online survey of non-healthcare workers in their 20s to 40s.
Masataro NORIZUKI ; Ai HORI ; Koji WADA
Environmental Health and Preventive Medicine 2021;26(1):77-77
BACKGROUND:
Rubella outbreaks occurred among adults in Japan in 2013-2014 and 2018-2019 due to immunity gaps. In response and aiming at rubella elimination by 2020, the government introduced countermeasures comprising supplementary immunization activities for voluntary testing of adult non-healthcare-related workers and vaccination of susceptible individuals. However, as of October 2020, rubella immunity testing and vaccination rates remained low. This study was conducted to identify factors associated with adults voluntarily confirming their rubella immune status, to help develop effective promotion activities for hard-to-reach and left-behind populations.
METHODS:
In this cross-sectional study, a general population sample of non-healthcare workers aged 20-49 years in Japan completed an online survey in November 2020. Univariate analysis was performed to examine associations of specific actions taken to confirm rubella immune status with social background characteristics, knowledge of rubella, and attitude to testing and vaccination. Log binomial regression analysis was performed to explore the associations following adjustment for social background characteristics.
RESULTS:
Among 1,854 respondents (927 men, 927 women), only 23.4% of men and 39.4% of women in their 20s to 40s have taken some action related to rubella prevention. Three major factors were associated with the targeted population having taken voluntary action: (1) knowing about testing for confirmation of immunity status (adjusted odds ratio [AOR] 4.29 men, 2.89 women), the rubella outbreak in 2013 among men in their 20s to 40s (AOR 2.79 men, 1.64 women), and congenital rubella syndrome (AOR 1.89 men, 3.10 women); (2) having acquaintances who were vaccinated against or tested for rubella (AOR 2.98 men, 1.95 women); and (3) having a positive attitude toward influenza vaccination (AOR 2.48 men, 1.83 women). Marriage, desire for pregnancy, and having children were weakly associated with taking action.
CONCLUSIONS
Currently, insufficient voluntary action is being taken by high-risk adult populations to close the identified immunity gaps. In this last mile to rubella elimination, our findings and suggested potential interventions via annual health check-ups and occupational health and public health initiatives could prove helpful in developing further countermeasures that actively promote and implement supplementary immunization activities targeting all adult generations.
Adult
;
Cross-Sectional Studies
;
Female
;
Health Knowledge, Attitudes, Practice
;
Humans
;
Japan
;
Male
;
Middle Aged
;
Rubella/prevention & control*
;
Vaccination/statistics & numerical data*
;
Young Adult
7.Modeling the Long-term Antibody Response and Duration of Immune Protection Induced by an Inactivated, Preservative-free Hepatitis A Vaccine (Healive) in Children.
Yong Pei YU ; Jiang Ting CHEN ; Zhi Wei JIANG ; Ling WANG ; Cheng Kai YU ; Xiao Yan YAN ; Chen YAO ; Jie Lai XIA
Biomedical and Environmental Sciences 2020;33(7):484-492
Objective:
Long-term seroprotection the hepatitis A vaccine is essential for the prevention of disease from the hepatitis A virus (HAV). Due to documented difficulties during decade-long follow-ups after receiving vaccines, statistical-modeling approaches have been applied to predict the duration of immune protection.
Methods:
Based on five-year follow-up data from a randomized positive-controlled trial among Chinese children (1-8 years old) following a 0, 6 months vaccination schedule, a power-law model accounting for the kinetics of B-cell turnover, as well as a modified power-law model considering a memory-B-cell subpopulation, were fitted to predict the long-term immune responses induced by HAV vaccination (Healive or Havrix). Anti-HAV levels of each individual and seroconversion rates up to 30 years after vaccination were predicted.
Results:
A total of 375 participants who completed the two-dose vaccination were included in the analysis. Both models predicted that, over a life-long period, participants vaccinated with Healive would have close but slightly higher antibody titers than those of participants vaccinated with Havrix. Additionally, consistent with previous studies, more than 90% of participants were predicted to maintain seroconversion for at least 30 years. Moreover, the modified power-law model predicted that the antibody titers would reach a plateau level after nearly 15 years post-vaccination.
Conclusions
Based on the results of our modeling, Healive may adequately induce long-term immune responses following a 0, 6 months vaccination schedule in children induction of memory B cells to provide stable and durable immune protection.
Adolescent
;
Child
;
Child, Preschool
;
China
;
Female
;
Hepatitis A
;
immunology
;
Hepatitis A Antibodies
;
blood
;
Hepatitis A Vaccines
;
administration & dosage
;
Humans
;
Immunity, Active
;
Infant
;
Male
;
Models, Statistical
;
Vaccination
;
statistics & numerical data
8.The Influence of Mothers' Native Country on Multicultural Adolescents' Seasonal Influenza Vaccinations in Multicultural Adolescents Using Data from the 13th (2017) Korea Youth Risk Behavior Web-Based Survey.
Mi Young KWON ; Sookyung JEONG
Child Health Nursing Research 2018;24(2):148-156
PURPOSE: The aim of this study was to evaluate the influence of the mothers' native country on influenza vaccinations in adolescents in multicultural families. METHODS: Data were gathered from the 13th (2017) Youth Risk Behavior Web-Based Survey. Logistic regression analyses were conducted using a complex sample data analysis method. The participants in this study had a father who was born in Korea and a mother born outside of Korea. The sample included 481 adolescents. RESULTS: The analysis of non-adjusted confounding variables showed that influenza vaccination was higher in multicultural adolescents whose mother's native country had an annual minimum temperature less than 21℃ (odds ratio [OR]: 1.81, 95% confidence interval [CI]: 1.20~2.74). Furthermore, when the analysis was adjusted for confounding variables, an annual minimum temperature less than 21℃ in the mother's native country had a statistically significant association with influenza vaccination (OR: 2.12, 95% CI: 1.36~3.29). CONCLUSION: Multicultural adolescents belong to a socioeconomically vulnerable class, and their health promotion behaviors are influenced by their mothers' culture. Thus, healthcare providers and school nurses should provide adolescents with appropriate information related to influenza vaccination depending on their mothers' culture and their family's cultural background.
Adolescent*
;
Confounding Factors (Epidemiology)
;
Cultural Diversity
;
Emigrants and Immigrants
;
Fathers
;
Health Personnel
;
Health Promotion
;
Humans
;
Influenza Vaccines
;
Influenza, Human*
;
Korea*
;
Logistic Models
;
Methods
;
Mothers
;
Risk-Taking*
;
Seasons*
;
Statistics as Topic
;
Vaccination*
9.Epidemiology of human rabies in China, 2016.
Yan Rong LI ; Li Ling ZHU ; Wu Yang ZHU ; Xiao Yan TAO
Chinese Journal of Epidemiology 2018;39(1):40-43
Objective: To understand the epidemiological characteristics of human rabies in China in 2016 and provide evidence for the control and prevention of human rabies. Methods: The incidence data of human rabies in China in 2016 were collected from national infectious disease reporting information management system. The surveillance data were collected from provinces of Shandong, Guizhou, Anhui, Hunan, Jiangsu and Guangxi Zhuang Autonomous Region. Excel 2013 software was used to process and summarize the data, the epidemiological characteristics of human rabies in China in 2016 were described by using indicators such as morbidity, mortality and constituent ratio. Results: A total of 644 human rabies cases were reported in 28 provinces in China in 2016, a decrease of 19.60% (157/801) compared with 2015. The provinces reporting high incidences of human rabies were Henan, Hunan, Guangxi and Guizhou, accounting for 39.44% (254/644) of the total cases. One case was reported in Qinghai province and Xinjiang Uygur Autonomous Region respectively. The male to female ratio of the cases was 2.14∶1 (439/205), and the majority of the patients were farmers (444/644). Surveillance points in 6 provinces reported 1 281 340 persons seeking post-exposure treatment, of whom 1 018 367 were treated for dog bite or scratch. A total of 764 234 persons completed the vaccination series, accounting for 63.90% (764 234/1 195 956) of the persons with grade Ⅱ and Ⅲ exposures, and 28.89% (165 677/573 571) of the persons with grade Ⅲ exposure were treated with passive immunization product. The average density of dogs in each surveillance area was 7.03/100 persons, the average canine immunization rate was 37.64%. Conclusion: The incidence of human rabies has remained decline in China in 2016, the number of the affected provinces has increased and that has the tendency of spreading to low-risk regions. The cases mainly occurred in men and farmers, and caused by dog bite or scratch. It is necessary to strengthen the health education about rabies prevention and control in rural areas and expand the coverage of canine immunization to prevent and control human rabies.
Animals
;
China/epidemiology*
;
Disease Notification/statistics & numerical data*
;
Dogs
;
Female
;
Health Education
;
Humans
;
Incidence
;
Male
;
Post-Exposure Prophylaxis
;
Rabies/ethnology*
;
Rabies Vaccines
;
Sentinel Surveillance
;
Vaccination
10.Effect of influenza and 23-valent pneumococcal polysaccharide vaccinations on elderly with chronic obstructive pulmonary diseases: a community-based intervention study.
Y WEN ; L HE ; Y ZHAI ; J WU ; Y Y CHEN ; H WANG ; Q Q ZONG ; X F LIANG
Chinese Journal of Epidemiology 2018;39(6):792-798
Objective: To explore the effect of influenza and 23 valent pneumococcal polysaccharide pneumococcal vaccinations on symptom-improvement among elderly with chronic obstructive pulmonary diseases (COPD). Methods: Data was gathered from 4 communities in 3 National Demonstration Areas set for comprehensive prevention and control of chronic non- communicable diseases in Chongqing city and Ningbo city respectively, from November 2013 to October 2014. The communities were selected by cluster sampling and divided into 4 groups: (1) injected influenza vaccines; (2) injected with pneumococcal vaccines; (3) received both of the two vaccines; (4) the control group that without any intervention measures. All the subjects aged from 60 to 75 were selected to fill in demographic information questionnaire and receive (COPD assessment test, CAT) scores twice, before intervention and 1 year after the vaccination. SAS 9.4 software was used to analyze the change of symptoms and CAT scores before and after the intervention program and comparing the improvement on symptoms among the elderly people under study. Results: A total of 1 244 subjects with nearly same baseline conditions after the propensity score matching, were involved in this study. CAT scores appeared as Median=21 (IQR: 17-26) at baseline. The CAT scores appeared as Median=18 (IQR: 14-24), decreasing in all the 3 vaccinated groups, one year after the intervention program (influenza vaccines, matching t test, t=-6.531, P=0.403; pneumococcal vaccines, Wilcoxon test, H=-9 623, P<0.001; combined vaccine vaccines, matching t test, t=-10.803, P<0.001). However, in the control group, no obvious change was observed (Wilcoxon H=1 167, P=0.403). Proportions of impacts at high or very high levels all decreased in the 3 intervention groups, while little change was observed in the control group. Outcomes from the Factorial analysis suggested that influenza vaccination could improve the general conditions and symptoms including cough, chest tightness, dyspnea, physical activities, and stamina. Pneumococcal vaccination appeared more effective on all of symptoms and indicators. Conclusion: Pneumococcal and influenza vaccination seemed helpful for elderly people suffering COPD to improve the general health condition.
Aged
;
Humans
;
Influenza Vaccines/immunology*
;
Influenza, Human
;
Pneumococcal Vaccines/immunology*
;
Pneumonia, Pneumococcal/prevention & control*
;
Pulmonary Disease, Chronic Obstructive/complications*
;
Streptococcus pneumoniae
;
Surveys and Questionnaires
;
Vaccination/statistics & numerical data*
;
Vaccine Potency

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