Sociodemographic factors affecting not receiving COVID-19 vaccine in Japan among people who originally intended to vaccinate: a prospective cohort study

BackgroundVaccine hesitancy is a major issue for acquiring herd immunity. However, some individuals may go unvaccinated owing to inhibitory factors other than vaccine hesitancy. If there is even a small number of such people, support is needed for equitable vaccine distribution and acquiring herd immunity. We investigated sociodemographic factors that affected not undergoing COVID-19 vaccination in Japan among individuals who initially had strong intention to vaccinate. MethodsWe conducted this prospective cohort study on workers aged 20-65 years from December 2020 (baseline), to December 2021 using a self-administered questionnaire survey. There were 27,036 participants at baseline and 18,560 at follow-up. We included 6,955 participants who answered yes to this question at baseline: "Would you like to receive a COVID-19 vaccine as soon as it becomes available?" We applied multilevel logistic regression analyses to examine the association between sociodemographic factors and being unvaccinated at follow-up. ResultsIn all, 289 participants (4.2%) went unvaccinated. The odds ratios (ORs) for being unvaccinated were significantly higher for participants aged 30-39 and 40-49 than those aged 60-65 years. Being divorced, widowed, or single, having low income, and having COVID-19 infection experience also had higher ORs. ConclusionsWe found that some participants who initially had strong intention to vaccinate may have gone unvaccinated owing to vaccine side effects and the financial impact of absenteeism due to side effects. It is necessary to provide information repeatedly about the need for vaccination as well as social support to ensure that those who intend to vaccinate are able to do so.

Workplace infection control measures and perceived organizational support during the COVID-19 pandemic in Japan: a prospective cohort study

ObjectiveWe investigated whether workplace infection control measures during the COVID-19 pandemic could increase perceived organizational support (POS). MethodsThis prospective cohort study was conducted in Japan from December 2020 to December 2021 using a questionnaire survey. There were 18,560 respondents at follow-up; we investigated 4,971 who rated low POS at baseline. The participants were asked a single question about POS and nine about workplace infection control measures. We determined the odds ratios (ORs) of high POS at follow-up using multilevel logistic regression analysis. ResultsThe groups of 5-6 (OR=1.29; 95% confidence interval [CI], 1.05-1.57; P=0.014) and 7-9 workplace infection control measures (OR=1.54; 95% CI, 1.28-1.85; P<0.001) had significantly higher ORs than the group with 0-2 measures. ConclusionsHealth support for employees through workplace infection control measures can increase POS.

COVID-19 vaccination coverage by company size and the effects of socioeconomic factors and workplace vaccination in Japan: a cohort study

BackgroundVaccination is considered the most effective control measure against COVID-19. Vaccine hesitancy and equitable vaccine allocation are important challenges to disseminating developed vaccines. To promote COVID-19 vaccination coverage, the government of Japan established the workplace vaccination program. However, while it appears that the program was effective in overcoming vaccine hesitancy, the program may have hindered the equitable allocation of vaccines because it mainly focused on employees of large companies. We investigated the relationship between company size and COVID-19 vaccination completion status of employees and the impact of the workplace vaccination program on this relationship. MethodsWe conducted an internet-based prospective cohort study from December 2020 (baseline) to December 2021. The data were collected using a self-administered questionnaire survey. Briefly, 27,036 workers completed the questionnaire at baseline and 18,560 at follow-up. After excluding ineligible respondents, we finally analyzed the data from 15,829 participants. At baseline, the participants were asked about the size of the company they worked for, and at follow-up they were asked about the month in which they received their second COVID-19 vaccine dose and the availability of a company-arranged vaccination opportunity. ResultsIn each month throughout the observation period, the odds of having received a second COVID-19 vaccine dose were significantly lower for small-company employees than for large-company employees in the sex- and age-adjusted model. This difference decreased after adjusting for socioeconomic factors, and there was no significant difference after adjusting for the availability of a company-arranged vaccination opportunity. ConclusionsThe workplace vaccination program implemented in Japan to control the COVID-19 pandemic may have been effective in overcoming vaccine hesitancy in workers; however, it may have caused an inequitable allocation of vaccines between companies of different sizes. Because people who worked for small companies were less likely to be vaccinated, it will be necessary to enhance support of vaccination for this population in the event of future infectious disease outbreaks. Trial registrationNot applicable.

Association between willingness to receive the COVID-19 vaccine and sources of health information among Japanese workers: a cohort study

BACKGROUND@#It is important to achieve herd immunity by vaccinating as many people as possible to end the COVID-19 pandemic. We investigated the relationship between willingness to receive vaccination and sources of health information among those who did not want to be vaccinated against COVID-19.@*METHODS@#This prospective cohort study collected data using a self-administered questionnaire survey. The baseline survey was conducted during December 22-25, 2020, and the follow-up survey during February 18-19, 2021. Participants were aged 20-65 years and worked at the time of the baseline survey (N = 33,087). After excluding 6,051 invalid responses, we included responses from 27,036 participants at baseline. In total, 19,941 people responded to the follow-up survey (74% follow-up rate). We excluded 7,415 participants who answered "yes" to the question "If a COVID-19 vaccine becomes available, would you like to get it?" in the baseline survey. We finally analyzed 12,526 participants.@*RESULTS@#The odds ratio for change in willingness to be vaccinated from "no" to "yes" differed by source of health information. Compared with workers that used TV as a source of information, significantly fewer people who reported getting information from the Internet and friends/colleagues were willing to get the vaccine.@*CONCLUSIONS@#It is important to approach workers who do not watch TV when implementing workplace vaccination programs. It is likely that willingness to be vaccinated can be increased through an active company policy whereby the top management recommend vaccination, coupled with an individual approach by occupational health professionals.@*TRIAL REGISTRATION@#Not applicable.

Sociodemographic factors and self-restraint from social behaviors during the COVID-19 pandemic in Japan: a cross-sectional study

The control of human flow has led to better control of COVID-19 infections. Japans state of emergency, unlike other countries, is not legally binding but is rather a request for individual self-restraint; thus, factors must be identified that do not respond to self-restraint, and countermeasures considered for those factors to enhance its efficacy. We examined the relationship between sociodemographic factors and self-restraint toward going out in public during a pandemic in Japan. This cross-sectional study used data for February 18-19, 2021, obtained from an internet survey; 19,560 participants aged 20-65 were included in the analysis. We identified five relevant behaviors: (1) taking a day trip; (2) eating out with five people or more; (3) gathering with friends and colleagues; (4) shopping for other than daily necessities; (5) shopping for daily necessities. Multilevel logistic regression analyses were used to examine the association between sociodemographic factors and self-restraint for each of the behaviors. Results showed that for behaviors other than shopping for daily necessities, women, those aged 60-65, married people, highly educated people, high-income earners, desk workers and those who mainly work with interpersonal communication, and those with underlying disease reported more self-restraint. Older people had less self-restraint than younger people toward shopping for daily necessities; an underlying disease had no effect on the identified behavior. Specialized interventions for these groups that include recommendations for greater self-restraint may improve the efficacy of the implementing measures that request self-restraint.

Effect of familiarity with COVID-19 infection--history of infection or close contact--on outing behaviors when a state of emergency is declared

BackgroundRestricting the movement of the public to gathering places and limiting close physical contact are effective measures against COVID-19 infection. In Japan, states of emergency have been declared in specific prefectures to reduce public movement and control COVID-19 transmission. We investigated how COVID-19 infection related experiences including people with a history of infection, people with a history of close contact, and people whose acquaintances have been infected, affected self-restraint related to outing behaviors during the second state of emergency in Japan. MethodsA prospective cohort study was conducted among workers aged 20-65 years using data from an internet survey. The baseline survey was conducted on December 22-25, 2020, and a follow-up survey was on February 18-19, 2021. There were 19,941 participants who completed both surveys and were included in the final analysis. We identified eight outing behaviors: (1) eating out (4 people or fewer); (2) eating out (5 people or more); (3) gathering with friends and colleagues; (4) day trip; (5) overnight trip (excluding visiting home); (6) visiting home; (7) shopping for daily necessities; and (8) shopping for other than daily necessities. We set self-restraint regarding each outing behavior after the second state of emergency was declared in January 2021 as the dependent variable, and COVID-19 infection related experiences as independent variables. Odds ratios were estimated using multilevel logistic regression analyses. ResultsSignificant differences by COVID-19 infection related experiences were identified: compared to people without COVID-19 related experiences, people with a history of COVID-19 were less likely self-restraint from most outing behaviors. People whose acquaintance had been diagnosed with COVID-19 were significantly more likely to refrain from most outing behaviors. There was no significant difference in any outing behaviors for people with a history of close contact only. ConclusionsTo maximize the effect of a state of emergency, health authorities should disseminate information for each person in the target population, taking into account potential differences related to the COVID-19 infection related experiences.

Association between willingness to receive the COVID-19 vaccine and sources of health information among Japanese workers: a cohort study

BackgroundIt is important to achieve herd immunity by vaccinating as many people as possible to end the COVID-19 pandemic. We investigated the relationship between willingness to receive vaccination and sources of health information among those who did not want to be vaccinated against COVID-19. MethodsThis prospective cohort study collected data using a self-administered questionnaire survey. The baseline survey was conducted during December 22-25, 2020, and the follow-up survey during February 18-19, 2021. Participants were aged 20-65 years and worked at the time of the baseline survey (N = 33,087). After excluding 6,051 invalid responses, we included responses from 27,036 participants at baseline. In total, 19,941 people responded to the follow-up survey (74% follow-up rate). We excluded 7,415 participants who answered "yes" to the question "If a COVID-19 vaccine becomes available, would you like to get it?" in the baseline survey. We finally analyzed 12,526 participants. ResultsThe odds ratio for change in willingness to be vaccinated from "no" to "yes" differed by source of health information. Compared with workers that used TV as a source of information, significantly fewer people who reported getting information from the Internet and friends/colleagues were willing to get the vaccine. ConclusionsIt is important to approach workers who do not watch TV when implementing workplace vaccination programs. It is likely that willingness to be vaccinated can be increased through an active company policy whereby the top management recommend vaccination, coupled with an individual approach by occupational health professionals. Trial registrationNot applicable.

How are sociodemographic factors and risk preferences associated with seasonal influenza vaccination behavior under the COVID-19 pandemic?

The 2020/2021 seasonal influenza vaccination was carried out under unique situations during the coronavirus disease 2019 (COVID-19) pandemic. Examining the factors affecting vaccine inoculation in a pandemic situation may provide valuable insights. The purpose of the current study was to investigate how the COVID-19 pandemic affected the 2020/2021 seasonal influenza vaccine intake. A cross-sectional study was conducted on workers aged 20-65 years on December 22-25, 2020, using data from an Internet survey. We set the presence or absence of 2020/2021 seasonal influenza vaccination as the dependent variable, and each aspect of sociodemographic factors, including gender, age, marital status, education, annual household income, and underlying disease, as independent variables. We performed a multilevel logistic regression analysis nested by residence. In total, 26,637 respondents (13,600 men, 13,037 women) participated, and a total of 11,404 individuals (42.8%) received the 2020/2021 influenza vaccine. Significantly more women than men were vaccinated, and the vaccination rate was higher among younger adults, married people, highly educated people, high-income earners, and those with underlying disease. The current results suggested that the relationship between seasonal influenza vaccination behavior and sociodemographic factors differed from the results reported in previous studies in terms of age. These findings suggest that, during the COVID-19 pandemic, young people may have become more aware of the risk of contracting influenza and of the effectiveness of the influenza vaccine. In addition, information interventions may have had a positive effect.