Impact of COVID-19 vaccination by implementation timing and coverage rate in relation to misinformation prevalence in Japan

COVID-19 vaccines have saved many lives during the pandemic. However, the implementation strategy of vaccination in some countries may not have been ideal. In this study, we investigated the impact of vaccination on COVID-19 mortality in counterfactual scenarios for different vaccine implementation timings and coverage in Japan. To do so, we developed a mathematical model to predict the number of COVID-19 deaths using weekly data on COVID-19 cases, vaccination coverage, vaccine effectiveness, and the proportion of SARS-CoV-2 variants. We also reanalyzed survey data from our previous study about the prevalence of misinformation beliefs and attitudes toward COVID-19 vaccination, in order to build counterfactual scenarios in which we had managed misinformation better or worse. In Japan, the COVID-19 death toll was 14,994 in 2021 before the emergence of the Omicron variant in December. Counterfactual scenario simulations using the mathematical model revealed that 30,117 deaths were averted by vaccination in 2021, considering the direct and indirect effects of vaccines. If we had failed to manage the influence of misinformation, vaccination coverage would have dropped from 83.4 % to 76.6 %. And there would have been 1020 more deaths. The death toll could have decreased by 431 in a scenario for better misinformation management, assuming vaccination coverage of 88.0 %. Three-month delayed vaccination implementation would have increased the death toll by 22,216, whereas three-month early implementation would have averted 7003 deaths. Therefore, implementation timing had a stronger effect than vaccination coverage. This study highlights the importance of assessing vaccination strategies from the perspective of misinformation management and timing to start vaccination rollout.Vaccine, 59, art. no. 127273; 2025journal articl

The spread of heated tobacco product (HTP) use across various subgroups during 2015-16 and 2017-18 in Japan

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Tobacco Advertising During the COVID-19 Pandemic in Japan

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The Impact of Priority Settings at the Start of COVID-19 Mass Vaccination on Subsequent Vaccine Uptake in Japan: One-Year Prospective Cohort Study

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Nicotine dependence based on the tobacco dependence screener among heated tobacco products users in Japan, 2022-2023: The JASTIS study

Heated tobacco products (HTPs) are nicotine-containing products similar to cigarettes and are widely used in Japan. However, there has been insufficient research on nicotine dependence associated with HTP use. This study investigated the association of the types of individuals who smoked with the prevalence of nicotine dependence. We utilized data from the Japan Survey on Tobacco and Health (JASTIS). A total of 7969 participants who currently smokes was selected from the 2022 and 2023 survey respondents for the analysis. Nicotine dependence was defined as a score of 5 or higher on the Tobacco Dependence Screener (TDS). The prevalence of nicotine dependence was 43.0% (3473/8077) among all participants who smoked, 42.9% (1479/3447) among those who used cigarettes, 44.2% (760/1720) among those who used two products, and 43.0% (1206/2802) among those who used HTPs. The prevalence of nicotine dependence was statistically higher in the participants who used two products than in cigarettes (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.04-1.33). When classified by temperature, participants who used of two products (high-temp and low-temp) and those using participants who used HTPs (high-temp) had higher ORs for prevalent nicotine dependence (OR, 1.31 [95% CI, 1.14-1.51]) and (OR, 1.12 [95% CI, 1.00-1.25], respectively) compared to participants who used cigarettes. Additionally, the ORs for prevalent nicotine dependence increased with the number of tobacco sticks smoked per day. These results suggest that HTP use, particularly high-temperature HTPs use, and a higher number of tobacco sticks smoked is associated with nicotine dependence

Married women’s decision to delay childbearing, and loneliness, severe psychological distress, and suicidal ideation under crisis: online survey data analysis from 2020 to 2021

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Stroke and Ischemic Heart Disease among LGBT Sexual and Gender Minorities in Japan

Leading causes of death in Japan include stroke and ischemic heart disease (IHD). It has been unclear regarding risk for these diseases among sexual and gender minorities (SGMs) in Japan. Using cross-sectional data from JACSIS (Japan COVID-19 and Society Internet Survey) 2022, participants were categorized in cisgender/heterosexual, lesbian, gay, bisexual and transgender based on sex at birth, gender identity and sexual orientation. Outcome was measured by past history of stroke or IHD. Multivariable logistic regression was constructed adjusting for risk factors. 24,298 participants were eligible for analysis. Overweight/obesity was prevalent among gay and bisexual participants, while lesbians and transgenders were implausible compared to cisgender/heterosexuals. After adjusting for potential covariates, all SGM groups experienced increased prevalence of stroke (transgender odds ratio [OR], 2.97; 95% CI, 1.74-5.06, gay OR, 2.69; 95%CI, 2.00-3.64, lesbian OR, 2.44; 95%CI, 1.0-3.40, bisexual OR, 1.86; 95% CI, 1.01-3.40) and IHD (transgender OR, 2.92; 95%CI, 1.75-4.86, gay OR, 2.18; 95%CI, 1.64-2.91, lesbian OR, 1.96; 95%CI, 1.32-2.93, bisexual OR, 1.23; 95% CI, 0.65-2.31) compared to cisgender/heterosexuals. SGMs in Japan have different prevalence of cardiovascular risk factors compared to Western countries. SGMs face higher prevalence of stroke or IHD, and transgenders were most vulnerable. There is much need in support for the health of SGMs in Japan

Impact of workplace smoke-free policy on secondhand smoke exposure from cigarettes and exposure to secondhand heated tobacco product aerosol during COVID-19 pandemic in Japan: the JACSIS 2020 study

[Objectives] Promoting smoke-free policies is a key intervention for reducing secondhand smoke (SHS) exposure. During the COVID-19 pandemic in Japan, many indoor smoking spaces in workplaces were closed. This study aimed to reveal the association between a workplace smoke-free policy and SHS exposure among non-smoking employees, distinguishing between SHS exposure from cigarettes and exposure to secondhand heated tobacco product (HTP) aerosol, which have recently become popular in Japan. [Design and setting] We used data from the Japan COVID-19 and Society Internet Survey conducted in August–September 2020. [Participants] Among the 25 482 eligible respondents, 8196 non-smoking employees were analysed. [Primary outcome measure] Multivariable logistic regression models were used to examine the impact of smoke-free policies in the workplace. [Results] Compared with complete smoking bans, the ORs and 95% CIs for workplace SHS exposure at least once a week from cigarettes were 2.06 (95% CI: 1.60 to 2.65) for partial bans with no longer available smoking spaces, 1.92 (95% CI: 1.63 to 2.25) for partial smoking bans with still available smoking spaces and 5.33 (95% CI: 4.10 to 6.93) for no smoking bans. The corresponding ORs and 95% CIs for exposure to secondhand HTP aerosol were 4.15 (95% CI: 3.22 to 5.34), 2.24 (95% CI: 1.86 to 2.71) and 3.88 (95% CI: 2.86 to 5.26), respectively. [Conclusions] The effect of partial bans was limited, and temporary closure of smoking spaces might contribute to increased exposure to secondhand HTP aerosol. Complete smoking bans in the workplace were reaffirmed to be the best way to reduce SHS exposure from cigarettes and exposure to secondhand HTP aerosol

The influence of information sources on intention changes to receive COVID-19 vaccination: A prospective cohort study in Japan

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