Acute Adverse Events at a Mass Vaccination Site after the Third and Fourth COVID-19 Vaccinations in Japan.

The third and fourth doses of the vaccine against coronavirus disease 2019 (COVID-19) were widely administered in Japan since December 2021. Currently, however, data are scarce regarding acute adverse events with the third and fourth doses. The present study reports the profiles of acute adverse events after the third and fourth COVID-19 vaccine doses, seen at the site of a mass vaccination center in Japan. Between December 2021 and July 2022, 267,515 individuals received the third, and 32,934 received the fourth COVID-19 vaccine dose at the mass vaccination center, of whom 442 recipients of the third (0.19%), and 22 recipients of the fourth (0.07%) dose reported acute adverse events and were examined by doctors on site. The most common diagnosis was vasovagal syncope/presyncope (incidence: 0.01-0.10%), followed by other miscellaneous complaints, acute allergic reactions (0.05-0.005%), and anaphylaxis (< 0.005%). Vasovagal syncope/presyncope occurred most frequently in recipients in those in their 20s, whereas acute allergic reactions were most frequent in those in their 40s. Both reactions were more frequent in women than men. The peak occurrence of vasovagal syncope/presyncope was earlier than 15 min after the injection, whereas that of acute allergic reaction was later than 15 min after the injection. The incidence of acute allergic reactions appeared to differ between various vaccine manufacturers, whereas that of vasovagal syncope/presyncope did not. These real-world data may benefit the safe and efficient implementation of mass vaccination campaigns for citizens who want to receive COVID-19 vaccines now and in the future.

Reports of acute adverse events in mRNA COVID-19 vaccine recipients after the first and second doses in Japan.

Mass vaccination against coronavirus disease 2019 (COVID-19) is ongoing in many countries worldwide. This study reports the occurrence of acute adverse events among vaccine recipients at a mass vaccination center in Japan. Between August and November 2021, approximately 130,000 individuals received two mRNA vaccine doses (mRNA-1273; Moderna) at the vaccination center. Acute adverse events at the site were observed in 1.1% of the recipients after the first dose and in 0.4% of the recipients after the second dose. The most common event was vasovagal syncope/presyncope, followed by acute allergic reactions. The occurrence rate of vasovagal syncope/presyncope was highest in the young population of those aged 16-29 years, but such age-dependency was not apparent in acute allergic reactions. Both symptoms were more prevalent in women than in men. Vasovagal syncope/presyncope occurred mainly within 20 min of the injection, whereas nearly half of the episodes of acute allergic reactions occurred after 20 min. The vaccine being injected while the recipient was in the supine position effectively reduced the occurrence of vasovagal syncope/presyncope. In summary, the suggested risk factors for vasovagal syncope/presyncope included a young age and female sex. The vaccine being injected while the recipient was in the supine position would reduce the risk of vasovagal syncope/presyncope.

[Trajectory of evacuees' health condition after the Great East Japan Earthquake: Health survey of residents in prefabricated temporary housing and private rented housing in the Miyagi prefecture].

Objectives The Great East Japan Earthquake occurred in March 2011. As of November 2018, 1100 survivors of its still lived in the Miyagi prefecture's temporary housing. Previous studies revealed that the residential relocation to temporary housing from their own houses due to damages caused by the earthquake exacerbated the evacuees' health. However, there is a lack of long-term observation of the trajectory of their health conditions in temporary housing. To the best of our knowledge, there is no study involving residents in public disaster housing. The aim of the present study was to reveal the trajectory of health conditions of residents of temporary and public disaster housing.Method This repeated cross-sectional study included residents aged 20 years and older, residing in private rented housing, prefabricated temporary housing, and public disaster housing. The survey period lasted for six years (2011 to 2017). We used self-rated health as the dependent variable, the year of the survey and type of house as independent variables, and sex and age as covariates. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were calculated using multivariate logistic regression analysis.Results In total, 179,255 participants were included in this study. The average age was the highest among the residents of public disaster housing: 63.0 years in 2017. The number of residents who reported poor self-rated health declined yearly of private rented housing, but not of prefabricated temporary housing. The highest number of residents reporting poor self-rated health was from public disaster housing, compared to other temporary housing. Multivariate analysis showed that self-rated health improved in recent years (P for trend <0.001). Compared to the residents of private rented housing, those from public disaster housing reported poorer health conditions (aOR, 1.20 ; 95% CI, 1.15-1.27), although no significant difference was observed among the residents of prefabricated housing.Conclusion Health conditions of residents of temporary housing and public disaster housing tended to improve on a yearly basis. Residents of public disaster housing reported poor health. Therefore, monitoring and adequate intervention should be offered.