National seroepidemiological study of COVID-19 after the initial rollout of vaccines: Before and at the peak of the Omicron-dominant period in Japan.
Influenza Other Respir Viruses
; 17(2): e13094, 2023 02.
Article
em En
| MEDLINE
| ID: mdl-36824391
ABSTRACT
Background:
Based on routine surveillance data, Japan has been affected much less by COVID-19 compared with other countries. To validate this, we aimed to estimate SARS-CoV-2 seroprevalence and examine sociodemographic factors associated with cumulative infection in Japan.Methods:
A population-based serial cross-sectional seroepidemiological investigation was conducted in five prefectures in December 2021 (pre-Omicron) and February-March 2022 (Omicron [BA.1/BA.2]-peak). Anti-nucleocapsid and anti-spike antibodies were measured to detect infection-induced and vaccine/infection-induced antibodies, respectively. Logistic regression was used to identify associations between various factors and past infection.Results:
Among 16 296 participants (median age 53 [43-64] years), overall prevalence of infection-induced antibodies was 2.2% (95% CI 1.9-2.5%) in December 2021 and 3.5% (95% CI 3.1-3.9%) in February-March 2022. Factors associated with past infection included those residing in urban prefectures (Tokyo aOR 3.37 [95% CI 2.31-4.91], Osaka aOR 3.23 [95% CI 2.17-4.80]), older age groups (60s aOR 0.47 [95% CI 0.29-0.74], 70s aOR 0.41 [95% CI 0.24-0.70]), being vaccinated (twice aOR 0.41 [95% CI 0.28-0.61], three times aOR 0.21 [95% CI 0.12-0.36]), individuals engaged in occupations such as long-term care workers (aOR 3.13 [95% CI 1.47-6.66]), childcare workers (aOR 3.63 [95% CI 1.60-8.24]), food service workers (aOR 3.09 [95% CI 1.50-6.35]), and history of household contact (aOR 26.4 [95% CI 20.0-34.8]) or non-household contact (aOR 5.21 [95% CI3.80-7.14]) in February-March 2022. Almost all vaccinated individuals (15 670/15 681) acquired binding antibodies with higher titers among booster dose recipients.Conclusions:
Before Omicron, the cumulative burden was >10 times lower in Japan (2.2%) compared with the US (33%), the UK (25%), or global estimates (45%), but most developed antibodies owing to vaccination.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacinas
/
COVID-19
Tipo de estudo:
Observational_studies
/
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Aged
/
Humans
/
Middle aged
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article