Simulation of future COVID-19 epidemic by vaccination coverage scenarios in Japan

Furuse, Yuki

doi:10.7189/jogh.11.05025

Cited by 15 publications

(19 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The time of spread of each COVID-19 variant was defined with reference to previous studies in Japan [ 9 , 20 , 23 , 24 ]. Of the five waves of the COVID-19 pandemic in Japan, the period from January 16, 2020 to the third wave is the wild type, the fourth wave is the alpha variant, and the fifth wave is the delta variant.…”

Section: Methodsmentioning

confidence: 99%

“…Clarifying the existence of such socioeconomic disparities is important for anti-COVID-19 measures, especially in considering which population groups should be given priority for vaccination [ 6 ]. Although vaccination is an effective means for the prevention of infectious diseases [ 7 ], with regard to COVID-19, preventing the spread of infection by vaccines has not been achieved as expected [ 8 , 9 ]. Therefore, in addition to general preventive measures for infectious disease, other measures to prevent COVID-19 infection among the population are required [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

“…Although the number of public health nurses is considered to be one of the key factors in controlling the spread of COVID-19, we could not find any previous studies reporting that the high number of public health nurses per population was associated with low morbidity of COVID-19. Additionally, in previous studies targeting the Japanese population, it has been reported that the transmissibility of the alpha variant is stronger than that of the original wild-type strain [ 20 , 21 ], and that the transmissibility of the delta variant is stronger than that of the alpha variant [ 9 , 20 ]. Because the transmissibility of COVID-19 increases with each appearance of COVID-19 variants, strategies that were once effective in controlling the spread of COVID-19 may no longer be effective after the emergence of a new variant type [ 9 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, in previous studies targeting the Japanese population, it has been reported that the transmissibility of the alpha variant is stronger than that of the original wild-type strain [ 20 , 21 ], and that the transmissibility of the delta variant is stronger than that of the alpha variant [ 9 , 20 ]. Because the transmissibility of COVID-19 increases with each appearance of COVID-19 variants, strategies that were once effective in controlling the spread of COVID-19 may no longer be effective after the emergence of a new variant type [ 9 , 20 , 21 ]. Although we failed to find previous studies on how COVID-19 variants affect the association between the number of public health nurses and COVID-19 outcomes in Japan, we had the hypothesis that the variant type might affect the relationship between the COVID-19 incidence rate and the number of public health nurses, for example, as new variants emerged, the association would weaken.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Number of public health nurses and COVID-19 incidence rate by variant type: an ecological study of 47 prefectures in Japan

Tomioka

Shima

Saeki

2022

Environ Health Prev Med

View full text Add to dashboard Cite

Background Community health activities by public health nurses (PHNs) are known to improve lifestyle habits of local residents, and may encourage the practice of infectious disease prevention behaviors during the COVID-19 pandemic. We investigated the association between prefecture-level COVID-19 incidence rate and the number of PHNs per population in Japan, by the COVID-19 variant type. Methods Our data were based on government surveys where prefectural-level data are accessible to the public. The outcome variable was the COVID-19 incidence rate (i.e., the cumulative number of COVID-19 cases per 100,000 population for each variant type in 47 prefectures). The explanatory variable was the number of PHNs per 100,000 population by prefecture. Covariates included socioeconomic factors, regional characteristics, healthcare resources, and health behaviors. The generalized estimating equations of the multivariable Poisson regression models were used to estimate adjusted incidence rate ratio (IRR) and 95% confidence interval (CI) for the COVID-19 cases. We performed stratified analyses by variant type (i.e., wild type, alpha variant, and delta variant). Results A total of 1,705,224 confirmed COVID-19 cases (1351.6 per 100,000 population) in Japan were reported as of September 30, 2021. The number of PHNs per 100,000 population in Japan was 41.9. Multivariable Poisson regression models showed that a lower number of PHNs per population was associated with higher IRR of COVID-19. Among all COVID-19 cases, compared to the highest quintile group of the number of PHNs per population, the adjusted IRR of the lowest quintile group was consistently significant in the models adjusting for socioeconomic factors (IRR: 3.76, 95% CI: 2.55–5.54), regional characteristics (1.73, 1.28–2.34), healthcare resources (3.88, 2.45–6.16), and health behaviors (2.17, 1.39–3.37). These significant associations were unaffected by the variant type of COVID-19. Conclusion We found that the COVID-19 incidence rate was higher in prefectures with fewer PHNs per population, regardless of the COVID-19 variant type. By increasing the number of PHNs, it may be possible to contain the spread of COVID-19 in Japan and provide an effective human resource to combat emerging infectious diseases in the future. Supplementary information The online version contains supplementary material available at https://doi.org/10.1265/ehpm.22-00013 .

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Number of public health nurses and COVID-19 incidence rate by variant type: an ecological study of 47 prefectures in Japan

Tomioka

Shima

Saeki

2022

Environ Health Prev Med

View full text Add to dashboard Cite

show abstract

“…(2) Epidemic trend defined by reproduction number of the existing strain (0.67/1.0/1.5). For example in Japan, the effective reproduction number of COVID-19 ranges between 0.5 (under a state of emergency) and 2 (when public health interventions were relaxed) [ 19 ]. (3) The total number of people infected with the existing strain and the novel variant on day 0 (100/500/2500).…”

Section: Methodsmentioning

confidence: 99%

Simulation study reveals factors that affect the predominance of SARS-CoV-2 novel variant

Furuse

2021

Virol J

Self Cite

View full text Add to dashboard Cite

The novel variants of the SARS-CoV-2 are a great global concern for the ongoing COVID-19 pandemic. However, how the novel variants predominate and replace existing strains remains elusive. In this study, I simulated the infection spread to investigate what kinds of viral, immunological, and epidemiological factors affect the predominance of SARS-CoV-2 novel variants. The results showed that the increase of the transmissibility of the novel variant substantially enhanced the predominance probability. In addition, the increasing trend of the infection spread, the large case number of the epidemic, and the ability of immune escape of the novel variant increased the predominance probability. A small number of cases and a decreasing trend of an entire epidemic, including not only the novel variant but also earlier strains, are especially important to reduce the chance of the predominance of the novel variant and delay the process. Good control of the COVID-19 epidemic could make the disease burden small and sequester the spread of the SARS-CoV-2 novel variants.

show abstract

Is large-scale vaccination sufficient for controlling the COVID-19 pandemic with uncertainties? A model-based study

Majumder,

Bairagi

2023

Nonlinear Dyn

View full text Add to dashboard Cite

A massive vaccination program against SARS-CoV-2 infection started at the beginning of 2021. Studies show that vaccinated people are subject to reinfection, and there is uncertainty in the rate of immunity loss, the force of infection, recovery rate, vaccine efficacy. Here we study a six-dimensional stochastic epidemic model with vaccine-induced immunity loss to demonstrate the effect of vaccination in controlling the Covid-19 epidemic. It is shown that the disease persists for a long time if the stochastic basic reproduction number (SBRN) is greater than unity. We have also proved a sufficient condition for disease eradication. Our analysis shows that the disease cannot persist if R ext 0V < 1. Noticeably, this condition may not hold if the infectivity increases or/and the vaccine-induced immunity loss increases. A case study was done using the Indian Covid-19 data to estimate the model parameters and the noise intensities. It is revealed that the mean extinction time increases with the increasing rate of immunity loss and force of infection. A nontrivial observation is that mass vaccination cannot eradicate the disease if the vaccine-induced immunity loss is higher than 23 %. The case is almost similar if the infectivity is also high. It implies that the infection will last long unless a long-lasting vaccine candidate appears or a low infectious variant replaces the highly contagious variant.

show abstract

Simulation of future COVID-19 epidemic by vaccination coverage scenarios in Japan

Cited by 15 publications

References 42 publications

Number of public health nurses and COVID-19 incidence rate by variant type: an ecological study of 47 prefectures in Japan

Number of public health nurses and COVID-19 incidence rate by variant type: an ecological study of 47 prefectures in Japan

Simulation study reveals factors that affect the predominance of SARS-CoV-2 novel variant

Is large-scale vaccination sufficient for controlling the COVID-19 pandemic with uncertainties? A model-based study

Contact Info

Product

Resources

About