Browsing by Author "Simpson CR"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- ItemCOVID-19 vaccine strategies for Aotearoa New Zealand: a mathematical modelling study(Elsevier Ltd, 2021-10) Nguyen T; Adnan M; Nguyen BP; de Ligt J; Geoghegan JL; Dean R; Jefferies S; Baker MG; Seah WKG; Sporle AA; French NP; Murdoch DR; Welch D; Simpson CRBackground: COVID-19 elimination measures, including border closures have been applied in New Zealand. We have modelled the potential effect of vaccination programmes for opening borders. Methods: We used a deterministic age-stratified Susceptible, Exposed, Infectious, Recovered (SEIR) model. We minimised spread by varying the age-stratified vaccine allocation to find the minimum herd immunity requirements (the effective reproduction number Reff<1 with closed borders) under various vaccine effectiveness (VE) scenarios and R0 values. We ran two-year open-border simulations for two vaccine strategies: minimising Reff and targeting high-risk groups. Findings: Targeting of high-risk groups will result in lower hospitalisations and deaths in most scenarios. Reaching the herd immunity threshold (HIT) with a vaccine of 90% VE against disease and 80% VE against infection requires at least 86•5% total population uptake for R0=4•5 (with high vaccination coverage for 30-49-year-olds) and 98•1% uptake for R0=6. In a two-year open-border scenario with 10 overseas cases daily and 90% total population vaccine uptake (including 0-15 year olds) with the same vaccine, the strategy of targeting high-risk groups is close to achieving HIT, with an estimated 11,400 total hospitalisations (peak 324 active and 36 new daily cases in hospitals), and 1,030 total deaths. Interpretation: Targeting high-risk groups for vaccination will result in fewer hospitalisations and deaths with open borders compared to targeting reduced transmission. With a highly effective vaccine and a high total uptake, opening borders will result in increasing cases, hospitalisations, and deaths. Other public health and social measures will still be required as part of an effective pandemic response. Funding: This project was funded by the Health Research Council [20/1018]. Research in context.
- ItemValidation and Cultural Adaptation of the Motors of COVID-19 Vaccination Acceptance Scale (MoVac-COVID19S) in German(Hogrefe, 2023-12-01) Adu P; Popoola T; Roemer A; Collings S; Aspin C; Medvedev ON; Simpson CRBackground: Context-specific standardized psychometric instruments are essential for ensuring valid and reliable assessment of health outcomes across diverse populations to aid the advancement of research and health-related interventions. However, instruments measuring attitudes toward vaccinations are lacking in the extant literature. Therefore, we performed a cross-cultural adaptation of the Motors of COVID-19 Vaccination Acceptance Scale (MoVac-COVID19S) in Germany. Method: During the months of June and July 2022, 475 individuals aged 18 years and older from the general population of Germany participated in an online cross-sectional survey. Participants responded to five demographic questions, a measure of COVID-19 vaccine uptake willingness, and the MoVac-COVID19S. Confirmatory Factor Analysis (CFA) fit indices were used to evaluate the factor structures of the MoVac-COVID19S. Results: The CFA revealed that all examined factor structures of both the 9-item and 12-item versions of the MoVac-COVID19S were acceptable among the sample. Overall, CFI, GFI, and TLI values were higher than 0.95; RMSEA and SRMR values were all less than 0.08 for all the estimated models. The one-factor model of the 9-item version of the MoVac-COVID19S exhibited best fits indices compared to the one-factor and four-factor structures of the 12-item version of the scale. The bifactor model revealed that the general factor explained a higher percentage of the Explained Common Variance (ECV; ranging from 55% to 94%) in the majority of the items, compared to the specific factors. The scale was found to demonstrate convergent validity with related measures. Conclusion: The German version of the MoVac-COVID19S should be considered a unidi-mensional rather than a multidimensional measure. Although the 9-item version of the scale performed better among the sample compared to the 12-item version, the overall scores of both versions were found to be valid and reliable measures of attitudes toward COVID-19 vaccinations. The MoVac-COVID19S has the potential to be adapted for assessing attitudes toward any future vaccination programs. Limitations: While our study sampled only the general German population, the criticisms of CFA warrant further research using advanced methods, such as the Rasch model, and subgroups.