Low selenium status is associated with increased risk of thyroid disease. Increased selenium intake may reduce the risk in areas of low selenium intake that exist not only in China but also in many other parts of the world.
Background
Multiple candidates of COVID-19 vaccines have entered Phase III clinical trials in the United States (US). There is growing optimism that social distancing restrictions and face mask requirements could be eased with widespread vaccine adoption soon.
Methods
We developed a dynamic compartmental model of COVID-19 transmission for the four most severely affected states (New York, Texas, Florida, and California). We evaluated the vaccine effectiveness and coverage required to suppress the COVID-19 epidemic in scenarios when social contact was to return to pre-pandemic levels and face mask use was reduced. Daily and cumulative COVID-19 infection and death cases from 26th January to 15th September 2020 were obtained from the Johns Hopkins University Coronavirus resource center and used for model calibration.
Results
Without a vaccine (scenario 1), the spread of COVID-19 could be suppressed in these states by maintaining strict social distancing measures and face mask use levels. But relaxing social distancing restrictions to the pre-pandemic level without changing the current face mask use would lead to a new COVID-19 outbreak, resulting in 0.8-4 million infections and 15,000-240,000 deaths across these four states over the next 12 months. Under this circumstance, introducing a vaccine (scenario 2) would partially offset this negative impact even if the vaccine effectiveness and coverage are relatively low. However, if face mask use is reduced by 50% (scenario 3), a vaccine that is only 50% effective (weak vaccine) would require coverage of 55-94% to suppress the epidemic in these states. A vaccine that is 80% effective (moderate vaccine) would only require 32-57% coverage to suppress the epidemic. In contrast, if face mask usage stops completely (scenario 4), a weak vaccine would not suppress the epidemic, and further major outbreaks would occur. A moderate vaccine with coverage of 48-78% or a strong vaccine (100% effective) with coverage of 33-58% would be required to suppress the epidemic. Delaying vaccination rollout for 1-2 months would not substantially alter the epidemic trend if the current non-pharmaceutical interventions are maintained.
Conclusions
The degree to which the US population can relax social distancing restrictions and face mask use will depend greatly on the effectiveness and coverage of a potential COVID-19 vaccine if future epidemics are to be prevented. Only a highly effective vaccine will enable the US population to return to life as it was before the pandemic.
Background Coinciding with the release of the first Chinese domestic human papillomavirus (HPV) vaccine Cecolin in 2019, and the substantial advancements in cervical cancer screening technology, we aimed to evaluate the costeffectiveness of the combined strategies of cervical cancer screening programmes and universal vaccination of girls (aged 9-14 years) with Cecolin in China.Methods We did a cost-effectiveness analysis in China, in which we developed a Markov model of cervical cancer to evaluate the incremental cost-effectiveness ratios of 61 intervention strategies, including a combination of various screening methods at different frequencies with and without vaccination, and also vaccination alone, from a healthcare system perspective. We did univariate and probabilistic sensitivity analyses to assess the robustness of the model's findings.Findings Compared with no intervention, various combined screening and vaccination strategies would incur an additional cost of US$6 157 000-22 146 000 and result in 691-970 quality-adjusted life-years (QALYs) gained in a designated cohort of 100 000 girls aged 9-14 years over a lifetime. With a willingness-to-pay threshold of three times the Chinese per-capita gross domestic product (GDP), careHPV screening (a rapid HPV test) once every 5 years with vaccination would be the most cost-effective strategy with an incremental cost-effectiveness ratio of $21 799 per QALY compared with the lower-cost non-dominated strategy on the cost-effectiveness frontier, and the probability of it being cost-effective (44%) outperformed other strategies. Strategies that combined screening and vaccination would be more cost-effective than screening alone strategies when the vaccination cost was less than $50 for two doses, even with a lower willingness-to-pay of one times the per-capita GDP.Interpretation careHPV screening once every 5 years with vaccination is the most cost-effective strategy for cervical cancer prevention in China. A reduction in the domestic HPV vaccine price is necessary to ascertain a good economic return for the future vaccination programme. The findings provide important evidence that informs health policies for cervical cancer prevention in China.
Hubei province in China has completed cycle of quarantine-resumption in 23rd Janauary and 8th April 2020, providing a unique opportunity as for now to assess its intervention impact and the pattern of SARS-COV-2 transmission during the quarantine period. In this study, we evaluate the impact of the metropolitan-wide quarantine on the trend and transmission route of the COVID-19 epidemic in Hubei, China. The intervention reduces more than 70% of new infections in both households and the public space, as well as the deaths caused by COVID-19 pneumonia. Household transmission is the dominant route of disease spread regardless of quarantine. This will provide important evidence and scientific insights to other worldwide countries that are currently under quarantine.
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