Assessing vaccination priorities for different ages and age-specific vaccination strategies of COVID-19 using an SEIR modelling approach.

In the past year, the global epidemic situation is still not optimistic, showing a trend of continuous expansion. With the research and application of vaccines, there is an urgent need to develop some optimal vaccination strategies. How to make a reasonable vaccination strategy to determine the priority of vaccination under the limited vaccine resources to control the epidemic and reduce human casualties? We build a dynamic model with vaccination which is extended the classical SEIR model. By fitting the epidemic data of three countries-China, Brazil, Indonesia, we have evaluated age-specific vaccination strategy for the number of infections and deaths. Furthermore, we have evaluated the impact of age-specific vaccination strategies on the number of the basic reproduction number. At last, we also have evaluated the different age structure of the vaccination priority. It shows that giving priority to vaccination of young people can control the number of infections, while giving priority to vaccination of the elderly can greatly reduce the number of deaths in most cases. Furthermore, we have found that young people should be mainly vaccinated to reduce the number of infections. When the emphasis is on reducing the number of deaths, it is important to focus vaccination on the elderly. Simulations suggest that appropriate age-specific vaccination strategies can effectively control the epidemic, both in terms of the number of infections and deaths.

Caracterización epidemiológica del trauma ocular a globo abierto / Epidemiological characterization of open globe ocular trauma

RESUMEN Objetivo: Determinar las características clínico-epidemiológicas del trauma ocular a globo abierto. Métodos: Se realizó un estudio descriptivo, observacional y transversal en pacientes con trauma ocular a globo abierto y afectación del segmento posterior en pacientes hospitalizados en el Servicio de Vítreo-Retina del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" entre julio del año 2017 y julio de 2018. Resultados: El 68,18 por ciento de los pacientes fue menor de 50 años y el 88,64 por ciento fueron hombres. El trauma más común fue el penetrante (91,11 por ciento); el 68,89 por ciento de las lesiones ocurrió en zona 1, con predominio de las heridas menor o igual a 4 mm (75,56 por ciento). La circunstancia más común del trauma fue la laboral (50 por ciento). El mecanismo de producción predominante fue el martilleo sobre metal (71,11 por ciento); el 65,91 por ciento de los traumas ocurrieron en zona urbana; el 96,46 por ciento no usaba protección; el 57,77 por ciento tenía una agudeza visual inicial de cuenta dedo o mejor, y la presencia de cuerpo extraño intraocular ocupó el 77,78 por ciento. Conclusiones: En el trauma ocular a globo abierto predominan la edad por debajo de 50 años, el sexo masculino y los traumas penetrantes. La mayor parte se presenta de forma unilateral, durante las actividades laborales y sin protección ocular. Más de la mitad de los pacientes presentan agudeza visual inicial de cuenta dedos o mejor. Los signos oculares asociados más frecuentes son el cuerpo extraño intraocular y la catarata traumática(AU)

ABSTRACT Objective: Determine the clinical-epidemiological characteristics of open globe ocular trauma. Methods: A cross-sectional observational descriptive study was conducted of open globe ocular trauma and posterior segment damage in patients admitted to the Vitreous-Retina Service of Ramón Pando Ferrer Cuban Institute of Ophthalmology from July 2017 to July 2018. Results: Of the patients studied, 68.18 percent were under 50 years of age and 88.64 percent were men. Penetrating trauma was the most common type (91.11 percent); 68.89 percent of the lesions were found in zone 1, with a predominance of injuries smaller than or equal to 4 mm (75.56 percent). Most traumas occurred while at work (50 percent). The prevailing occupational activity being performed at the moment of the trauma was hammering on metal (71.11 percent); 65.91 percent of the traumas occurred in urban areas; 96.46 percent of the patients were not wearing the required protection equipment; 57.77 percent had an initial visual acuity of count fingers or better; and participation of foreign bodies accounted for 77.78 percent. Conclusions: In open globe ocular trauma a predominance is found of age under 50 years, male sex and penetrating traumas. Most are unilateral and occur while working without the required ocular protection. In more than half of the patients initial visual acuity is finger counting or better. The most common associated ocular signs are intraocular foreign body and traumatic cataract(AU)