Vacunación frente a rotavirus en niños prematuros: una cuestión de tiempo / Rotavirus vaccine in preterm infants: a matter of time

La infección por rotavirus continúa siendo un problema relevante de salud pública en los países desarrollados, y los niños prematuros constituyen la población más vulnerable tanto en términos de riesgo de infección como por la gravedad de la misma. En la actualidad existen dos vacunas frente a rotavirus disponibles en España: la vacuna pentavalente bovina-humana reordenada (RotaTeq®, MSD) y la monovalente humana atenuada (Rotarix®, Glaxo-SmithKline Biologicals). Los datos de los ensayos clínicos y estudios observacionales indican que la vacunación anti-rotavirus en niños prematuros es bien tolerada y segura, con un perfil similar en este sentido al observado en niños nacidos a término. Por otra parte, los resultados de los estudios clínicos y observacionales también apoyan una eficacia similar a la comunicada en niños a término. Más aún, al tratarse de un grupo de mayor riesgo de infecciones, es posible teóricamente que el beneficio obtenido sea incluso mayor que en niños a término. La transmisión horizontal del virus vacunal, aun siendo posible, no ha sido documentada en ensayos clínicos y los estudios observacionales existentes hasta ahora sugieren un riesgo bajo. En consonancia con diversas recomendaciones nacionales e internacionales, consideramos que esta población, siempre que su condición clínica lo permita, debe recibir la vacunación frente a rotavirus sin retrasos, incluyendo su vacunación mientras estén hospitalizados, si así fuese necesario

Rotavirus infection continues to be a relevant public health problem in developed countries and premature children constitute a more vulnerable population both in terms of risk and severity of infection. Currently, there are two available vaccines against rotavirus in Spain: the pentavalent bovine-human reasortant vaccine (RotaTeq®, MSD) and the attenuated human monovalent vaccine (Rotarix®, GlaxoSmithKline Biologicals). Results from clinical trials and from observational studies indicate that anti-rotavirus vaccination in preterm infants is well tolerated and safe, with a similar profile in this regard to that reported in full-term infants. On the other hand, the results of clinical trials and observational studies also support efficacy similar to that reported in children at term. Moreover, as it is a group with a higher risk of infections, it is theoretically possible that the benefit obtained is even greater than in full-term children. The virus transmission to unvaccinated contacts, although possible, has not been documented in clinical studies and the studies published to date so far suggest a low risk in this regard. Consistently with various national and international recommendations, these authors therefore consider that this population, whenever its clinical condition permits, should receive vaccination against rotavirus without delays, including vaccination while hospitalized, if necessary

Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation.

Pluto and Eris are icy dwarf planets with nearly identical sizes, comparable densities and similar surface compositions as revealed by spectroscopic studies. Pluto possesses an atmosphere whereas Eris does not; the difference probably arises from their differing distances from the Sun, and explains their different albedos. Makemake is another icy dwarf planet with a spectrum similar to Eris and Pluto, and is currently at a distance to the Sun intermediate between the two. Although Makemake's size (1,420 ± 60 km) and albedo are roughly known, there has been no constraint on its density and there were expectations that it could have a Pluto-like atmosphere. Here we report the results from a stellar occultation by Makemake on 2011 April 23. Our preferred solution that fits the occultation chords corresponds to a body with projected axes of 1,430 ± 9 km (1σ) and 1,502 ± 45 km, implying a V-band geometric albedo p(V) = 0.77 ± 0.03. This albedo is larger than that of Pluto, but smaller than that of Eris. The disappearances and reappearances of the star were abrupt, showing that Makemake has no global Pluto-like atmosphere at an upper limit of 4-12 nanobar (1σ) for the surface pressure, although a localized atmosphere is possible. A density of 1.7 ± 0.3 g cm(-3) is inferred from the data.

A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation.

The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1 AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 UT. The event is consistent with a spherical shape for Eris, with radius 1,163 ± 6 kilometres, density 2.52 ± 0.05 grams per cm(3) and a high visible geometric albedo, Pv = 0.96(+0.09)(-0.04). No nitrogen, argon or methane atmospheres are detected with surface pressure larger than ∼1 nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun.