La nueva gripe A/H1N1 o gripe A/H1N1 (2009)
- Autores: José Antonio Cabezas Fernández del Campo
- Localización: Anales de la Real Academia Nacional de Farmacia, ISSN-e 1697-4298, ISSN 0034-0618, Nº. 4, 2009, págs. 947-963
- Idioma: español
- Enlaces
-
Resumen
The influenza A/H1N1 subtype viruses which were in circulation between 1930 and 1990 have undergone few changes. However, at the end of 1990´s an A/H1N1 virus emerged whose genome contains segments that are about one-third from �old� North American swine influenza, one-third from North American avian, and the remaining third evenly divided between swine and human origin. Until March 2009, transmission of this virus between humans has been little mentioned, probably because it has been very limited. However, from this date, when the description of a new modality of influenza was initially reported in Mexico and immediately after in United States of America, its propagation in many other countries on several continents has been very rapid, in spite of certain international measures taken for to prevent its diffusion. [On March 28, 2009, 13.398 confirmed cases in 48 countries, with 95 deaths, were reported; and on June, 3, there were more than 17.000 patients in 64 countries, 180 in Spain, near the pandemic alert (phase 6)]. Although this virus now shows low virulence (similar to that of the seasonal influenza virus) there is well founded fear about its possible evolution giving rise to more dangerous strains, either by mutation or by genetic reassortment with the influenza A/H1N1 virus responsible for seasonal influenza or with the influenza A/H5N1 virus typical of avian influenza. Fortunately, some of the measures that have been taken in recent years for the prevention or fight against the expected and feared pandemics that could arise from the abovementioned A/H5N1 avian virus have proved to be very useful now. Thus, the antiviral drugs oseltamivir (Tamiflu) and zanamivir (Relenza), which are inhibitors of the viral enzyme neuraminidase (= sialidase), are very effective agents against A/H1N1 virus of swine origin. However, the risk of appearance of resistant strains (as is the case for some A/HIN1 of seasonal influenza) advises cautious dispensation. Furthermore, vaccine production (probably with live attenuated virus), using similar techniques to those employed for conventional vaccines (although faster), is the modality recently recommended by the WHO, with no detriment to the manufacture of the seasonal vaccine. The use of more sophisticated procedures (cell culture, recombinant vaccines, etc.) has been discarded for the time being. On the other hand, the use of agents such as statins, which act as regulators in disorders occasionally produced by certain cytokines in some influenza cases, is generally considered as a possible complementary (or even replacement) therapy in possible pandemics, owing to their low cost and easy stocking. Likewise, it may be very useful in the future to have availab1e agents that act on viral components such as non structural NSl protein or on the viral matrix protein M2. Finally, the use of appropriate antibodies against certain viral components could also be promising. Accordingly, future plans for research in this field should be aim at finding agents able to stop some of the steps of the viral biological cycle. However, this must be done without detriment to the necessary preventive measures, and should endeavour not to create public alarm.
