Given these important inflammatory processes, it is important to attempt patient prophylaxis. Several antiviral agents were tested both in vitro and/or in vivo and presented results implicating that the early use of such agents suppress the inflammation apart from being a therapy [43] [44] [45] [46] [47] [48] [49] Antibiotics especially macrolides, which are well known for their anti-inflammatory and immunomodulatory properties were also tested. Clarithromycin inhibits the middle to late stage of the influenza virus replication cycle, resulting in inhibition of progeny virus production from the infected cells. Macrolides could mediate this effect by inhibiting intracellular hemagglutinin HA0 proteolysis. The inhibitory effect on influenza virus replication of macrolides has been known since the 80s [50] [51] [52] [53] [54] . N-acetylcysteine (NAC) is a thiol-containing compound which non-enzymatically interacts and detoxifies reactive electrophiles and free radicals. NAC has already been shown to effectively protect human bronchial fibroblasts against the toxic effects of tobacco smoke condensates and the isolated perfused lung against the glutathione (GSH)-depleting effect of tobacco smoke. NAC has also been demonstrated to reduce the reactive oxygen intermediate hydrogen peroxide (H 2 O 2 ) and to confer protection from the toxic effects of H 2 O 2 . In vivo studies, however, have demonstrated that orally administered NAC has very low bioavailability due to its rapid metabolism mainly to GSH but also other metabolites. Thus, even though NAC is very effective in protecting cells of different origins from the toxicity of reactive components in tobacco smoke and reactive oxygen species, a direct scavenging effect by NAC in vivo, does not seem likely. This holds especially true for oral administration. A more relevant mechanism in vivo for any protective effect of NAC may be attributable to its activity as a precursor of GSH, thereby facilitating its biosynthesis. GSH will then serve as the protective agent and detoxify reactive species both enzymatically and non-enzymatically [55, 56] . Finally, the efficacy of vaccination for H1N1 has been documented by assessing antibody formation in the vaccinated elderly subjects from the 2009 pandemic in contrast to the younger ones who were not vaccinated. Nonetheless, antibodies from older subjects previous encounter with pandemic influenza A strains may be a confounding factor [57] .