All Nature’s pandemic flu coverage is collected on our news special page. These regular updates on The Great Beyond round up the latest from other news sources around the globe.

A sweeping analysis of pandemic H1N1 (swine) flu suggests that –- at least as far as our immune systems are concerned — the virus bears some similarity to the dreaded 1918 pandemic virus that claimed upwards of 50 million lives.

The study, published online by Nature today, evaluates the virus in mice, ferrets, macaques, pigs, and human cell cultures. Many of the results are by now familiar: the virus is susceptible to oseltamivir (better known as Tamiflu) and zanamivir (marketed as Relenza), and causes a nasty disease in ferrets (see ‘Swine flu reaches into the lungs and gut’). The virus does not cause much disease in pigs, although it does replicate well there (see ‘Patchy pig monitoring may hide flu threat’ for more on this).

But one interesting new finding addresses the long-standing question of why some people aged 60 years and older appear to be better able to fend off the virus than younger patients. Previous work from the Centers for Disease Control suggested that exposure to previous flu strains may have conferred some residual immunity (see ‘Old seasonal flu antibodies target swine flu virus’). Now, Yoshihiro Kawaoka of Kobe University at the University of Wisconsin-Madison, and his colleagues have narrowed the time frame during which this exposure may have taken place. Specifically, patients born before 1920 are more likely to produce antibodies capable of neutralizing the new H1N1 swine flu, suggesting that exposure to the 1918 flu or a close relative may be the reason.

“Collectively, our findings are a reminder that [swine-origin H1N1 influenza viruses] have not yet garnered a place in history, but may still do so, as the pandemic caused by these viruses has the potential to produce a significant impact on human health and the global economy,” the authors conclude.