As authors of the Cochrane review that questions the stockpiling of the antiviral drugs Tamiflu (oseltamivir) and Relenza (zanamivir) against influenza pandemics, we wish to clarify aspects of your report on criticisms of the review (see Nature 508, 439–440; 2014).

We agree that the randomized clinical trials of Tamiflu were “not designed to test for the severe outcomes”. But far from undermining our review, this is actually one of our important findings. This is because, for years, governmental bodies justified stockpiling Tamiflu (see go.nature.com/ucyjwb and go.nature.com/oi9zbg) on the basis of a short analysis of ten pooled randomized trials (L. Kaiser et al. Arch. Intern. Med. 163, 1667–1672; 2003).That study was authored by researchers at Roche, the manufacturer of Tamiflu, and concludes that the drug significantly reduces complications and hospitalizations in healthy and at-risk adults.

Our Cochrane review, by contrast, independently evaluated data from the full, previously confidential, trial-evidence base — something that officials should have done themselves. Critics of our research miss the point about what our findings say about government accountability.

You incorrectly refer to the randomized trials as “small”, which would call the generalizability of the conclusions into question. In fact, trial M76001 had more than 1,400 participants, and the two pivotal studies (WV15670 and WV15671) each had more than 600 participants. You also omit to mention that the trials enrolled at-risk as well as healthy subjects.

Your report cites an observational study in which neuraminidase inhibitors (the drug class to which Tamiflu and Relenza belong) reduced mortality in hospitalized patients during the H1N1 influenza outbreak in 2009–10, apparently aligning with criticisms of our review for not including such observational studies. However, you omitted to mention the limitations of that study — or that it was funded by Roche.

We stand by our conclusion that government decisions to stockpile Tamiflu should be backed by high-quality evidence of safety and effectiveness.