To avoid losing valuable knowledge and to accelerate decision-making during the current Zika public-health emergency, the World Health Organization (WHO) and international partners are renewing efforts to promote rapid sharing of the latest research data (see go.nature.com/qtf5x4). Data sharing is important for all medical research, and particularly during outbreaks of such new and unstudied diseases (see, for example, N. L. Yozwiak et al. Nature 518, 477–479; 2015).

The International Committee of Medical Journal Editors has ruled that, in a WHO public-health emergency, dissemination of raw information critical to public health will not prejudice later publication by researchers in the same journal. This is important, because it prioritizes open access and real-time disclosure over competition between researchers and companies rushing to publish successful trial results.

The Bulletin of the World Health Organization has also made publication of papers and raw data on Zika virus open-access and immediate (see go.nature.com/djfyzf). So far, more than 30 funding and research agencies and medical journals are supporting the initiative.

Failure to disclose medical research data promptly and publicly can give rise to misinformation, leading to treatments that are dangerous or ineffective, or to delays in effective treatments. It also wastes precious public-health resources.