Some Tolerance for Fur—Animal Studies in PLoS Medicine

P LoS Medicine is a suffi ciently new journal that we are often doing something for the fi rst time. This issue's " fi rst " is the publication of a research article that reports data exclusively from animals, more precisely from six cynomolgus macaques used to test the effi cacy of a new Lassa fever vaccine. There is no question that animal studies are an important part of medical research, but which ones, if any, belong in a medical journal? More to the point, which ones belong in PLoS Medicine? Although our journal's focus is on human studies, we have decided, on occasion, to publish animal studies that have important and proximal implications for clinical research, and maybe even practice. Lassa fever causes serious morbidity and mortality in West Africa. The virus's natural hosts are rodents, and as there is little chance for effective rodent control in the endemic areas, a vaccine is the most feasible way to gain control of the disease. Several research groups around the world have worked on vaccine development—and their efforts have been boosted by the classifi cation of Lassa virus as a Category A bioweapons agent—but to date no vaccine is available for either general or high-risk application in humans. Thomas Geisbert and colleagues have developed and now report tests of a recombinant vaccine based on a replication-competent vesicular stomatitis virus (DOI: 10.1371/ journal.pmed.0020183). One shot of this vaccine protected four out of four vaccinated monkeys against a lethal virus challenge, whereas the two control animals died, making the vaccine a serious candidate for future application in humans. Clearly many issues about this vaccine still need to be resolved, such as vector safety, duration of protection, and breadth of protection (there are at least four distinct Lassa virus strains). Nevertheless, we accepted this paper because we and our advisers felt that the research was at a stage where clinical questions, such as patient safety and design of early human trials, should inform any additional studies in animals. The proper place for such a study is, we believe, a clinical journal. There are several other types of animal studies we consider appropriate for publication in PLoS Medicine. These include studies that explore off-label uses of approved medical interventions in validated animal disease models, again based on the studies' direct relevance to potential treatment of human patients. More often, we would publish human studies that …