A Danish study released on Wednesday suggests face masks did not significantly protect wearers from the coronavirus compared to those without masks.

The study, published in the Annals of Internal Medicine, concluded that the “recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use.”