Clinical trial shows N95 respirator and medical mask provide similar protection. The Respiratory Protection Effectiveness Clinical Trial (ResPECT) found no significant difference between the N95 respirator and the medical mask in preventing influenza infection among outpatient health care personnel in close contact with patients suspected of respiratory illness. This four-year study published in the September 3 JAMA involved 2,862 participants and was conducted during the 12-week period of peak respiratory illness at 137 outpatient study sites. Results showed that the incidence of laboratory-confirmed influenza was 8.2% among health care workers using the N95 respirator versus 7.2% among those using the medical mask. This study confirms that medical masks do what they are designed to do: protect against infections such as influenza that are spread via droplet transmission.