Infographic (high resolution) (IMAGE) McMaster University Caption Study finds vaccines delivered directly into the lungs via inhalation stimulate a stronger immune response than those delivered by nasal spray. Credit McMaster University Usage Restrictions None. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.