Scientists have demonstrated for the first time that a single-dose, needleless Ebola vaccine given to primates through their noses and lungs protected them against infection for at least 21 weeks. A vaccine that doesn't require an injection could help prevent passing along infections through unintentional pricks. They report the results of their study on macaques in the ACS journal Molecular Pharmaceutics.
Maria A. Croyle and colleagues note that in the current Ebola outbreak, which is expected to involve thousands more infections and deaths before it's over, an effective vaccine could help turn the tide. Even better, taking the needle out of the inoculation process could also help prevent the accidental transmission of Ebola, as well as other diseases, such as HIV, that might otherwise spread from unintentional needle pricks and unsafe handling of medical wastes. Other vaccines are currently under development to fight the virus, but they require an injection. Croyle's team tested an adenovirus-based Ebola vaccine using a respiratory delivery route.
The researchers gave a novel formulation of an Ebola vaccine to several macaques then exposed them to the virus more than four months later. All three of the animals that received the vaccine through the nose and via a catheter into their airways did not fall ill. However, since special equipment and training are required for the current respiratory delivery method, the scientists conclude that further work is needed if this formula, or an under-the-tongue version, is to be used eventually in large-scale immunization campaigns.
The authors acknowledge funding from the National Institutes of Health.
Study: A Single Dose Respiratory Recombinant Adenovirus-Based Vaccine Provides Long-Term Protection for Non-Human Primates from Lethal Ebola Infection, Jin Huk Choi, Kristina Jonsson-Schmunk, Xiangguo Qiu, Devon J Shedlock, Jim Strong, Jason X Xu, Kelly L Michie, Jonathan Audet, Lisa Fernando , Mark j Myers, David B. Weiner, Irnela Bajrovic, Lilian Q Tran, Gary Wong, Alexander Bello, Gary P Kobinger, Stephen C Schafer, and Maria A. Croyle, Molecular Pharmaceutics, DOI: 10.1021/mp500646d, published 1 November 2014.