Expert shows how nasal vaccines for bioagents could be created

Dennis Metzger presented research at the Society for General Microbiology’s Spring Conference that describes how nasal vaccines that protect effectively against flu, pneumonia and bioterrorism agents like plague could be created.

During the conference, which was held in Harrogate, United Kingdom, Metzger described that including a natural immune chemical with standard vaccines might be able to boost the protective effect when delivered through the nose, Science Daily reports.

Currently, there are few approved vaccines that provide optimal protection against viral and bacterial pathogens due to the low immune response at mucosal surfaces like the nasal passages.

Metzger discussed research that demonstrated the combination of the immune chemical interleukin-12 and standard vaccines for respiratory pathogens and delivering them nasally to mice that induced high levels of protection.

This method was used against several pathogens, including the Category A biothreat Yersina Pestis, which causes the plague.

“Infectious agents still account for around 25 percent of deaths worldwide and the major killers are acute respiratory infections," Metzger said, Science Daily reports. "However, it is difficult to induce immunity at the site of entry and so standard vaccines are only partially protective. Intranasal vaccination gets around this problem by inducing immunity in the pulmonary passage. This prevents initial infection as well as systemic complications. We now have evidence that this method could work for a wide range of vaccines when IL-12 is included in formulation.”

Metzger noted multiple advantages that nasal vaccines might have over vaccines that must be injected.

"Vaccination via a nasal spray is a non-invasive procedure that is easier than administering vaccines by injection," Metzger said, according to Science Daily. "In addition our results have shown that antibodies induced by intranasal vaccination are effective not only in preventing infection but can also protect the pulmonary tract in a therapeutic manner after pathogen exposure. In the case of a bioterrorism threat or an influenza pandemic, this is significant."

The next step in the process will be to perform clinical trials to determine if including IL-12 with intranasal vaccines will be effective in the human population.