Intranasal Vaccines In The Works For Plague, Tetanus, Diphtheria.(Brief Article)

2001 SEP 12 - (NewsRx.com & NewsRx.net) --

by N.R. Saltmarsh, staff medical writer - Better protection and ease of administration make intranasal delivery of tetanus, diphtheria, and plague vaccines promising, and studies in small animal models point to the potential for these new systems in humans.

H.O. Alpar and colleagues at the University of London described the benefits of intranasal delivery of established and newly developed vaccines in a report in Advanced Drug Delivery Reviews.

In the case of the current plague vaccine, it often fails to engender 100% protection against inhalational infection with Yersinia pestis, noted Alpar and coworkers a problem that could be overcome with an effective intranasal vaccine. Nonparenteral immunization might also counter logistical problems with plague immunization protocols, they added.

Consequently, researchers have developed a vaccine allowing intranasal and intratracheal administration of biodegradable microspheres composed of poly-L-(lactide) (PLLA) and Y. pestis subunit antigens F1 and V, which has been shown to protect experimental animals from inhalational and subcutaneous challenge with virulent Y. pestis bacilli in clinical trials, the researchers said.

In the case of tetanus and diphtheria, the benefit of nasal immunization is the potential for improved coverage, said Alpar and team. Maintaining protective immunity to diphtheria and tetanus currently requires booster injections, but if noninvasive vaccines could be readily distributed and possibly even self-administered, current coverage lapses could disappear.

To this end, researchers have extensively investigated the intranasal and inhalational routes of administration, delivering tetanus and diphtheria toxoids intranasally to ...