Aerosol Vaccines ready for clinical trials

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Here is the link to the journal article:

http://documents.scribd.com/docs/22yreuykq5s5gu9j17t2.pdf

Researchers have demonstrated that aerosol-delivered vaccines based on

poxviruses are safe and effective in a trial on monkeys.

http://www.scidev.net/news/index.cfm?fuseaction=printarticle & itemid=4246 & languag\

e=1

Aerosol vaccines have been hailed for their potential in the

developing world, where lack of trained personnel, problems with

hygienic supplies and social acceptance issues are barriers to

conventional, injected vaccines.

The study authors say the method could be particularly useful in

vaccinating against diseases that enter the body through mucous

membranes, such as genital herpes, human papilloma virus, hepatitis B

and HIV.

Their study, published in the Proceedings of the National Academy of

Sciences last week (11 February), illustrates that the aerosol method

works as a way of delivering vaccines for such diseases.

The researchers tested for safety and immune response using two

vaccines, one based on an experimental HIV vaccine and the other a

human papilloma virus (HPV) vaccine.

Rhesus macaque monkeys were administered the vaccines in an aerosol

preparation, delivered through a nebulizer — a device that turns

liquid medication into vapour — and face mask.

The scientists found that the vaccines were safe and absorbed mainly

into the respiratory tract and lungs, rather than the brain or eyes

where they could cause damage. They also elicited a " robust and long

lasting " immune response.

Jean-Pierre Kraehenbuhl, senior scientist at the Eurovacc Foundation

at the Swiss Institute for Experimental Cancer Research (ISREC) and

coordinator of the study, says the benefit of aerosol vaccines is that

they provide immunity both in the mucosal tissue that pathogens invade

and the rest of the body. Most injected vaccines don't provide mucosal

immunity.

Kraehenbuhl told SciDev.Net that the next step for the research is

phase I clinical trials in humans, due to start this year. These will

analyse how the vaccine is distributed in human lungs.

There is already an ongoing clinical trial for a measles aerosol

vaccine, part of a WHO-led project.

Hall, professor of epidemiology at the UK-based London School

of Hygiene and Tropical Medicine, says the paper demonstrates that the

aerosol route can be applied to other vaccines besides those tested

for measles.

" Most interestingly this could result in some immunity at other

mucosal sites " , he says, but adds that it is unclear at this stage

whether the immunity would be protective.