The needle-free vaccination against travellers’ diarrhoea is expected to be on the market by 2013.

Its developer, Austrian pharmaceutical manufacturer, Intercell has signed a major deal with one of the world’s largest vaccine producers, UK firm GlaxoSmithKline (GSK), to market the TD vaccine and use the innovative technology to potentially deliver other vaccines and drugs.

The new vaccine is the first specifically for TD. Currently the best option for travellers is the oral cholera vaccine, Dukoral, which also provides cross-protection of around 67% against the most common cause of TD, enterotoxigenic E Coli (ETEC).

It’s just a light scrape of the skin

Intercell’s new patch lightly scrapes the outer surface of the skin with an emery board-like material. The patch then releases the vaccine into the body over several hours.

The patch requires two applications: one just before travel and another within three weeks. The trials will also test how long the vaccine’s protection lasts.

Trials underway in high-risk regions

The company has two late-stage clinical trials underway, vaccinating 800 European travellers to India, and 1800 heading to Mexico and Guatemala.

The main objective of the trial is prevention of all moderate-to-severe cases of diarrhoea in which LT, LT/ST or ST toxins (ETEC) are detected.

Successful mid-stage clinical tests in 170 travellers published last year showed a reduction by three quarters of moderate to severe diarrhoea. If the late-stage test results are positive, Intercell plans to file for regulatory approval.

Needle-free vaccines appeal to everyone

Skin patch vaccines appeal to travellers and travel health professionals alike. Apart from reducing perceived or real pain, some studies suggest patches that apply vaccines just under the skin can strengthen the body’s immune response, reducing the amount of vaccine required or even enhancing safety.

“The idea of using patch technology for the delivery of vaccines has been well received by travel medicine providers, as well as by needle-phobic travellers,” said Travelvax Australia’s medical director, Dr Eddy Bajrovic.

“Patch technology could offer benefits like easy administration and direct delivery of the antigen and adjuvant to the immune system through a natural defense pathway, making vaccination more efficient.”

Holidays and business trips can be ruined by TD. Studies show that each year between 20%-60% of travellers will get mild to severe TD during an overseas trip, with young adults most susceptible.

“In high-risk regions such as Asia, Africa, Central and South America, and the Middle East, TD rates can be up to 90% for stays of two weeks,” Dr Bajrovic said.

“But, the vaccine will not offer complete protection and travellers must continue to follow the golden rules when it comes to eating, drinking and personal hygiene.”

More patch vaccines are planned

So confident is GSK that the vaccine will be a winner, earlier this month it paid €34m ($50m) for a share of the profits from sales and invested a further €84m for five per cent of equity in Intercell. The deal with GSK also includes joint development of a future generation of pandemic flu vaccines.

Other companies are at early stages of developing alternatives to syringes for preventive vaccines using undetectable microneedles, small pieces of gold inserted via pressure, as well as using heat and radio frequencies.

Intercell’s patch appears to be the most advanced. The company already has a Japanese encephalitis patch vaccine (see below) on the market and is developing others for a range of infectious diseases, some in partnership with other large pharmaceutical groups.

Children may be ‘patched up’ for Japanese encephalitis

Intercell is also conducting a multi-national trial involving 100 children to investigate the safety of its Japanese encephalitis (JE) patch vaccine, which is currently only licensed for use in adults.

As JE is a seasonal risk in rice-growing rural areas, vaccination against the mosquito-borne disease is generally not recommended for leisure travellers visiting endemic countries in Asia.

The risk generally is higher for those travelling extensively through, or spending extended periods in, rice growing areas of endemic countries, especially during the rainy season.

Countries which have periodic epidemics of JE include Vietnam, Cambodia, Myanmar, India, Nepal, and Malaysia.

* For more information, contact Travelvax Australia. We have 32 clinics across the country and offer free, no-obligation travel health advice on 1300 360 164. To unsubscribe please email admin@travelvax.com.au