Australian participation in the two upcoming international Group One races at Sha Tin is under a cloud due to a shortage of equine influenza vaccine.

There are 12 nominations from Australia for the Audemars Piguet QE II Cup on April 28 and the Champions Mile on May 5, although confirmation of such runners usually would not take place until after some major Group One meetings under way at the Sydney autumn racing carnival.

It appears the only potential runners at Sha Tin from Australian stables would be Chris Waller-trained Shoot Out in the Champions Mile and Mike Moroney-trained Glass Harmonium for the QE II Cup.

An outbreak of the highly contagious equine influenza shut down racing for several months in parts of Australia's eastern coast in late 2007, and there is now a shortage in the country of the vaccine, which chemical company Pfizer produces.

"The current batch expired on March 9, but to meet the travel restrictions for our races any horse needed to be vaccinated by March 7," said executive director of racing Bill Nader yesterday. "Any horse, which has been vaccinated with a view to coming to Hong Kong, does require a booster shot before travel, but I am assured by both of the major airfreight companies the new batch of vaccine should arrive before the booster is required."

The entries for the Group One double include big names from Japan such as Eishin Flash and Fenomeno, the quinella in the recent Group One Tenno Sho (Autumn) and some reports are suggesting the Japanese are keen to defend the QE II Cup won by Rulership last year.

The lists of entries also include several horses from the Mike De Kock stable and even the US star, Animal Kingdom, all of them engaged in Dubai and Nader said no firm decisions were expected until early April.

"We usually get a few horses, which come to the Champions Mile and QE II Cup through the Dubai World Cup meeting, but obviously none of their connections will commit to Hong Kong until they've had their race in Dubai," he said.