BioWorld International Correspondent

LONDON - Quarantine measures protecting Dolly the sheep and her cloned peers have been stepped up in the face of the outbreak of foot and mouth disease that is raging across the UK. More than 70 cases of the highly virulent disease have been diagnosed in all areas of the country.

The Roslin Institute near Edinburgh, where Dolly lives, is closed to visitors, and Dolly has been put in her own housing.

PPL Therapeutics plc, which developed Dolly in collaboration with Roslin, also has stepped up the quarantine measures at its farms in Scotland, where it houses transgenic flocks used for the production of human proteins. Production flocks for PPL's lead product, alpha-1-antitrypsin, which is about to enter Phase III clinical trials with Bayer, are based at the farms, although the company has other production stock in New Zealand. It also has semen stocks of all important lines. It would take time, and delay development, but flocks could be regenerated if necessary.

April D'Arcy, PPL's spokeswoman, told BioWorld International there would be no exemptions to the policy of slaughtering and incinerating infected flocks. "That's why it is important that quarantine measures are kept up at all times. Our farms are protected to avoid contact with other animals, and we have stepped up protection measures."

PPL has maintained one quarantine farm in Scotland for the last nine years, during which no animals have entered the farm, other than the founder sheep, which were flown in from New Zealand. The farm is surrounded by arable land, protected by deer fencing, and there are no adjacent livestock farms. Access to this, and PPL's other farm, is controlled and four vets continuously monitor the health of the flocks. In response to the foot and mouth outbreak, quarantine and disinfection procedures have been stepped up, and the movement of staff is being tightly controlled.

In a statement PPL said, "The company believes that an outbreak on either of its UK farms is unlikely, but if it occurs PPL believes that, because of the measures [taken] the impact on the company would be limited."