Eight rescued common seal pups will be swimming to freedom on Saturday after being given an in-built defence against a deadly virus by experts in North Yorkshire.
Seals have been treated at the North Yorkshire centre
The release of the pups, along with five grey seals, is the culmination of a project at the Scarborough Sea Life and Marine Sanctuary which has been immunising the seals against the lethal Phocine Distemper Virus.
The Yorkshire coast centre is one of the bases trailing a new vaccine to protect the animals after an outbreak of the disease wiped out thousands of seals on the east coast.
Experts believe the overall loses of the seals to the virus outbreak are around 22,000, similar to the 1998 wave which hit the population.
Animal care manager at the Scarborough Centre, Kieran Copeland, said: "The trials have proved a greater success than any of us dared hope."