Eye to Eye S01E03 - Line of Defence

Tonight Eye to Eye tells the story of the medical officers of the Port of London Health Authority who stand on guard as the first line of defence against infectious disease.
A ship from Asia is heading for the Channel; one of the passengers is sick; 'query smallpox' is the message sent by the ship's surgeon; in thirty-six hours they will be in London, capital of a country of fifty million people, only a quarter of whom are vaccinated.