Was employed initially as a ship's surgeon and subsequently as an increasingly senior surgeon in the Presidency National Hospital in Bengal. In 1804-5 the issue of vaccination - specifically against smallpox which was a virulent menace in the subcontinent at this time - was stirring passions in the Bengali presidency. John Shoolbred was the signatory of a declaration of the Native Inoculators in favour of Vaccine Inoculation and published for general information. His title was given as Suptd. General of Vaccine Inoculation.