Pulmonary embolism is inferred by low blood oxygen levels.
Leslie Harold Collier -LRB- 9 February 1921 -- 14 March 2011 -RRB- was a scientist responsible for developing a freeze-drying method to produce a more heat stable smallpox vaccine in the late 1940s .. smallpox. smallpox. vaccine. vaccine. smallpox vaccine. smallpox vaccine. Collier added a key component , peptone , a soluble protein , to the process .. peptone. Peptide#Peptide classes. This protected the virus , enabling the production of a heat-stable vaccine in powdered form .. vaccine. vaccine. Previously , smallpox vaccines would become ineffective after 1 -- 2 days at ambient temperature .. smallpox. smallpox. The development of his vaccine production method played a large role in enabling the World Health Organization to initiate its global smallpox eradication campaign in 1967 .. smallpox. smallpox. vaccine. vaccine. World Health Organization. World Health Organization