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Max Theiler 1899-1972

On the first anniversary of the passing away ofMax Theiler on August 11th , 1972, it is fitting topause for a moment to reflect on the life and workof this eminent scientist. It is not the intention toreview the many and varied scientific publicationswhich recorded the results of his investigations overthe years. In the memory of his contemporaries andof future generations his contribution to the studyof yellow fever virus and in particular to that ofarthropod-borne viruses in general will remainindelibly engraved.

Born on 30th January, 1899, at Daspoort inthe District of Pretoria, Transvaal, Max Theilerwas the youngest child of Arnold Theiler andEmma Jegge. During their early childhood, both atDaspoort and later at Onderstepoort, the Theilerchildren were encouraged to spend their time out ofdoors as field naturalists. They were taught, interalia by Professor Jansen and Austin Roberts, topreserve and study the various specimens whichthey collected and by example of their astute fatherthey were encouraged to develop their powers ofobservation.

As a scholar Ma x Theiler was consideredbright but suffered from the dubious advantage ofalways being the youngest member of his class. Hisjunior schooldays were spent at Loreto Convent,later, in senior school, he was a pupil at thePretoria Boy's High School. He commenced hisuniversity career by attending first RhodesUniversity, Grahamstown and later the SouthAfrican College, Cape Town, where he completedhis two year premedical course.

During the 1918 epidemic of influenza, allregistered medical students, if not ill themselves,where called upon to assist the few remaininghealthy doctors to minister the sick in the poorerareas of Cape Town. In those days the full coursein medicine was not available in this country and soit was that after the termination of World War I heentered St. Thomas London, where he qualified asa licensed practitioner.

The association between poverty and diseasewas again to make an impression on him for manyof the patients of St. Thomas Hospital wereresidents of the poorer areas of London. Whether itwas this association of poverty and disease orperhaps some unanswered problem in his enquiringmind which made him decide to change his studies,is not known; however, the decision to take a fourmonths course in tropical medicine and hygiene atthe London School of Tropical Medicine no doubtopened the door to his future career. It wasfortunate that Dr. O. Teague of the Ha vardMedical School at Boston, U.S.A., alsoattended the course. He offered MaxTheiler an appointment as an assistant. In 1922Max set sail for the United States and joined thestaff of the bacteriologist, Dr . Andrew Sellards, toform an association that was to last until 1930. Itwas not long before Sellards and Theiler foundthemselves involved in the study of yellow fever.

There is little doubt that the work andinterests of Max Theiler were influenced by hisexperience of tropical disease in Africa. During theperiod from 1926 to 1927, under the leadership of

R. Strong, Harvard sponsored an African expeditionto the Republic of Liberia , the Belgian Congo,Uganda and Kenya. Although yellow fever wasnot encountered by the expedition, Theilergained valuable experience in his particularassignment, which was the study of protozoalparasites of small mammals, as well as humantrypanosomiasis. He returned via South Africa ,where, unfortunately, there were no prospectsfor an appointment. Back in Boston Theilerresumed work on the nature of yellow fever on thefew strains available.

In 1928 Max Theiler married Lillian Graham;their son, Arnold, was born in 1929. Tragedyunfortunately struck the family through theuntimely death of young Arnold in a motor accidentin 1937. A daughter, Elizabeth, was born in 1939.

In 1928 Sellards returned from a visit to WestAfrica with the French strain of yellow fever fromDakar in a sample of infected, frozen monkey liver.Believing that yellow fever was of a bacterialaetiology, he carried on with his investigations andleft Theiler to follow up his own theory that thedisease was caused by a virus. Not only did Theilersucceed, but he was able to adapt the virus to braintissue of the Swiss strain of white mice by means ofserial passage. This finding led to the developmentof the mouse-protection test for identification ofyellow fever antibodies in human serum.

In 1930 Theiler was offered a post underWilliam Sawyer at the Rockefeller Foundationwhere he continued his work on yellow fever andother viruses. By this time the Foundation was wellestablished, with teams of scientists working in thefield in various parts of the world ; the prospects ofnew spheres of activity for Theiler were good .

As result of his efforts the now famous 17Dstrain was developed and in March 1937 Theilerand Smith reported that they had produced anattenuated virus which was an efficient immunizingagent. During the years 1937 to 1940 the vaccinewas tested under field conditions in Brazil withgreat success.

In July, 1936, Max Theiler attended theSecond International Biological Congress inLondon, where he reported on his studies on yellowfever. He was looking forward to this occasion andto hear his father 's comments on his achievements,for Sir Arnold was to have been present;unfortunately this was not to be, for Sir Arnoldpassed away while in London, before he hadpresented his paper.

A few years later an opportunity arose forTheiler to study the epidemiology of the disease inthe field, during a period spent in Columbia, at the

laboratory in Bogota and later in the foothills of theAndes .

.During the war years Theiler published hisstudies on many aspects of human poliomyelitiscarried out on mice , inclUding the discovery ofmouse encephalomyelitis virus , and onexperimental studies on the treatment of malariaincluding avian malaria. '

Public recognition of the work and successwhich had been obtained with the control of yellowfever came in 1951 with the award of the NobelPrize for Physiology and Medicine. The citationstated that the award took into account theattenuation of the virus and the subsequentdevelopment of a vaccine. The committee makingthe award emphasized that the award was based noton originality but an recognition of a service tomankind. To this quiet-spoken, unassuming manperhaps one of the most enjoyable days of his lifewas on August, 1955 , when he received thehonorary citizenship of the Theiler ancestral townof Hasle in Switzerwnd.

With the realization of their responsibilitiestowards international health, member states of theUnited Nations established the World HealthOrganization in 1958 , which meant that pri vatelysponsored philantropy in international problems fellaway. Gradually the Rockefeller InternationalHealth Board was phased out and eventuallyceased to operate in 1958. The Foundation,however, continued its investigations, placingemphasis on the study of viruses in general and thearthropod-borne viruses in particular. Sawyer hadretired in 1944 and in the course of time thedirectorship fell to Theiler. In 1950 he visitedSouth and East Africa to see what progress hadbeen made. The result of this exploratory visit wasthat Theiler presented to the Foundation a projectwhich aimed at a world-wide study of thearthropod-borne virus diseases of man and hisdomestic animals. This project was accepted , butbecause it was so vast , the Foundation could not beexpected to undertake all the investigatory workitself; it was proposed to enlist the co-operation ofinterested countries.

In the years that followed Theiler was to makea number of visits to Africa, India and SouthAmerica in order to establish laboratories andreview the progress made by the teams of scientistsworking in the tropics. A great deal of time wastaken up by administrative matters. yet Theilerfound much satisfaction in his work. He is quotedas saying "our virus programme is still flourishing.It is the most stimulating and worthwhileundertaking with which I have ever beenassociated , never a dull moment and alwayssomething new to keep us stimulated."

"The arthropod-borne viruses of vertebrates. 'being an account of the Rockefeller Foundationwork between 1952-1970," with Theiler as authorand W.G . Downs as co-author, finally went to pressin February, 1971.

In pursuance of its phasing out policy, theRockefeller Foundation was looking for anestablished university laboratory to continue itswork. Yale University was in need of a building forits School of Epidemiology and Public Health, asituation which led to the transfer of theresponsibility for the administration of thisorganization to the University. This move alsosuited Theiler, who became Professor ofEpidemiology until 1967, when upon reaching themandatory retiring age he was appointed ProfessorEmeritus.

In 1969 Theiler was still actively engaged, butby the end of 1970 he was obliged to content

himself with shortened visits to the laboratory inorder to keep his virus strains in order. Toward sthe end of 1971 he suffered a heart attack whichweakened him considerably and brought to an endhis enthusiastic and vigorous acti vities in the studyof the viruses of insects and man.

Besides the Nobel Prize and HonoraryCitizenship of the town of Hasle , Max Theiler hadreceived the Chalmers Medal of the Royal Societyof Tropical Medicine and Hygiene in 1939, theHarvard University Flattery Medal in 1945 and theLasker Award of the Lasker Foundation in 1949.

Theiler's work must be evaluated firstly in thelight of his discoveries concerning yellow fever at atime when techniques, which are now practisedas a routine in. virology, were in their infancy,secondly for his pioneer efforts to understandthe arthropod-borne viruses.