If researchers developed a drug that could prevent t. brucei from undergoing antigenic variation, do you think it could be successful in eradicating african sleeping sickness? would the drug have to be administered at a certain point before or after infection in order to be ?

The answer is yes. Since trypanosomes do not enter cells, they are well exposed to antibodies of the immunity. They are not fully eradicated by the immune attack due to antigenic variations that enable some of its population to be unrecognized by antibodies. Keeping their surface antigen static would, therefore, improve eradication of Trypanosomiasis

The drug would be administered after infection. This is because the drug most likely works against the genes and metabolic/biological pathways of the trypanosomes responsible for their surface antigens. This would allow the immune system to easily form antibodies against the surface antigens. There would be no fear that the trypanosomes could vary their antigens hence evade the immune system.

The truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey