>>216565672 (OP)
Medawar won it, and was technically Brazilian.
César Lattes would have won it, as he was co-author of the winning paper. However, in those days only the leader of the research group got the prize. By modern rules, he would have won it.
And then you have the biases. For example, Carlos Chagas and Vital Brazil were worthy of a Nobel, yet never got one. Meanwhile, the Portuguese guy who invented lobotomy did, which is of course a bit of an embarrassment to the Academy.
Same thing in literature. Brazilian authors take a long time to be translated, so they are often dead by the time they become well-known. Lispector is now very famous, yet by the time she died nobody knew her outside Brazil. When Machado de Assis and Euclides da Cunha died I don't think they had ever been translated. Guimarães Rosa was translated, but it was famously a very bad translation. Meanwhile, the Academy gave the prize to Bob Dylan and Bertrand Russell, which is frankly ridiculous, they're not even actual literary writers.