This is the 4217th most frequent Portuguese word.
vacina
A "vacina" is a vaccine, a substance used to stimulate the immune system and provide immunity against a specific disease.
Here, 'vacina' is used to refer to a specific type of vaccine that protects against the flu, showcasing its direct and literal medical application.
Eu tomei a vacina contra a gripe este ano.
I received the flu vaccine this year.
In this sentence, 'vacinas' is used in the plural form to denote vaccines in general, focusing on the broader context of medical research and development.
A pesquisa sobre novas vacinas está avançando rapidamente.
Research on new vaccines is progressing rapidly.
Here, 'vacina' is used in a generic sense to represent the concept of vaccination as an important medical milestone.