The document summarizes research on the efficacy of the Circovac vaccine in controlling PCVD (Porcine Circovirus Disease) under field conditions in Brazil. Two trials were conducted involving 1200 piglets total across two farms. Piglets vaccinated with Circovac at weaning showed lower wasting and mortality rates compared to non-vaccinated piglets. Vaccinated piglets also exhibited increased daily weight gain and improved feed conversion. Post-mortem examination found vaccinated piglets had significantly fewer lung lesions. The research concluded that Circovac vaccination of weaned piglets can effectively control PCVD and improve productivity on farms in Brazil.