Prevalence, Risk Factors and Vaccine Response against Hepatitis B in People Aged 50 Years or Older oleh Luana Rocha da Cunha Rosa, Leyla Gabriela Verner Amaral Brandão, Winny Éveny Alves Moura, Lays Rosa Campos, Grécia Carolina Pessoni, Juliana de Oliveira Roque e Lima, José Cássio de Moraes, Megmar Aparecida dos Santos Carneiro, Sheila Araújo Teles, Karlla Antonieta Amorim Caetano