Evaluation of hepatitis B vaccine immunogenicity among older adults during an outbreak response in assisted living facilities

► The immunogenicity of monovalent hepatitis B vaccine was evaluated among older adults during an outbreak response. ► The overall vaccine response rate was 33%. ► Age was only significant predictor of seroprotection. ► Populations at risk of hepatitis B are more likely to benefit from vaccination at earlier ages. ► Use of double dose or extra-doses of hepatitis B vaccine might be alternative considerations among older adults.