You will be given a definition of a task first, then some input of the task.
Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

Question: Does hepatitis B virus vaccination booster provide additional protection in adolescents : a cross-sectional school-based study?
Answer: HBV booster strategy at 15years of age was the main contributor to the unique age-related phenomenon of anti-HBs seropositivity rate and titer. No increase in HBsAg seropositivity rates within different age groups was observed. Vaccination with plasma-derived HBV vaccines in infancy provided higher anti-HBs seropositivity at 15-18 years of age. Overall booster response rate was 92.5% and indicated that intact immunogenicity persisted at least 15years after primary HBV vaccination in infancy. Booster vaccination of HBV did not confer additional protection against HBsAg carriage in our study.
Output:
no