Detailed Instructions: 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.
Problem:Question: Are health care workers in Pearl River Delta Area of China vaccinated adequately against hepatitis B : a retrospective cohort study?
Answer: The vaccination rate was a disappointingly low among HCWs in Pearl River Delta Area of China. HCWs working in infectious diseases departments and technicians were at particularly likely to have been infected with HBV. A concerted effort is needed to bring vaccination rates up among Chinese HCWs in Pearl River Delta Area of southern China.
Solution:
no