You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did the hpv vaccine come out in us?" whose answer is 2009.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did the hpv vaccine come out in us
Useful Output:

Doc 1: Szarewski goes on to be principal investigator in the development of the bivalent HPV vaccine. In 1999 the first vaccine against rotavirus, the most common
Doc 2: Since the HPV vaccine was licensed in 2006, research has been done all over the world. It shows that the vaccine is safe and prevents cancer. Read more about
Doc 3: Gardasil 9 has, since 2016, been the only HPV vaccine used in the United States. It prevents infection with the following nine HPV types:
Doc 4: The Canadian Immunization Guide is a comprehensive resource on immunization. The guide consists of 54 chapters organized into 5 parts.
Doc 5: History: On August 25, 2004, as a result of routine testing required by the FDA, Chiron Corporation, located in the U.K. and one of two suppliers of inactivated