For citizens of most countries, a valid passport will suffice to enter Peru for this conference. For citizens from a few countries however, a visa is required. Check whether you need a visa via the list of required visa via the website of the Peruvian Ministry of Foreign Affairs (pdf, in Spanish), or check https://www.peru.travel/plan-your-trip/entering-peru.aspx and make sure to apply well in time for a visa in case you need one. In case of doubt, contact your nearest Peruvian embassy or your nearest consulate of Peru to make sure.
The type of vaccination needed or recommended depends on your personal medical history and whether you will stay for the conference only or for a more extended period. Read more about this at https://www.peru.travel/plan-your-trip/entering-peru.aspx
All participants are held to arrange adequate health care and travel insurance by themselves and at their own costs. This also applies to participants eventually being offered a participation grant. The Conference Organizers nor the IASC are liable for any costs not covered by health or travel insurance or in case a participant has not arranged proper insurance.