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 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.
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.