Police said the accident happened at 4am in Tambon Sanab Tueb in Wang Noi district.
The van driver, Somboon Vattanakit, told police that a car cut in front of his van at a very close distance, so he swerved to the left and crashed into the concrete base on the roadside.
Somboon and four staff members of a medical team were injured. They were identified as Thawatchai Klinsukhon, Haruethai Sathanbua, Pussadee Wannarat and Sudarat Paengkaew.
The five were rushed to Wang Noi Hospital.
The team was taking donated organs from Chaiyaphum to Praram 9 Hospital when the accident occurred.