Two school-age children from Gaines County who had measles were hospitalized in Lubbock, state officials said.

Two children were hospitalized with measles in West Texas the same month the highly contagious respiratory illness was also found in two Houston residents.

Two of the four cases are in Lubbock, which hasn’t seen a case in more than 20 years. Measles vaccination rates in Texas have fallen over the last four years.