The pace of the whooping cough epidemic that’s tallied more than 2,600 cases across the state appears to finally be slowing.Dr. Alan Melnick, Clark County health officer, said Wednesday that while new cases continue to pop up in the county and across the state, the rapid pace experienced earlier this year appears to be losing steam.Last week, the state reported 47 new cases of the illness — significantly less than the 251 cases reported during the peak week of the outbreak (May 13-19).From Jan. 1 to June 23, health officials confirmed 2,647 cases of whooping cough. That’s compared with just 187 cases during the same time period in 2011.In Clark County, health officials have confirmed 186 cases of whooping cough since Jan. 1. That’s six times the number of cases this time last year, according to county records.Clark County Public Health staff investigated every local case, interviewing the ill person and identifying others who may have been exposed, Melnick said.During those investigations, health officialslearned that some kids with the illness were returning to school before completing five days of antibiotics, meaning they were still contagious, Melnick said. In response, public health staff sent notifications in April and May to local medical providers, alerting them to the pattern, he said.Health officials and medical groups across the state have also ramped up efforts to get people vaccinated against the respiratory illness.The county and Kaiser Permanente offered free whooping cough vaccinations to uninsured and underinsured adults and children throughout the month of June. The final two clinics are 6:30 to 8:30 p.m. today and Friday at Kaiser Permanente Cascade Park Medical Office, 12607 S.E. Mill Plain Blvd., Vancouver.