A county health administrator has resigned after his department mistakenly administered the wrong dosage of Moderna’s COVID-19 booster shot to about 200 people last month. The Mercer County Health Department’s board accepted administrator Roger Topping’s resignation this week. During an Oct. 28 vaccine clinic, full doses of the Moderna booster were given out instead of the recommended half doses. Dr. Ayne Amjad, the state’s health officer, said the full dose is not harmful but could cause a stronger side effect in some people. Topping had said the department did not know half dosages should have been administered. Vaccine clinics operated by the Mercer County Health Department have been stopped temporarily.