Merck & Co., manufacturer of Vioxx, announced it will make the first payment of $500 million on Aug. 6 into a fund to settle claims by plaintiffs injured by the drug. The settlement fund will eventually total $4.85 billion. By providing the funding for settlements, Merck waives its right to walk away from the settlement deal, originally established in May. More than 60,000 people currently have registered a claim that Vioxx caused heart attack or stroke. Payments to claimants will begin before the end of August.