Merck Animal Health, part of global pharmaceutical giant Merck, is buying privately owned Harrisvaccines, the companies said in a joint announcement. Merck said it has a “robust portfolio of vaccines across all animal species” and Harrisvaccines’ specialty of vaccines for food-bearing animals and pets would strengthen the Merck line. Harrisvaccines was the first company to develop a vaccine for the Porcine Epidemic Diarrhea virus. It developed a vaccine this year for avian influenza and won a contract to supply a government stockpile.Terms of the deal were not announced. The companies said they expect to close the transaction by the end of the year.