A nurse loads a syringe with a vaccine against hepatitis at a free immunization clinic for students before the start of the school year, in Lynwood, California August, 27, 2013. Nurses are immunizing children in preparation for the first day of public school on September 3. The clinic offers the mandatory vaccinations for school children against diphtheria, tetanus, pertussis, polio, hepatitis B, MMR (measles, mumps, rubella) and chickenpox as well as some optional ones. AFP PHOTO / Robyn Beck (Photo credit should read ROBYN BECK/AFP/Getty Images)(credit: ROBYN BECK/AFP/Getty Images)