sentence1: Last year , there were shortages of shots for diphtheria-tetanus-whooping cough , measles-mumps-rubella , pneumococcal disease , tetanus and chicken pox nationally .
sentence2: In the past two years scientists say there have been vaccine shortages for diphtheria-tetanus-whooping cough , measles-mumps-rubella , pneumococcal disease , tetanus and chicken pox .