Pertussis vaccine wholesale in the developing world at a cost of 15.41 USD per dose as of 2014. Acellular pertussis vaccine (aP) with three or more antigens prevents around 85% of typical whooping cough cases in children. It has higher or similar efficacy to the previously-used whole cell pertussis vaccine, however the efficacy of the acellular vaccine declines faster. Acellular vaccines also cause fewer side effects than whole cell vaccines. Despite widespread vaccination, pertussis has persisted in vaccinated populations and is one of the most common vaccine-preventable diseases. The recent resurgence in pertussis infections is attributed to a combination of waning immunity
Tay–Sachs disease Researchers are looking at gene therapy or enzyme replacement therapy as possible treatments. Tay–Sachs disease is typically first noticed in infants around 6 months old displaying an abnormally strong response to sudden noises or other stimuli, known as the "startle response". There may also be listlessness or muscle stiffness (hypertonia). The disease is classified into several forms, which are differentiated based on the onset age of neurological symptoms. Until the 1970s and 1980s, when the disease's molecular genetics became known, the juvenile and adult forms of the disease were not always recognized as variants of Tay–Sachs disease. Post-infantile Tay–Sachs was