Childhood immunizations in the United States diphtheria patients die. Without treatment as many as half the patients can die from the disease. Pertussis is a highly contagious disease that is caused by the bacteria "Bordetella pertussis." The bacteria clings to cilia in the lungs and releases a toxin that damages the cilia and causes inflammation in the respiratory tract. Many infants are infected by older siblings or caregivers that don't even know they have the disease. The bacteria is spread through respiratory secretions, often through coughing or sneezing, or just from breathing in the bacteria while around someone who is infected. Unfortunately, the effectiveness of the
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