Pertussis vaccine and new mutations in the pathogen that existing vaccines are unable to effectively control. Some studies have suggested that while acellular pertussis vaccines are effective at preventing the disease, they have a limited impact on infection and transmission, meaning that vaccinated people could spread the disease even though they may have only mild symptoms or none at all. For children, immunizations are commonly given in combination with immunizations against tetanus, diphtheria, polio, and haemophilus influenzae type B at two, four, six, and 15–18 months of age. A single later booster is given at four to six years of age (US
Fatty liver disease Fatty liver disease Fatty liver disease (FLD), also known as hepatic steatosis, is a condition where excess fat builds up in the liver. There are two types non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease. NAFLD is made up of simple fatty liver and non-alcoholic steatohepatitis (NASH). Risk factors for NAFLD include diabetes, obesity, and older age. The condition is also associated with other diseases that influence fat metabolism. It is difficult to distinguish alcoholic FLD, which is part of alcoholic liver disease, from nonalcoholic FLD (NAFLD), and both show microvesicular and macrovesicular fatty changes at different stages. Fatty