Pneumococcus is a type of bacteria known scientifically as Streptococcus pneumoniae. It is a common cause of pneumonia, a lung infection, as well as other illnesses like meningitis and sinusitis. Pneumococcus can spread through respiratory droplets when an infected person coughs or sneezes. Vaccines are available to help prevent infections caused by pneumococcus. These vaccines are especially important for young children, the elderly, and individuals with weakened immune systems. Early diagnosis and treatment with antibiotics can effectively manage infections caused by this bacterium.