The primary method of prevention for pertussis is vaccination. Evidence is insufficient to determine the effectiveness of antibiotics in those who have been exposed, but are without symptoms. Preventive antibiotics, however, are still frequently used in those who have been exposed and are at high risk of severe disease (such as infants). Vaccine Pertussis vaccines are effective at preventing illness and are recommended for routine use by the World Health Organization and the United States Centers for Disease Control and Prevention. The vaccine saved an estimated half a million lives in 2002. The multicomponent acellular pertussis vaccine is 71–85% effective, with greater effectiveness against more severe strains. However, despite widespread vaccination, pertussis has persisted in vaccinated populations and is today "one of the most common vaccine-preventable diseases in Western countries". The 21st-century resurgences in pertussis infections is attributed to a combination of waning immunity and bacterial mutations that elude vaccines. Immunization does not confer lifelong immunity; a 2011 CDC study indicated that protection may only last three to six years. This covers childhood, which is the time of greatest exposure and greatest risk of death from pertussis. An effect of widespread immunization on society has been the shift of reported infections from children aged 1–9 years to infants, adolescents, and adults, with adolescents and adults acting as reservoirs for B. pertussis and infecting infants who have had fewer than three doses of vaccine. Infection induces incomplete natural immunity that wanes over time. A 2005 study said estimates of the duration of infection-acquired immunity range from 7 to 20 years and the different results could be the result of differences in levels of circulating B. pertussis, surveillance systems, and case definitions used. The study said protective immunity after vaccination wanes after 4–12 years. One study suggested that the availability of vaccine exemptions increases the number of pertussis cases. 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 pertussis even though they may have only mild symptoms or none at all. Pertussis infection in these persons may be asymptomatic, or present as illness ranging from a mild cough to classic pertussis with persistent cough (i.e., lasting more than 7 days). Even though the disease may be milder in older persons, those who are infected may transmit the disease to other susceptible persons, including unimmunized or incompletely immunized infants. Older persons are often found to have the first case in a household with multiple pertussis cases, and are often the source of infection for children.
Whooping cough
Common cold
Croup
Post-viral cough
Bronchorrhea
Katrina cough
Dust pneumonia
Allergic rhinitis