There are 52 distinct types of adenovirus. Various types of adenovirus can cause respiratory illness, gastroenteritis, conjunctivitis, bladder infections, and rashes. Adenoviruses are spread through direct contact, fecal-oral transmission, and occasionally water-borne transmission. Some types can establish persistent infections in the tonsils, adenoids, and intestines without causing any visible symptoms; however, those infected can continue to spread the virus to others for months or years without realizing they are even infected.
This section will be concerned with the respiratory illnesses that can be caused by adenovirus type 4 and type 7. In the United States, acute respiratory disease (ARD) is often associated with these two adenovirus types. Symptoms include fever, sore throat, cough, conjunctivitis, runny nose, headache, and pneumonia. The incubation period can vary between 2 and 14 days, with an average of 5-8 days. Symptoms generally last 3 to 10 days.
Adenovirus has been identified as a cause of severe epidemics of ARD in military recruit populations. Studies have shown that up to 80% of recruits develop adenovirus infections, and 20% require hospitalization. Of those hospitalized and found to have adenovirus respiratory infections, adenovirus type 4 and type 7 accounted for 60% of the cases.
From 1971 until 1999, US military recruits routinely recevied a live, oral adenovirus vaccine against types 4 and 7. In 2011, the Food and Drug Administration (FDA) approved a new adenovirus vaccine that protects against types 4 and 7. This is a live, non-attenuated oral vaccine consisting of two enteric-coated tablets.
Product: Adenovirus Type 4 and Type 7 Vaccine, Live, Oral
Manufacturer: Barr Labs, Inc. (Distributed by Teva Pharmaceuticals USA, Inc.)
Year licensed: 2011
Large-scale studies of the new vaccine in U.S. military recruits showed high efficacy rates in preventing wild type 4 adenovirus-associated febrile acute respiratory disease and inducing neutralizing antibody to type 7 adenovirus.