The FDAs Vaccines and Related Biological Products Advisory Committee gave a positive opinion on the efficacy and safety of Rotateq ( rotavirus vaccine, live, oral, pentavalent ), an investigational vaccine developed to prevent rotavirus gastroenteritis.
Rotavirus gastroenteritis is the most common cause of severe dehydrating diarrhea in infants and young children, causing an estimated 250,000 emergency department visits and 500,000 visits to physicians offices each year in the United States.
Although symptoms vary, those typically associated with rotavirus gastroenteritis include vomiting, fever, abdominal pain and watery diarrhea which can persist for three to nine days.
The severity of rotavirus gastroenteritis ranges from asymptomatic to dehydrating gastroenteritis that can be fatal.
The incidence of rotavirus is similar in developed and developing countries, which suggests that differences in environment ( e.g., clean water, hygiene or sanitation ) do not prevent this disease.
During the first few years of life, a child typically has several rotavirus infections. The highest rates of gastroenteritis are generally in children under two years of age, who are also at the greatest risk for severe disease. Nearly all children will be infected with rotavirus by age five. There are several different serotypes of rotavirus and the prevalence of these serotypes varies by geographic region and can change from season to season. Children gradually develop immunity against different strains of the virus after several infections.
The Advisory Committee also recommended that Merck continue to develop and conduct post-licensure studies to assess the safety and efficacy of Rotateq if it is approved for use.
The Advisory Committee's recommendation was based on data presented from Phase III clinical trials including the Rotavirus Efficacy and Safety Trial ( REST ).
The REST trial was conducted from 2001 to 2004 worldwide.
A total of 70,301 healthy infants 6 to 12 weeks old were enrolled in 11 countries to receive 3 doses of oral rotavirus vaccine or placebo at 4 to 10 week intervals.
Acute gastroenteritis was an episode of forceful vomiting and/or >3 watery or looser-than-normal stools within a 24-hour period and rotavirus antigen detection by electroimmunoassay ( EIA ) with confirmation by PCR (polymerase chain reaction).
The analysis of hospitalization and emergency department ( ED ) visits showed six hospitalizations and 14 ED visits among children who were given the vaccine, a decrease of 95.8% and 93.40%, respectively.
Analysis of study data also showed an 86.6% reduction in work loss for parents.
Source: Merck, 2005