Decline in cases of rotavirus gastroenteritis presenting to The Children's Hospital of Philadelphia after introduction of a pentavalent rotavirus vaccine.
A pentavalent rotavirus vaccine for infants became available in the United States in February 2006. By 2007, vaccination rates nationwide were estimated to be approximately 50%. We studied the effectiveness of the vaccine in a real-world setting outside of a clinical trial. All children presenting to The Children's Hospital of Philadelphia with acute gastroenteritis have been monitored for the presence of rotavirus antigen in the stool by enzyme-linked immunosorbent assay (ELISA [followed by genotyping if ELISA positive]) since the 1994-1995 epidemic season, presenting a unique opportunity to assess the impact of the recently introduced vaccine. The annual number of community-acquired cases over the preceding 13 years had approached or exceeded 100, with 271 cases in 2005 to 2006 and 167 cases in 2006 to 2007. In the 2007-2008 season, only 36 community-acquired cases were identified, representing an 87% reduction from the same period in 2005 to 2006. G3 was the predominant serotype, accounting for 15 community cases (42%). Our study is limited by its observational design using historical comparisons. Nonetheless, the abrupt decline in rotavirus gastroenteritis cases during the 2007-2008 season likely resulted from vaccination. Because protection rates appeared to have exceeded vaccination rates, herd immunity may have contributed to some degree to the effectiveness of the vaccine.
Clark
H Fred
HF
Division of Infectious Diseases, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA. clarkf@email.chop.edu
Lawley
Diane
D
Mallette
Laura A
LA
DiNubile
Mark J
MJ
Hodinka
Richard L
RL
D000956:Antigens, Viral / Q000032:analysis; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000737:chemistry / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000517:prevention & control*; D005838:Genotype; D006801:Humans; D032521:Immunity, Herd; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D015143:Philadelphia / Q000453:epidemiology; D012367:RNA, Viral / Q000235:genetics; D012401:Rotavirus / Q000145:classification / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000276:immunology*
D000956:Antigens, Viral; D012367:RNA, Viral; D022243:Rotavirus Vaccines