Full, partial immunization with rotavirus vaccine highly protective

Staat MA. Pediatrics. 2011;doi:10.1542/peds.2010-3722.

Full or partial immunization with the pentavalent rotavirus vaccine was highly protective against rotavirus-associated hospitalizations and ED visits, according to new study findings.

A study by Mary Allen Staat, MD, MPH, and colleagues showed that immunization with the pentavalent rotavirus vaccine (RV5; RotaTeq, Merck) protected infants from severe rotavirus disease, even if the children received only part of the three-dose series. In addition, protection persisted through the second year of life.

Mary Allen Staat

Using the acute gastroenteritis control group, vaccine effectiveness for the three-dose series during the first year of life was 86% (CI, 31-97), and 90% (CI, 65-97) during the second year of life. These results support the findings from two post-licensure studies on vaccine effectiveness.

The active, prospective, population-based surveillance for acute gastroenteritis and acute respiratory infection included patients who were recruited from inpatient and ED settings for the case-control evaluation of vaccine effectiveness in three US counties from January 2006 to June 2009. Children with laboratory-confirmed rotavirus acute gastroenteritis were matched according to date of birth and onset of illness to two sets of controls: children with rotavirus-negative acute gastroenteritis and children with acute respiratory infection. The main outcome measure was vaccine effectiveness with complete (three doses) or partial (one or two doses) RV5 vaccination.

“We found good protection from less than a full three-dose series of RV5, with levels of 85% and 81% for one dose and 79% and 88% for two doses of vaccine, depending on the control group used.” The researchers wrote. “Because some children may not receive all three recommended vaccine doses, it is reassuring that partial vaccination was effective; however, whether the effectiveness is long-lasting could not be determined in our study.”

The study investigators said additional monitoring is needed to assess genotype-specific effectiveness, duration of protection from vaccination, and the effectiveness of the monovalent rotavirus vaccine (RV1; Rotarix, GlaxoSmithKline).

Disclosures: Dr. Staat received past research funding from Merck Research Laboratories and current funding from GlaxoSmithKline. She also served on the Rotavirus Advisory Board for Merck and GlaxoSmithKline. Study co-researchers reported receiving funding from GlaxoSmithKline, MedImmune, Merck, Sanofi-Pasteur, Novartis and Wyeth.

Vaccinations are the most important, most well studied and one of the very few interventions we provide as pediatricians with a clear beneficial effect as measured by outcome data. Vaccinations are unquestionable the superstars of pediatric care and have transformed not only the overall health of children but the daily practice of pediatrics. Obviously, as with all medical interventions, vaccinations have risks and the balance between benefits, public and individual, and the corresponding risks is what we in the office-setting spend an enormous amount of time on educating the public - one family at a time.

The saga of rotavirus vaccine is rather long and frustrating. First released and then quickly withdrawn at the very end of the 1990s because of an association with intussusception, many pediatricians were reluctant to provide the newer generation of the vaccine and those providing the vaccine were concerned over the narrow age range over which the vaccine was approved. Recent studies have both demonstrated vaccine efficacy as well as a continued small risk of intussusceptions associated with the vaccine though with some evidence that vaccination might reduce the absolute rate of intussusception in a population. Finally it appears that data will be able to drive a more sophisticated discussion of risk and the obvious benefits of rotavirus vaccination. If only that discussion could also take place in a wider sphere than my exam room.

The present study by Staat and colleagues demonstrates the effectiveness of the pentavalent rotavirus vaccine against severe rotavirus disease over the first and second year of life when given in full as well as partial series. This is a real world, U.S. based study that addresses the efficacy of vaccine as used in routine clinical care, warts and all. The results should be very reassuring to clinicians.

– William T. Gerson, MD
Infectious Diseases in Children Editorial Board member

Disclosures: Dr. Gerson reports no financial disclosures.

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