Rotavirus Vaccination, Postlicensure Safety Monitoring, Intussusception

Journal of Infectious Diseases
Volume 206 Issue 1 July 1, 2012

Michelle Clarke and H. Marshall
Editor’s choice: Rotavirus Vaccination for Prevention of Serious Acute Gastroenteritis and the Importance of Postlicensure Safety Monitoring
J Infect Dis. (2012) 206(1): 3-5 doi:10.1093/infdis/jis318
(See the major article by Yen et al, on pages 41–8.)

With the ability to save millions of lives each year in both the developed and developing nations, vaccination against childhood infectious diseases is a priority area for global health. An essential aspect of the success of any vaccination program is the careful monitoring following implementation to ensure that the benefits of the program outweigh any risks to the recipients or the community. Infant rotavirus vaccination programs are an important example of the collaborative expertise required for effective and timely monitoring and reporting of any adverse events following implementation. Rotavirus vaccines have been instrumental in reducing morbidity from rotavirus infection. Prior to the introduction of rotavirus vaccine, it is estimated that >500 000 rotavirus-related child deaths occurred globally each year [1]. Studies assessing the impact of rotavirus vaccine on incidence of rotavirus hospitalizations have occurred in numerous countries, including Australia and the United States, with dramatic reductions in the incidence of rotavirus hospitalizations (up to 80% reduction) shown following implementation of the rotavirus vaccination programs and suggestions of herd immunity benefits for older, unvaccinated populations [2–6]. The development of vaccines to prevent serious infectious diseases has been a global triumph, but large-scale postlicensure studies are essential to ensure that vaccination programs deliver the anticipated benefits.

In response to the overwhelming global burden of rotavirus infections, particularly in children aged <5 years, a live, attenuated tetravalent rotavirus vaccine (RotaShield) was licensed for routine use in infants in 1998, before being withdrawn in 1999 due to concerns about an increased risk of intussusception in vaccine recipients …

Catherine Yen, Jacqueline E. Tate, Claudia A. Steiner, Margaret M. Cortese, Manish M. Patel, and Umesh D. Parashar
Editor’s choice: Trends in Intussusception Hospitalizations Among US Infants Before and After Implementation of the Rotavirus Vaccination Program, 2000–2009
J Infect Dis. (2012) 206(1): 41-48 doi:10.1093/infdis/jis314

Background. Although US data have not documented an intussusception risk with current rotavirus vaccines, international data indicate  a possible low risk, primarily after the first dose.

Methods. Among infants in 26 US states comprising 75% of the birth cohort, we examined age-specific trends in population-level intussusception hospitalization rates before (2000–2005) and after (2007–2009) rotavirus vaccine introduction.

Results. Compared with 2000–2005 (35.3 per 100 000), the rate was greater in 2007 (39.0 per 100 000; rate ratio [RR], 1.10; 95% confidence interval [CI], 1.04–1.18), similar in 2008 (33.4 per 100 000; RR, 0.95; 95% CI, .89–1.01), and lower in 2009 (32.9 per 100 000; RR, 0.93; 95% CI, .87–.99). Among infants aged 8–11 weeks, compared with 2000–2005 (6.9 per 100 000), a small, significant increase was observed in each of 2007 (11.4 per 100 000; RR, 1.64; 95% CI, 1.08–2.50), 2008 (12.2 per 100 000; RR, 1.76; 95% CI, 1.17–2.65), and 2009 (11.0 per 100 000; RR, 1.59; 95% CI, 1.04–2.44).

Conclusions. Following rotavirus vaccine introduction, a small increase in intussusception rates was seen among US infants aged 8–11 weeks, to whom most first doses of vaccine are given; no sustained population-level change in overall rates was observed.