Background: The effectiveness of rotavirus vaccines in low and very low birth weight infants (LBW and VLBW) weighing <2500 and <1500 g at birth, respectively, a high-risk population for severe rotavirus gastroenteritis, has not been well examined.
Methods: We analyzed inpatient commercial claims data for US children <5 years of age from July 2001 to June 2015. Claims for acute gastroenteritis (AGE) and rotavirus-coded hospitalizations and LBW, VLBW and normal birth weight (NBW) infants were identified. Receipt of rotavirus vaccine was defined using Current Procedural Terminology. Rate reductions were calculated using prevaccine (2001-2006) and postvaccine (2007-2015) annual AGE and rotavirus hospitalization rates.
Results: As of December 2014, rotavirus vaccine coverage was 87%, 82% and 64%, for NBW, LBW and VLBW infants, respectively. For 2014-2015, among NBW, LBW and VLBW children <5 years of age, AGE hospitalization rate reductions relative to the prevaccine introduction period were 60% [95% confidence interval (CI): 58%-61%], 64% (95% CI: 57%-70%) and 55% (95% CI: 39%-67%), respectively. Rotavirus hospitalization rate reductions were 91% (95% CI: 90%-92%), 98% (95% CI: 93%-100%) and 93% (95% CI: 70%-98%). Rotavirus vaccines resulted in a 62% (95% CI: 51%-71%), 72% (95% CI: 44%-86%) and 71% (95% CI: 7%-91%) reduction in AGE hospitalization rates comparing vaccinated versus unvaccinated NBW, LBW and VLBW children 3-23 months of age, respectively.
Conclusions: Rotavirus vaccines have substantially reduced AGE hospitalizations and are highly effective in LBW and VLBW infants, similar to NBW infants. Efforts to improve vaccination coverage, particularly in LBW and VLBW infants, should continue.