Major Finding: Nearly three-quarters of infants aged 5 months (72%) are receiving at least one dose of rotavirus vaccine.
Data Source: Analysis of data from 23,532 infants enrolled at one of eight Immunization Information System sentinel sites.
Disclosures: Immunization Information System sentinel sites receive support from the Centers for Disease Control and Prevention.
Rotavirus vaccination coverage among infants aged 5 months is averaging 72% nationwide, results from a recent analysis of eight Immunization Information System sites demonstrated.
However, vaccination rates varied widely between sites, and site-specific rotavirus vaccine coverage remained an average of 13 percentage points lower than that of diphtheria, tetanus, and acellular pertussis (DTaP) vaccine and 7-valent pneumococcal conjugate vaccine (PCV7) in June 2009.
“[Rotavirus vaccine] is unique among vaccines recommended during infancy in having a maximum age for beginning the series,” researchers led by Diana L. Bartlett of the Immunization Services Division at the National Center for Immunization and Respiratory Diseases, Atlanta, reported. “This age restriction could account, in part, for the lower RV coverage because an infant aged 15 weeks–5 months could still receive a first dose of DTaP or PCV7 (but not RV), according to ACIP recommendations.”M
Ms. Bartlett and her associates analyzed data from eight Immunization Information System (IIS) sentinel sites to assess trends in coverage with one or more doses of rotavirus vaccine between June 2006 and June 2009 among infants aged 5 months and to compare RV coverage in the second quarter of 2009 with that of DTaP and PCV7 (MMWR 2010:59:521–4).
Supported by the Centers for Disease Control and Prevention, IIS sentinel sites are population based and cover more than 1.8 million children younger than age 6. The sites are unique for their high health care provider participation (greater than 85%), child enrollment (more than 85% are younger than age 19), and timely capture of administered vaccines (more than 70% of doses are reported to the IIS within 30 days of vaccination). Sites included in the analysis since 2008 were located in Arizona, Colorado, Michigan, Minnesota, New York City, North Dakota, Oregon, and Wisconsin. Four of these sites have continuously served as IIS sentinel sites since 2004 (Arizona, Michigan, Minnesota, and Oregon).
As of June 30, 2009, 23,532 infants aged 5 months were enrolled at the eight IIS sites. After introduction of the RV vaccine, coverage among infants enrolled at the four continuously serving IIS sentinel sites rose to 50%–60% within the first year, and steadily thereafter, to 74% by the second quarter of 2009. As of June 20, 2009, RV coverage at all eight IIS sentinel sites averaged 72%. Colorado had the lowest rate of coverage (48%) while North Dakota had the highest (86%).
At the same time, coverage for one or more doses of DTaP or PCV7 vaccines at all eight IIS sentinel sites was 85%, or 13% higher than RV coverage. New York had the lowest coverage rates for DTaP and PCV7 (71% and 72%, respectively), while North Dakota had the highest coverage rate for DTaP (93%) and Michigan had the highest coverage rate for PCV7 (91%).
The researchers acknowledged certain limitations of the study, including the fact that coverage rates of DTaP and PCV7 at some IIS sites “were lower than expected based on 2008 [National Immunization Survey] data. These lower rates could result from persons who left the IIS sentinel site area before receipt of their vaccination, but who were still counted as enrolled and unvaccinated. Second, although IIS sentinel sites data are monitored for accuracy and completeness, RV might be less reliably entered into IIS than other infant vaccines because it is a relatively new vaccine. This could result in an underestimate of RV coverage levels.”
They concluded by noting that continued monitoring of RV coverage “will be crucial to provide information useful to policy makers and help focus efforts to achieve RV rates at least as high as other routinely recommended vaccines for U.S. infants.”