Impressive data on likely RotaTeq impact; Rotarix ACIP recommendation added

A good amount of news about rotavirus vaccination in the U.S. came out of Atlanta yesterday. First, a CDC report issued as an MMWR Early Release detailed encouraging data on trends regarding the impact of rotavirus. Titled "Delayed onset and diminished magnitude of rotavirus activity -- United States, November 2007-May 2008," the report examines data from clinical laboratories as to the frequency and timing of confirmed rotavirus samples during the rotavirus season currently underway.

In addition to seeing a delay of 2-4 months in the start of this year's rotavirus season, the report states that the number of positive tests for rotavirus was "substantially lower during the 2007-08 rotavirus season than during any of the prevaccine seasons." These trends coincide with increasing use of RotaTeq, Merck's rotavirus vaccine, approved in 2006. (Despite being the most likely explanation, both the report and an accompanying CDC press release acknowledge that the role of the vaccine cannot be stated definitively from these data alone.)

If these changes are, in fact, attributable to RotaTeq, there are also early signs that the benefit of vaccination may extend beyond those vaccinated to the community-at-large. The MMWR piece explains:

"Because the changes in rotavirus activity appear more pronounced than might be attributed to direct protective effects of vaccination alone, the results of this analysis suggest that vaccination of a proportion of the population might offer indirect benefits to unvaccinated children (i.e., herd immunity) by reducing transmission of rotavirus in the community. "

Needless to say, more data will be needed to see whether this positive trend continues in future years, as well as whether the declines in positive tests for rotavirus correspond with decreases in rotavirus-induced hospitalizations and deaths as vaccination programs proceed.

Here's coverage from the Los Angeles Times and the Washington Post, and a press release by Merck touting the positive news.

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In other rotavirus vaccine news, GSK's Rotarix, approved by FDA in April (as we noted previously), was added yesterday by the Advisory Committee on Immunization Practices to its universal recommendation for infants. No preference was stated between the two vaccines by ACIP. Here's a story on the recommendation (technically not official until published in MMWR) by the Associated Press.

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Unrelated to rotavirus, the ACIP also voted to add recommendations for two combination vaccines as options for parents and physicians: Sanofi Aventis' Pentacel (DTaP, polio, Hib) and GSK's Kinrix (DTap, polio), both of which would reduce the total number of injections needed to complete the recommended vaccination series. This Reuters story has more.

From CDC: Zoster recommendations, measles outbreak, post-vaccine fainting, and more

Several items of note have been released by CDC in recent weeks, including:

• "Prevention of Herpes Zoster: Recommendations of the Advisory Committee on Immunization Practices" -- The publication making official the recommendations regarding the use of Merck's zoster vaccine, Zostavax. In short, routine vaccination of all persons age 60 and older is advised, except for those with specific contraindications.

• "Measles--United States, January 1-April 25, 2008" -- A report on the unexpectedly large number of measles cases confirmed in the U.S. in the early months of the 2008. Of the 64 cases, 63 occurred in people who were unvaccinated or were of undocumented vaccination status. The report notes that a large number of the cases occurred in children whose parents had received philosophical exemptions from vaccine requirements.

• "Syncope After Vaccination--United States, January 2005-July 2007" -- The arrival of newly recommended adolescent vaccines has led to an increase in fainting, particularly among 11-18 year old females, CDC reports. One fatality has been confirmed as a result of a head injury caused by a fainting-induced fall. The report reiterates a previous recommendation to observe patients for 15 minutes following vaccination to reduce the risk of falls and injuries caused by fainting.

• NCIRD Annual Report -- The 2008 annual report of the National Center for Immunization and Respiratory Diseases -- the administrative home of most of CDC's vaccination-related activities -- was released last month. Of interest to those interested in the breadth of CDC's immunization activities, it its own words.
  

Revised adult immunization schedule released; Hep A news and recommendations

Friday's MMWR included a newly updated adult recommended immunization schedule -- PDF available here. As the introductory material details, changes made to last year's schedule are fairly minor, notwithstanding the addition of zoster vaccine (recommended for adults 55+) and an expanded recommendation for varicella (now recommended for all adults without evidence of immunity).

The same issue of MMWR included updated ACIP recommendations on postexposure prophylaxis for those exposed to Hepatitis A virus. The recommendations address the relative merits of Hep A vaccine versus immune globulin (IG) as a postexposure strategy, the subject of a randomized clinical trial ("Hepatitis A Vaccine versus Immune Globulin for Postexposure Prophylaxis") and an editorial ("Another Success for Hepatitis A Vaccine") in this week's New England Journal of Medicine.

CDC National Immunization Survey Results Released

On Friday, the latest issue of MMWR included the 2006 data from the National Immunization Survey, the most reliable source for information on vaccination rates nationwide. MMWR (pdf) includes two reports. One looks at children age 19-35 months (the traditional study population of NIS since its inception in 1994). The other surveys teenagers age 13-17 years (a new 'spin-off' study appropriately dubbed NIS-Teen).

In the infant/toddler population, the news appears to be quite good. Based on a sample of over 21,000 children, 77% had received the full recommended series of vaccinations in 2006, a slight (though statistically insignificant) increase over 2005's figure of 76.1%. This year's data moves closer to the Healthy People 2010 goal of 80% coverage for the recommended series.

That said, there is a great variation in vaccination rates among states and clear differences among races and socioeconomic status. 73.9% of African-American children have received the complete series of recommended vaccinations, compared to 77.9% of white children and 77.4% of Hispanic children.

An accompanying CDC press release somewhat awkwardly explains the disparity this way:

"Children who live below the poverty level are less likely to be vaccinated than children who live at or above the poverty level. Because a substantial percentage of black children lived below the poverty level, coverage for black children overall was low compared with white children. Therefore, even though the 2006 survey found that black, non-Hispanic children had lower vaccination rates than white, non-Hispanic children for the series of routine vaccines, at [sic] the difference was likely related to socioeconomic status and household income rather than race."

As for teenagers, the NIS-Teen data was not as encouraging, as none of the recommended vaccines for this age group had coverage levels meeting the Healthy People 2010 goals. The accompanying editorial note and CDC press release point to the relative newness of several of the new recommendations for teenagers. Both look to the data as evidence for continued education of parents and health care providers about the benefits of these vaccines.

Seasonal flu: Benefits of childhood vaccination; '06-'07 flu season wrap-up

Among the many vaccine-related contributions to the latest issue of Pediatrics (dated September 1) is a paper titled "Childhood Influenza: Number Needed to Vaccinate to Prevent 1 Hospitalization or Outpatient Visit." (free abstract; subscription required for full text). The authors seek to evaluate the potential benefit of influenza vaccination of children ages 6-59 months following the ACIP decision last year to add this group to those for whom the vaccine is recommended annually.

Determining the "number needed to treat" is a common tool of epidemiologists and those interested in the cost-effectiveness of medical treatments. The methods and results of this study don't lend themselves well to summary, but here is the authors' one-sentence conclusion:

"With 1 outpatient visit being prevented through vaccination of [fewer than] 50 children, influenza vaccination can reduce influenza-attributable medical visits in children significantly, even in years with modest vaccine efficacy."

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Speaking of influenza vaccination, a report in MMWR in mid-August wrapped up the 2006-07 flu season and previewed the vaccine composition for the upcoming 07-08 season.

The report notes that the 2006-07 season was comparatively mild relative to the 3 flu seasons that preceded it, as mortality and pediatric hospitality rates were all below those of recent year.

The influenza vaccine for the upcoming season will include two of the same strains in last year's vaccine, with FDA advisers opting to include one different influenza A component. (Each season's vaccine includes two influenza A and one influenza B components.

MMWR: Flu recommendations and polio eradication update

Several interesting items related to vaccination appear in today's issue of MMWR. Among them:

-- A revision to the ACIP document "Prevention and Control of Influenza," an expansive review of all aspects of seasonal flu vaccination guidance and related data. Notable in this updated version is additional encouragement aimed at promoting influenza vaccination of health care workers as well as information on the composition of the 2007-08 vaccine.

-- A report on worldwide progress toward polio eradication, as of May 2007. The number of polio-endemic countries remains at four (Pakistan, Afghanistan, Nigeria, and India) with the vast majority of the 1,997 cases reported in 2006 occurring in Nigeria (1,123) and India (676). Global vaccination coverage stands at 78%, a number that is well over 90% in the Americas but far lower in Nigeria (39%) and India (58%). Those interested in polio eradication should visit our previous posts about polio, which include several items discussing the merits and challenges associated with pursuing eradication.

2007 Pediatric & adolescent immunization schedules released

Yesterday, the American Academy of Pediatrics released the 2007 recommended immunization schedules for children, adolescents and catch-up immunization. (As always, the schedules are a joint production of the ACIP, AAP, and American Academy of Family Physicians, but it appears that the AAP website is first to release it publicly.) The new schedule includes, among other changes, the new recommendations for rotavirus and HPV vaccination, as announced in 2006.

The traditional one-page schedule covering all vaccine doses from birth to 18 years had grown increasingly complex and crowded in recent years, a multi-colored sea of bars, shaded boxes, dotted lines, abbreviations, and minuscule print. The chief solution to this problem is the expansion of the single-page schedule to three pages, one for birth-6 years, another for ages 7-18, and a third for catch-up immunization spacing. Many of the more confusing design elements from years past have been eliminated and the fine-print footnotes are now bullet points.

While this update is marked improvement over previous versions with respect to comprehensibility, most parents will still be far better served consulting their physician to understand clearly which vaccines are recommended for their children and when.

Update, 1/5/06 -- The latest issue of CDC's MMWR also announces the newly revised schedules.

From MMWR: childhood & 65+ vaccination rates, 2006-07 adult schedule, and Menactra safety update

A great deal of news on vaccines and vaccination efforts has appeared in recent issues of the CDC's Morbidity and Mortality Weekly Report. Here are some items of note:

• "Childhood Influenza Vaccination Coverage -- United States, 2004-05 Influenza Season" and "Influenza and Pneumococcal Vaccination Coverage Among Persons >65 Years -- United States, 2004-05." With flu cases starting (very slowly) to appear, these two pieces offer some data on the effectiveness of efforts to vaccinate two populations at higher risk of influenza-related complications. For children, the headline is that young children (19-35 months) had a substantially higher vaccination rate in the 04-05 season than for the previous year -- likely attributable to stronger ACIP recommendations. However, the overall percentage of fully vaccinated children in this age group was still very low (17.8%). For 65+ adults, the reverse phenomenon is true: both flu and pneumococcal vaccination rates are over 60%, but flu vaccination rates in 2005 were 4% lower than a year earlier. (The MMWR story notes that all of these numbers are well below the goal of 90% included in Healthy People 2010.)

• Better news can be found in this report, "Vaccination Coverage Among Children Entering School, 2005-2006 School Year." Compiling the latest data available, a editorial note accompanying the report explains, "More than half of reporting states indicate that they have already reached the Healthy People 2010 goal of >95% coverage for each of the vaccines recommended by the Advisory Committee on Immunization Practices (ACIP); the remaining states are making progress toward this goal."

• The 2006-2007 Recommended Adult Immunization Schedule, approved by the ACIP at their June meeting, has been published. Particularly because of efforts made at simplifying the schedule's design, the document is a great source for a general overview of recommended vaccinations in the 18+ population.

• One final item provides an update on reports of cases of Guillain-Barre Syndrome (GBS) among recipients of Menactra, Sanofi Pasteur's meningococcal vaccine. (We've written previously about this story in April.) A total of 17 cases have been reported with a suspected link to Menactra vaccination. As the report explains, analysis of these cases suggests a slightly increased risk of GBS among Menactra recipients, but the risk of meningococcus itself is among the reasons why no change in the current recommendation is being made at this time.
  

CDC report on 2005 infant vaccination coverage

The National Immunization Survey is an annual effort by the CDC to evaluate coverage rates in infant populations (19-35 months) across the country. The telephone survey has several limitations and many critics, but it remains the best available, most comprehensive source of data on the success of vaccination programs nationwide.

In this week's MMWR, the 2005 data and discussion has been published. The report doesn't lend itself well to summary here, but suffice it to say that it is an excellent starting point for those looking for data of the scope of U.S. vaccination efforts in infants.

Rotavirus vaccine recommendations published in MMWR

Back in February, the ACIP recommended Merck's rotavirus vaccine, RotaTeq, for universal administration to infants. While provisional recommendations were posted on the ACIP's website in May (as we discussed here), just yesterday did the recommendations become official upon their publication in MMWR. Here are the full recommendations.

The publication means a few things: 1) The process of insurance companies adding RotaTeq to their list of covered vaccines will likely accelerate over the coming months, and 2) professional groups and individual pediatricians will increasingly recommend vaccination to parents as it becomes a standard part of pediatric care.

CDC update on Midwest mumps outbreak

Yesterday, the MMWR website posted a dispatch with an update on the mumps outbreak in the Midwest followed by a discussion of possible causes.

Through 2 May, 2,597 cases have been reported, 57% of which coming from Iowa. Fortunately, no more than 25 hospitalizations can be attributed to mumps among these cases, with no deaths.

Among the possible causes for the outbreak discussed in an accompanying editorial note are: 1) the close quarters of college dormitories, 2) the absence of 2-dose MMR vaccination requirements for college attendance in 8 of the 11 states affected, 3) delayed recognition of mumps by younger physicians with limited exposure (so to speak) to it or physicians not initially suspecting mumps among vaccinated patients, both leading to more time for transmission to occur, and 4) the long-known fact that the vaccine is less than 100% effective at preventing disease.

CDC update on possible link between meningitis vaccine and Guillain-Barre Syndrome

Today's issue of the Morbidity and Mortality Weekly Report (MMWR -- the widely-read CDC infectious disease publication) includes an update on a series of cases of Guillain-Barre Syndrome among college-age students shortly after receiving meningococcal vaccine. Below are excerpts from the CDC summary of the report. The bottom line: It's unclear whether the vaccine is responsible for the GBS cases, further study is needed, and no changes for the time being regarding the recommendation status of the vaccine.

"In October 2005, a possible association between Guillain-Barré Syndrome (GBS) and receipt of meningococcal conjugate vaccine (MCV4)...was reported. GBS is a serious neurologic disorder involving inflammatory demyelination of the peripheral nerves. At the time of the first report, five confirmed cases of GBS after receipt of MCV4 had been reported to the Vaccine Adverse Events Reporting System (VAERS). During the 4 months since, three additional confirmed cases of GBS have been reported...

Because available evidence neither proves nor disproves a causal relation between MCV4 and GBS, further monitoring and studies are ongoing within VAERS and the Vaccine Safety Datalink (VSD). CDC continues to recommend use of MCV4 for persons for whom vaccination is indicated; the additional reported cases have not resulted in any change to that recommendation."