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.

Updates: HIV vaccine reassessment; 2nd rotavirus vaccine approved; Avian flu vaccine supply

Here are a few updates on topics we've been covering over the past several months:

• HIV vaccine research -- Several months after the failure of what was billed as the 'most promising' HIV vaccine candidate, NIAID organized a meeting late last month to reassess the state of HIV vaccine research and plans for the future. The "Summit on HIV Vaccine Research and Development" garnered significant media attention from the Washington Post and New York Times, among other outlets. The apparent take-away message from the meeting was that renewed effort must be directed toward basic research and novel ideas. A subsequent Times editorial argued that the potential benefit of a vaccine is too great to give up hope. A webcast of the meeting is available at the NIAID summit website.

• Rotavirus vaccines -- As expected, on Thursday, FDA approved GSK's Rotarix, now the second rotavirus vaccine available in the United States. Here's a story from the Associated Press, the FDA press release and the GSK release. The major difference between Rotarix and Merck's RotaTeq is that Rotarix requires two doses compared to three for RotaTeq. No word yet on the price of Rotarix, which had already been licensed in over 100 countries. It is expected to be available in the U.S. later this year.
  

• Pandemic flu planning -- Another update on the federal government's pandemic flu planning was released by HHS Secretary Michael Leavitt late last month. Updates on vaccine development and stockpiling figure prominently in the report. It notes that enough pre-pandemic vaccine for 13 million people was stockpiled by the end of 2007. This CIDRAP News story has more details.

FDA: GSK rotavirus vaccine appears safe and effective

Rotarix, the rotavirus vaccine developed by GSK, moved closer to U.S. licensure on Friday, as an FDA staff report stated that clinical trial results suggest that the vaccine is safe and effective.

Here is coverage of the news from The Wall Street Journal, Associated Press and Dow Jones. Rates of intussusception -- the gastrointestinal condition that doomed the first rotavirus vaccine, Rotashield, in 1999 -- were not significantly different in those receiving Rotarix versus control groups receiving a placebo.

A positive recommendation from government advisors at next week's meeting of FDA's Vaccines and Related Biological Products Advisory Committee would likely be the final step prior to licensure in the U.S. Rotarix is already approved in over 90 countries, according to GSK.

Merck's rotavirus vaccine, RotaTeq, was approved in February 2006 and is currently recommended for all infants at 2, 4, and 6 months of age

From Pediatrics: GSK rotavirus trials; trial of school-based flu vaccine program

In a slow midsummer period for vaccine news, two papers appearing in the journal Pediatrics this month deserve mention:

• "Dose Response and Efficacy of a Live, Attenuated Human Rotavirus Vaccine in Mexican Infants" -- This is a report on a trial of GSK's rotavirus vaccine, Rotarix. The study of 405 infants showed the vaccine to be safe and effective. Rotarix is still awaiting U.S. licensure -- the application was filed late last month, according to this announcement -- but it is already available around the world (including the EU, as this 2006 press release announced). With Merck's rotavirus vaccine, RotaTeq, available in the U.S. since 2006, another Merck-GSK head-to-head showdown is bound to occur, albeit one certain to be far less noticeable than the imminent competition for the HPV vaccine market likely to begin in 2008.

• "Mass Distribution of Free, Intranasally Administered Influenza Vaccine in a Public School System" -- The paper reports on a school-based influenza vaccination program in the Knoxville, TN area. Roughly 24,000 of 53,000 students received the FluMist vaccine, an encouraging number according to the study's authors. Of concern, however, was the amount of resources (notably, 6900 person-hours of labor) needed to execute the program. The program described here was funded in part by MedImmune (since purchased by AstraZeneca), the manufacturer of FluMist. Nevertheless, the paper's authors are correct to note the value of trials such as this in evaluating the feasibility of school-based programs to increase pediatric vaccination rates or as part of pandemic response efforts.