First H1N1 vaccine trial data expected in mid-September
Robert Roos 
News Editor
Aug 21, 2009 (CIDRAP News) – Federal health officials todaysaid the first results of novel H1N1 vaccine trials—needed for determining thenumber and size of doses people will get—are expected in mid-September.
Two trials in adult and elderly volunteers started Aug 7 andare now almost fully enrolled, said Dr. Anthony Fauci, director of the NationalInstitute of Allergy and Infectious Diseases (NIAID), at a pressteleconference.
"We expect first-dose data somewhere aroundmid-September, if all goes well . . . and second-dose data somewhere aroundmid-October," he said.
The trials will help determine the dose size—15 versus 30micrograms (mcg)—and whether each person will need one or two doses to get agood immune response.
Federal officials have been saying two doses will probablybe necessary, because most people lack any immunity to the novel virus. But nodecision has been made yet, and today officials said it will depend on theearly results of the trials. A recommendation for two doses will slash theeffective vaccine supply and complicate vaccination planning for the fall, asmillions of people will need a dose of seasonal flu vaccine plus two doses ofthe novel H1N1 vaccine.
Responding to a question, Dr. Jesse Goodman, acting chiefscientist and deputy commissioner of the Food and Drug Administration (FDA),noted that young children typically require two doses of inactivated fluvaccine.
For adults, he said, "We will not know until we see theresults of the clinical studies whether . . . older individuals will also needtwo doses. I think we all feel that this is a distinct possibility that we needto be prepared for, but it's also possible that they will have enough cumulativeimmunity to other H1N1 strains that we may see an effect after one dose."
Fauci added, "You just really have to stay tuned. . . .We're going to know as we get into mid to late September whether or not we havea pretty good response to that first dose of 15 or 30 [mcg]."
This week the NIAID announced the start of two H1N1 vaccinetrials in children aged 6 months to 17 years, after the early experience in theadult trials showed no immediate safety problems. Fauci said the children's trials,involving about 2,800 subjects, are expected to yield first-dose data in lateSeptember and second-dose data in late October.
He also announced plans to conduct three trials involvingpregnant women, testing one or two doses of 15 or 30 mcg, with about 120 women ineach trial. The tests are scheduled to start in early September.
In addition, trials in which different adjuvants will bematched with multiple vaccines will start in late September, Fauci reported.Goodman reiterated today that no decisions have been made about adjuvant use.
Fauci said the NIAID-sponsored trials will involve about4,500 volunteers in all.
In other comments at the press conference, Dr. Jay Butler ofthe Centers for Disease Control and Prevention (CDC) slightly revised the recentlyreduced forecast for the early supply of H1N1 vaccine. At a meeting a week ago,a Department of Health and Human Services official downsized the forecast ofwhat will be available in mid October from the previous 120 million doses to 45million doses.
Butler said today, "We're expecting somewhere between45 million and 52 million doses to be available by mid October. This will befollowed by weekly availability of vaccine up to about 195 million doses by theend of the year."
In other observations, Butler released the CDC's latestsurveillance data, showing that the nation has had 7,963 hospital cases ofnovel H1N1 flu and 522 deaths so far. He said 75% of the hospital cases and 60%of deaths involved people under age 49.
H1N1 activity appears to be declining in the southernhemisphere, and the epidemiology of the disease there is very similar to whatwas seen in the United States this past spring, he reported. No significantchanges in the virus have been detected in the southern regions.
Today the CDC published the full-length version of theAdvisory Committee on Immunization Practices' recommendations on use of novelH1N1 vaccines. The recommendations on target groups for vaccination and relatedissues were first made public on Jul 29. The detailed version appears as an MMWRDispatch.
See also:
Jul 22 story CIDRAP News story on NIAID-sponsored clinicaltrials
http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/news/jul2209trials.html
Jul 22 NIAID news release on H1N1 vaccine clinical trials
http://www.niaid.nih.gov/news/newsreleases/2009/Pages/VTEU_H1N1.aspx
NIAID questions and answers on pediatric vaccine trials
http://www.niaid.nih.gov/news/QA/Pages/qaH1N1pedvax.aspx
MMWR Dispatch on useof H1N1 vaccine
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr58e0821a1.htm?s_cid=rr58e0821a1_e
