In a race to stave off an unusually dangerous flu season, scientists at the University of Maryland and seven other universities in the U.S. will begin testing a swine flu vaccine in adults and children within the next few weeks - the first step in what could be a mass vaccination campaign.
The trials, which will test the vaccines of two manufacturers, mark the launch of an aggressive government timetable to have inoculations ready for as many as 200 million Americans, including 2 million Marylanders, by mid-October. While there are unanswered questions about the campaign - from the logistics and cost to whether the vaccine will protect everyone from the virus - researchers expect to determine the vaccine's safety and effectiveness within six weeks of starting the trials.
Public health officials and infectious disease experts fear the virus, known as H1N1, could mutate into a nastier strain this fall. With that in mind, vulnerable groups - children, people who work with children, pregnant women, health care workers and adults with chronic diseases - are likely to be first in line for the vaccine. But first, scientists must determine whether it's safe, if it works and if not, what should be their next steps.
"What we are trying to do is to be prepared in case the infections come back with a vengeance," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, which is funding the trials. "The concern is that we will see a lot of infection, serious illness and maybe some deaths as kids go back to school. So we are going to try as best we can to get as much information about whether we are going to vaccinate on Oct. 15 and beyond. Doing these trials is our best effort to get as much information as we can."
Researchers nationwide will enroll about 2,400 volunteers in trials that will test two vaccines in five population groups. They will also study the best time to give the vaccine: before, during or after the typical vaccination schedule for the seasonal flu.
Scientists at the University of Maryland School of Medicine expect to receive a vaccine from manufacturer Sanofi Pasteur as soon as Aug. 10 and begin testing immediately on roughly 1,000 volunteers - adults at University of Maryland Medical Center and later on children at sites in Frederick and Annapolis.
The other vaccine, by Australian drug maker CSL, will be tested at another U.S. site, and testing is under way in Australia, said Dr. Karen L. Kotloff, professor of pediatrics and medicine at the University of Maryland's Center for Vaccine Development, and the principal investigator for the trial here.
Volunteers will receive two doses of the vaccine, three weeks apart and at two strengths. Healthy adults and the elderly will be tested before the vaccine is tried in children as young as 6 months old. Children have been more susceptible to the new H1N1 strain. Medical experts think that older people may have been exposed to similar strains of the virus and may have some immune protection against it.
Health officials, infectious disease experts and vaccine makers have been scrambling for months to confront the swine flu pandemic, which has killed at least 263 people nationwide since its outbreak this spring - including three in Maryland - and sickened as many as 1 million, according to estimates by the Centers for Disease Control and Prevention. Most cases have been mild, however, and people who fall ill with flulike symptoms usually recover with in a week or so, much like the seasonal flu.
Still, public health officials have been monitoring the virus' spread in the Southern Hemisphere, where flu season is now at its peak, paying close attention to any changes in the strain.
Kotloff acknowledged that researchers are rushing to provide as much information as they can, but that despite the short timetable, they are taking clues from seasonal flu vaccine. Seasonal flu kills 36,000 in the U.S. each year and hospitalizes hundreds of thousands.
"Every year there's a race against time," she said. "At the beginning of the calendar year, authorities need to make a decision which strains they think will circulate in the autumn, and then the vaccine makers have to race to make sure the vaccine is available to the public."
But there are key differences between this effort and the seasonal flu vaccine process. Vaccine makers didn't get hold of the swine flu virus until this spring and seasonal flu vaccines are not tested on people before they are rolled out for flu season.
"This is different because we have never seen it before," said Fauci. "It behooves us, before the fact, to get some safety data. In many respects this is very similar to a seasonal vaccine that we give on a yearly basis. But, because of an abundance of caution, we are going to do clinical trials before we make that decision to vaccinate."