TUESDAY, July 28, 2009 (HealthDay News) -- With the first trials of a vaccine against the new H1N1 swine flu set to begin shortly, the U.S. Centers for Disease Control and Prevention will convene a panel of experts Wednesday to recommend a priority list of candidates for the vaccine.
Those recommendations will assume that a safe and effective vaccine will be available by October in sufficient quantity to start a mass vaccination program in the United States. If all goes well, the safety and effectiveness of the vaccine should be known by late August or September, federal officials said.
"The panel will get an update on the H1N1 in the United States," said CDC spokesman Tom Skinner. "They will get an update on where things stand with the development of a vaccine against novel H1N1 and an update on the steps being taken to plan for a potential vaccination campaign in the fall."
By meeting's end, the CDC expects to have a good idea of who should be given priority for the vaccine, Skinner said.
"We won't have final guidelines for use of the vaccine, [but] we will have a pretty good idea of who is going to be first in line to get a vaccine if we get to the point of having a vaccine that is safe and effective by late fall or early winter," he said.
The CDC's Advisory Committee on Immunization Practices will consider various scenarios, including a vaccine shortage, Skinner said. And once a vaccine has been approved, the panel will vote on final recommendations for its use, he said.
Dr. Marc Siegel, an associate professor of medicine at New York University Langone Medical Center in New York City, thinks he has a pretty good idea of what the recommendation for the H1N1 vaccine will be.
"We should target health-care workers, those under 2 [years of age], pregnant women, those chronically ill, those with asthma," Siegel said. "The next category should be school children. Not only is schools where flu spreads, but there isn't as much immunity in the younger population."
All these groups have been the most susceptible to the H1N1 swine flu, with the majority of hospitalizations and deaths. Unlike seasonal flu, which typically strikes hardest at the very young and the elderly, H1N1 swine flu has proven more troublesome for children and young adults. Scientists believe that older people might have some immunity to H1N1 viruses, which haven't been predominant flu strains for several decades.
Another infectious-disease expert said the twin threats of seasonal flu and the new H1N1 strain will require many people to get shots for both diseases and could pose management problems.
"This coming flu season will be quite different than those in the recent past as the new H1N1 swine flu strain will in all probability re-emerge and cause significant illness in at-risk people, such as young children and adolescents," said Dr. Pascal James Imperato, dean and distinguished service professor in the School of Public Health at SUNY Downstate Medical Center in New York City.
The seasonal flu vaccine will offer no protection against the H1N1 swine flu, he said.
"This means that some groups in the population will need to receive more than just one flu shot in order to be protected against all of the influenza strains in circulation," Imperato said. "This is an unusual circumstance and will require additional documentation effort on the part of those administering the flu vaccines and people receiving them to be sure that the appropriate immunizations are given."
"There may also be logistical challenges for patients and health-care providers as we attempt to deliver two different influenza vaccines during the same season," he added.
Then there's the lingering memory of the 1976 swine flu vaccination program, during which some 500 Americans came down with a rare neurodegenerative condition called Guillain-Barre syndrome, which many experts believe was linked to the shot. Twenty-five of those 500 people died.
"The potential for more severe illness and many more deaths caused by this new strain of influenza weighs heavily on our minds -- as does the unfortunate outcome of the 1976 swine flu vaccination program," said CDC spokeswoman Arleen Porcell-Pharr.
The H1N1 flu vaccines will be very much like seasonal flu vaccines, which have an excellent safety profile, Porcell-Pharr said. "However, no vaccine is 100 percent safe. This vaccine will be no exception," she said.
If the vaccines are recommended for use, those who choose to be inoculated will receive information sheets describing the vaccines' risks and benefits, signs of side effects to look for after vaccination, and information on how to report adverse events, she added.
"We will be watching very closely for any signs that the vaccine is causing unexpected side effects, and we have systems in place to investigate those signals rapidly," Porcell-Pharr said.
The U.S. Centers for Disease Control and Prevention have more on H1N1 swine flu.