BY SRILATHA EDUPUGANTI, MD, MPH
Assistant professor of medicine in the Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine; Medical director of the Hope Clinic of the Emory Vaccine Center; investigator in the adult H1N1 influenza clinical trials.
With the arrival of fall, and schools and colleges well under way, Georgia already has seen a substantial number of cases of novel H1N1 flu. Although it appears that most cases have been mild, there have been more serious cases, just as there are every year with seasonal flu.
Doctors in the region have noted serious illness not only among individuals with underlying medical conditions but also among young, previously healthy individuals.
The U.S. government declared the H1N1 outbreak a public health emergency in April 2009, and two months later the World Health Organization classified the outbreak a pandemic, reflecting its widespread nature. To minimize the impact of H1N1 flu in our community, public health experts have been providing information on prevention and management to the public and health care providers.
Clinical trials testing H1N1 vaccines in adults and children have been under way since August at Emory and a few other academic medical centers around the nation. The H1N1 flu vaccine clinical trials were designed to answer three key questions:
Participants in one Emory adult and senior study received a total of two H1N1 vaccinations, either concurrent with, before, or after, the seasonal flu shot. Participants in the Emory and Children’s Healthcare of Atlanta pediatric trial also received a total of two H1N1 shots, and one seasonal flu shot. Another adult and senior study (currently enrolling) is evaluating the safety, tolerance and immune responses with an adjuvanted H1N1 vaccine. The adjuvanted vaccine contains an extra “helper” material (an oil-in-water emulsion) mixed with H1N1 vaccine that may strengthen the immune response to the vaccine.
The trials have been conducted in a compressed timeframe so that the government could quickly make recommendations for the vaccines. Early data already have shown the unadjuvanted vaccines to be safe and well tolerated. Recently, the Food and Drug Administration approved four companies’ vaccines, which will be distributed as soon as they are available, most likely in mid to late October. The nasal spray H1N1 flu vaccine is expected be available in early October. The adjuvanted H1N1 vaccine trial has just begun so those safety and immunogenicity data are pending.
The clinical trials will continue for the next several weeks and will help experts continue to make decisions about how the vaccines should be used. Initial immune response data show only one dose will be needed for healthy adults and children 10 and older, but the Centers for Disease Control and Prevention (CDC) will make specific recommendations when the vaccines are distributed.
The CDC already has recommended certain high priority groups for H1N1 vaccination when it becomes available. In making its recommendations, the group considered current disease patterns and current trends that showed populations most at risk of serious illness, among other factors.
The CDC reports that it does not expect a shortage of 2009 H1N1 vaccine, but availability and demand can be unpredictable. There is some possibility that initially the vaccine will be available in limited quantities.
It is recommended that the following groups receive the vaccine before others: pregnant women, people who live with or care for children younger than 6 months of age, health care and emergency medical services personnel with direct patient contact, all people from 6 months through 24 years of age, and people aged 25 through 64 years who have health conditions associated with higher risk of medical complications from flu.
Once these priority groups have received vaccinations, everyone from ages 25 through 64 should get the vaccine, followed by those over age 65.
It is important to remember that the seasonal flu vaccine will not protect against the H1N1 flu. Receiving both vaccines this fall will be key in keeping you and your family healthy. The vaccines can be given on the same day in separate shots, but flu experts are asking that individuals, particularly those over age 65, go ahead and get a seasonal vaccine now, if possible.
For more information about the H1N1 flu vaccine trials at Emory, call 877-424-HOPE (4673) or visit http://www.medicine.emory.edu/id/hopeclinic for adult trials; or 404-727-4044 for the pediatric trials.