Starting in 2011, PittVax became one of five U.S. Influenza Vaccine Effectiveness Network
sites that provide data and analysis needed for public health officials to make or adjust recommendations for vaccination, antiviral and other treatments. PittVax is directed by Richard K. Zimmerman, M.D., M.P.H., professor, and Tricia Nowalk, Ph.D., R.D., associate professor, both in Pitt School of Medicine’s Department of Family Medicine
“The information we collect and share is one of the primary data sources that the CDC uses in setting its vaccination policies and recommendations for clinicians treating patients in any given flu season,” said Dr. Zimmerman, also professor in the Pitt Graduate School of Public Health’s Department of Behavioral and Community Health Sciences
. “In past years, we’ve given the evidence needed to prompt earlier and more widespread use of flu antiviral drugs. This season, our work has led to the recommendation to discontinue nasal spray flu vaccine because it has not been effective at preventing type A flu.”
The Pittsburgh site collects data from hundreds of patients seen at UPMC outpatient facilities with symptoms of an acute respiratory infection who consent to participate. They are tested to determine if they have flu or another illness, such as RSV, or simply a cold. The researchers also confirm whether or not the participants were immunized against flu earlier in the season and conduct a follow-up survey on participants’ recovery.
In the past five years, PittVax participants had the highest follow-up survey completion rate of any of the other sites and higher enrollment rates than required, with well over the 1,100 necessary participants annually. The program is supported by ongoing outbreak surveillance at six UPMC sites, with more than 14,000 respiratory virus tests performed each flu season.
These data allow PittVax and the other sites to determine if the flu vaccine—which is designed to work against the three or four strains of flu that the World Health Organization
predicts most likely to be circulating when the flu vaccine is manufactured, months before flu season actually starts—is effective against whatever strains of flu ultimately circulate.
Last season, the flu vaccine was nearly 60 percent effective, which means that the chances someone vaccinated against flu would get sick with the virus were less than half the chances of illness in someone who didn’t get the flu vaccine. In the 2014-2015 season, the vaccine was only 23 percent effective, the lowest in nearly a decade, but still offered considerably more protection against flu than not being vaccinated. On average, the vaccine is about 50 to 60 percent effective.
Based on data collected from 2015 to 2016 by PittVax and other sites, the nasal spray flu vaccine often offered to children was found to be only 3 percent effective, and the CDC’s Advisory Committee on Immunization Practices
recommended it not be offered this season, instead recommending the traditional influenza vaccination with a needle for everyone six months and older.
In the event of a flu pandemic—when a new strain of flu to which people have little existing immunity emerges and spreads globally—PittVax will be prepared to collect respiratory samples and conduct studies estimating how many people are affected and how well antivirals or existing flu vaccines work against it.
New with this grant, PittVax also will be prepared to collect and provide data and analysis on the effectiveness of the RSV vaccine, which is expected to be offered to older adults within the next five years, if clinical trials go well.
In his decades as a physician and family medicine and public health scientist, Dr. Zimmerman unequivocally recommends the flu vaccine for everyone included in the CDC policy.
“I’m vaccinated, my wife’s vaccinated, the kids at home are vaccinated, and I tell all my patients who should be vaccinated to get it,” said Dr. Zimmerman. “It is the single best way to avoid getting and spreading the flu, which is a deadly illness.”
PittVax is funded by CDC grant 1U01IP001035.