For the past four years Baylor Scott & White Health–Temple has participated in a study looking at Hospitalized Adult Influenza Vaccine Effectiveness Network study.
On Tuesday, Jill Ferdinands, lead investigator for the Centers of Disease Control and Prevention study, along with Brendan Flannery, epidemiologist with the CDC, were in Temple at Baylor Scott & White Health for the annual investigators meeting for hospitalized flu vaccines.
Dr. Manjusha Gaglani, pediatric infectious disease physician at Baylor Scott & White McLane Children’s Medical Center, is principal investigator in Temple for the CDC US Flu Vaccine Effectiveness Network study, an annual outpatient study.
Other medical centers participating in the hospitalized flu vaccine study include University of Michigan, University of Pittsburgh, Vanderbilt University and Baylor Scott & White Health.
The primary goal of the hospitalized flu vaccine study is to determine the effectiveness of the vaccine, Ferdinands said. However, the inpatient studies also look at prevention of hospitalizations.
There is another study at the CDC that looks at hospitalized children, she said.
There are typically 2,000 to 4,000 patients enrolled in the hospitalized flu vaccine study, depending on the flu season.
“This past year it was closer to 4,000,” Ferdinands said. “We get 1,000 to 1,200 from Baylor Scott & White.”
Those medical centers and their patients enrolled in the hospitalized flu vaccine study play a big role in helping researchers understand how the vaccines work.
Area participants are patients at Baylor Scott & White in Temple, Round Rock and Waco Hillcrest, Gaglani said.
The outpatient study is for adults and children and it looks at medical visits and if the visit was related to a flu diagnosis.
The inpatient study has many more adult patients over the age of 65 who have more health conditions, she said.
“It’s a sicker population than those in the outpatient study,” Gaglani said.
The sicker population is more of a challenge when it comes to judging the effectiveness of the vaccine, Ferdinands said. The average age of individuals in the hospitalized flu vaccine study is 63 to 64 years old.
The normal hospital stay for an adult with the flu is about four days and about 25 percent of those individuals will require intensive care.
“We collect and use more information about the patient’s health status before they are hospitalized,” she said.
In the 2018-2019 flu season, the vaccine had a 30 percent effective rate in preventing outpatient visits and hospitalizations. The previous season had similar vaccine outcomes.
“The surprise this season was that we saw two types of influenza circulating,” Flannery said. “There’s usually one dominant strain.”
Protection was good for the H1N1 virus that hadn’t circulated for a few years, and poor protection against the new H3N2 virus, he said.
The H3N2 virus began to circulate in the midst of the season and the vaccine strain wasn’t a good match, Flannery said. The World Health Organization has chosen the H3N2 strain to be included in the vaccine for the coming season.
The introduction of the H3N2 virus in 2019 showed up in Texas before it hit other research sites involved in the study.
“It gave us a first look at the flu virus that we’d never seen before,” Ferdinands said
The flu virus is adept at mutating and it does so quickly, so it’s important to reformulate the vaccine each year, she said.
Those who get the new vaccine each year, cut the probability of having to see their doctor because of flu by 50 percent, Gaglani said.
Flu does kill, more than 30,000 Americans die of the flu every season, she said. There are people in the community who are immunocompromised or have lung conditions who should not be exposed to the flu.
“We study flu vaccine in clinics to understand how well the vaccine prevents against the regular flu,” Flannery said. “The importance of this study is to look at vaccines in hospitals because we want to make sure that the vaccine prevents severe disease.”