Mutation in strains make flu a moving target

That number can rise or fall – often dramatically – based on the effectiveness of the selected flu vaccine, said Dr. Jorge Parada, director of infection prevention and control at Loyola University Health System.

The newly approved 2011-12 flu vaccine is exactly the same as that of last winter and again will target the H1N1, Perth and Brisbane flu viruses.

“Southeast Asia experiences the flu first and then it is spread globally,” Dr. Parada said. “A panel of influenza experts examines what is happening there and bases the flu vaccine on what they are seeing to prevent and attenuate the disease.”

Dr. Parada said last year’s vaccine was effective. “The prediction was right on,” he said. “And even though the vaccine is the same this year, people will still need to get a new vaccination.”

The flu vaccination is usually good for six months of prevention.

Triple Threat of Catching Three Varieties of Flu

People can potentially catch the flu three times in one season. “There are two species of influenza that typically infect humans, Influenza A and Influenza B,” Dr. Parada said. “And there are two strains of Influenza A, one of which is commonly called the Swine Flu.”

Unlike measles, which you get once and never get again, people can get sick from different strains of the flu over and over. “The flu virus is not stable and mutates, creating new varieties of the flu,” Dr. Parada said.

Flu Season Unpredictable

The traditional flu season lasts from December to February, with January and February being peak months. Because the flu season can vary, Dr. Parada advised getting the vaccine as early as possible. “The 2009-10 season was an anomaly because the flu presented early and peaked in Chicago in mid- October through mid-November,” he said.

Because of the potential for an early season, Dr. Parada said the Loyola medical community will offer the vaccination in late summer. Gottlieb Memorial Hospital, part of Loyola University Health System, will start providing flu vaccinations Sept. 1. “In addition to thwarting an early season, the flu vaccination takes two weeks to build immunity, so the earlier you receive it, the better chance you have of flu prevention.”

Dr. Parada said Loyola has a unique culture of safety and “walks the talk” when it comes to the flu. “This is the third year in a row that flu vaccinations are mandatory for staff, vendors, students and volunteers,” he said. “Loyola had more than 99 percent compliance for the flu vaccine last year, netting a double risk reduction and a win-win . Staffers were protected from getting infected by patients, and patients were protected from the spread of infection from medical staff.”

Provided by Loyola University Health System