As flu season begins, the message from health care providers remains the same: Vaccination is the single best way to protect yourself and others from the potentially life-threatening illness.
“Flu vaccinations protect us, our patients and our communities,” said Richard Ellison, MD, professor of medicine in the Division of Infectious Diseases and Immunology. “Not everybody gets the flu but when one does it can be a very severe illness. If you haven’t had it before doesn’t mean you can’t get in the future.”
The U.S. Centers for Disease Control recommends annual influenza vaccination for everyone aged 6 months and older. A new vaccine is developed each year because, unlike many other pathogens, influenza viruses mutate and evolve continuously.
“United States flu experts meet early each spring and look at the available data about which flu viruses circulated both last year in the United States as well as those circulating in the Southern Hemisphere’s latest flu season, and then design a vaccine that should protect against the flu virus strains that are likely to spread in the next flu season” Dr. Ellison said. “There are two types of flu viruses—influenza A and influenza B—and the vaccine is designed to protect against two different types of influenza A, an H1 and an H3, that may circulate as well as two influenza B viruses that may circulate.”
Formulations licensed for this year are either quadrivalent, meaning they will provide protection against four different strains of influenza, two A strains and two B strains, or trivalent, providing protection against two A strains and one B strain. Available vaccines include a quadrivalent intranasal spray for those who can’t abide needles, including children, and several formulations given by injection: a standard quadrivalent formulation; a trivalent version for individuals aged 65 and over that is stronger against the three included strains; and a special quadrivalent formulation for the few individuals who have severe egg allergies.
Even when flu vaccines are not well matched to circulating strains of the virus and are less effective than they could be, they help prevent spread to others, especially infants 6 months and under and the minority of adults who can’t get a flu shot. If vaccinated individuals do come down with flu, their symptoms will be milder and the illness’s duration will be shorter thanks to the overall increased antibodies produced by the vaccine.
“There is evidence that getting the vaccine decreases absenteeism from work,” Ellison said. “While it may not completely prevent you from getting the flu, you tend to be less sick and miss fewer days due to illness.”
Vaccination is even more important for pregnant women, senior citizens and people with chronic illnesses, for whom the flu is far more dangerous than otherwise healthy individuals. The vaccine will not give an individual influenza. The mild symptoms that may occur briefly after vaccination are a reaction to the antibodies the vaccine stimulates, indicating that the vaccine is in fact doing its job, Ellison said.
“We need more vaccine awareness. It’s our job as health care providers to hammer on the message that vaccines offer immense benefits,” he said. “During my own medical career, several diseases have almost disappeared in the United States because of vaccines.” These include measles, mumps and infections due to Haemophilus influenzae B (a bacterium that is different from the influenza virus) that was a leading cause of bacterial meningitis in children. Unfortunately, measles, which was virtually eradicated in the United States, has had a resurgence due to the anti-vaccination movement.
Ellison points to the Centers for Disease Control as the best source for comprehensive, accurate and up-to-date information about influenza prevention and treatment.