Preventing and controlling influenza - February SNHD Update

by Dr. Joseph Iser  Chief Health Officer, SNHD  Member Since 2013

by Dr. Joseph Iser

Chief Health Officer, SNHD

Member Since 2013

Preventing and controlling influenza

After the first of the year, flu activity increased throughout most of the United States and reports questioning the effectiveness of this year’s flu vaccine were widespread in the media. Many of these reports were based on Australia’s interim estimate of the vaccine’s benefit against one flu virus (H3N2) that circulated during past flu seasons. Because vaccine effectiveness cannot be accurately predicted during a current season, it is too soon to evaluate this year’s match to the strains of flu currently circulating. However, last season’s vaccine effectiveness in the United States was estimated at 39 percent, and the effectiveness against H3N2 viruses was only slightly lower at 32 percent. The Centers for Disease Control and Prevention (CDC) believes that these estimates are better at forecasting the flu vaccine benefits for the United States. This is assuming there are minimal changes to the current viruses that are circulating. 

Influenza viruses change each year . . . . Current recommended vaccines protect against three or four of the circulating strains . . . . People 65 years and older should get the high-dose flu vaccine . . . . Flu mist is no longer recommended . . . . The flu shot may not be as effective – but you should still get it.
— Centers for Disease Control

With so many competing, and to the public what can seem like contradictory messages, health care providers must be consistent advocates for flu vaccinations. When the public hears the vaccine may not be as effective or the percentages associated with vaccine effectiveness, it may skew their perception of the benefits. There are overarching messages that our patients should hear on a continuing basis to reinforce the importance of being vaccinated every year against the flu. 

These include:

  • The flu shot won’t make you sick. 
  • While flu vaccine effectiveness may vary, it is the best way to prevent flu illness and serious complications from the flu, including those that result in hospitalization. 
  • Even when vaccine effectiveness is in the range of 30 to 60 percent, flu vaccination prevents millions of illnesses each year and tens of thousands of flu-related hospitalizations each year. 
  • While the vaccine is not perfect and some people who get vaccinated may still get the flu, there is research that suggests that people who get the flu vaccine will have milder illness. 
  • Getting vaccinated protects people around you. This includes those more vulnerable to developing serious illness, such as babies, young children, the elderly, and people with certain chronic health conditions. 

While the flu vaccine is the first line of defense, antiviral drugs can be effective to treat flu illness. The CDC recommends that people who are very sick or people who are at high risk of serious complications from flu illness be treated early with flu antiviral medications. Because there can be spot shortages of these drugs, they should be reserved for those most in need during peak flu season. Treatment with an antiviral drug can mean the difference between having a milder illness or a hospital stay for an at-risk patient. Most healthy people do not warrant treatment with flu antiviral drugs unless their health care provider determines there is a need based on the severity of their illness. 

We must also be tireless advocates for vaccine research. Cell-grown reference viruses may offer the potential to provide better protection than egg-based flu vaccines. It is also imperative that better and more rapid production methods of vaccine are developed, as well as a universal flu vaccine. A universal vaccine could not only offer years of protection against many different strains of the flu, it is also vital to our public health preparedness efforts. The threat of an outbreak of a pandemic flu is very real. The toll could be unthinkable if a virulent strain were to strike and it took months to manufacture a vaccine.