Why not everything you hear about the flu is true

This year’s flu season caught public health officials off guard. They did not anticipate such widespread outbreaks would stretch emergency rooms beyond their limits.

Vaccine makers thought this year’s flu shot would protect people from infection. They didn’t count on the dominant strain of flu, H3N2, mutating.

As a result, this year’s vaccine doesn’t seem to be very effective. Early warning signals from Australia should have alerted U.S. experts that we could be in for trouble. The flu season in the Southern Hemisphere runs about six months ahead of ours. In Australia, the vaccine was only about 10 percent effective against H3N2, which caused most of the serious flu cases there (New England Journal of Medicine, Jan. 4, 2018).

Now, evidence from Canada shows a similar situation in North America. Preliminary reports indicate that the flu vaccine is about 10 percent effective against H3N2 in adults under 65 (Eurosurveillance, February 2018).

Despite this disappointing performance, public health officials still urge everyone to get a flu shot. Their rationale is that the vaccination will lessen the severity of the illness even if it won’t prevent infection.

How strong is the evidence? French investigators have expressed surprise that there has been so little high-quality research on this question (Vaccine, April 11, 2017).

The researchers wanted to know if a flu shot would result in less severe illness such as pneumonia or hospitalization. The study that they conducted on 2,277 French seniors found that three-fourths of the seniors who tested positive for influenza had been immunized. Those who had received the shot were less likely to suffer headaches from the flu. This small benefit led the scientists to conclude, “Our results are consistent with previous studies reporting limited or no efficacy of the influenza vaccine in reducing illness severity at onset of symptoms.” They call for influenza vaccines to provide better protection.

The other advice that public health officials always give at this time of year is that hand-washing is critical. Washing your hands is a good practice anytime, but just how well does it protect people against influenza? This question is hard to study, but some scientists have tackled it. A review of the research found that a combination of hand-washing and face masks provided statistically significant protection against influenza (Epidemiology and Infection, May 2014). Hand hygiene alone was not effective. The authors conclude, “The modest efficacy of hand hygiene suggests that additional measures besides hand hygiene may also be important to control influenza.”

Research from Hong Kong demonstrates that face masks together with hand-washing helps prevent household transmission of flu (Annals of Internal Medicine, Oct. 6, 2009).

Americans don’t generally embrace face masks the way people in China or Japan appear to. There haven’t been public health messages in the U.S. endorsing face masks. But new research suggests that there should be.

A person with the flu doesn’t have to cough or sneeze to spread viruses. Researchers at the University of Maryland discovered that simply breathing puts virus-containing droplets into the air (Proceedings of the National Academy of Sciences, January 2018). The lead author suggests, “So when someone is coming down with influenza, they should go home and not remain in the workplace and infect others.”

Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email them via their website: www.PeoplesPharmacy.com.

2018 King Features Syndicate