Flu Season is Upon Us!
Last updated: September 2021
For those of us in the northern hemisphere, we have officially entered influenza season. Most of us understand the importance of the flu shot for the elderly, children, and those who are immunocompromised. At times, the importance of the influenza vaccine in people with hepatitis C may be overlooked. Studies confirm this: Only 55% of people with chronic liver disease received their flu shot in 2016.1
Background on the influenza virus
Influenza is a contagious respiratory illness caused mainly by influenza A and/or B viruses. Unlike the hepatitis virus, influenza is acute; that is, the flu does not cause long-term infection. Influenza usually spreads during the winter season in temperate climates. Symptoms may include a fever, cough, sore throat, runny nose, muscle aches, fatigue, and headaches. Most people are able to recover from the flu in less than 2 weeks.
Influenza and COVID-19
This year, there is a greater emphasis on the uptake of the influenza vaccine because of it's overlap with the COVID-19 pandemic. The flu shot will not prevent COVID-19. However, influenza and COVID-19 share similar symptoms, making it tricky for clinicians to diagnose based on symptoms alone. The only way to confirm the diagnosis would be to test for each virus, which can place a strain on our health resources.
Flu vaccine in people with chronic hepatitis C infection
A common concern is whether the flu vaccine is as effective in people with hepatitis C as it is in people with no chronic conditions. Results from a trial show that those with hepatitis C and vaccinated against the flu were 27% less likely to be admitted to the hospital than those with hepatitis C and unvaccinated. Overall, people with liver disease have a 5-fold increased risk of hospitalization related to influenza, and a 17-fold increased risk of death compared to those with no liver disease.2
Autoimmune hepatitis (AIH) occurs when the immune system attacks the liver cells, resulting in inflammation and liver damage. It presents as acute hepatitis, similar to hepatitis C, and then can progress to chronic hepatitis and cirrhosis. AIH is usually caused by an environmental trigger; For example, some of these cases develop after vaccine administration. One of the vaccines possibly linked to AIH is the influenza vaccine. The condition is so rare that to date, only 2 people have developed AIH after receiving the flu shot in the United States.3 Fear of AIH should not be a reason for deferring influenza vaccination in people with viral hepatitis.
Who should not receive the flu vaccine
There are some cases where people should not receive the flu shot. People who have had a severe allergic reaction to a prior flu shot (i.e. anaphylaxis), should not re-attempt unless medically supervised with an allergist. People who developed Guillain-Barré syndrome within 6 weeks of previous vaccination should also not receive another flu shot.
If you've never received the flu shot, this is the year to start! Speak to your physician, nurse and/or pharmacist about your concerns and eligibility for the vaccine.
Let us know your plan for getting a flu shot below!