Dr. Allison McGeer in workspace

Dr. Allison McGeer, Medical Director of Infection Prevention and Control at Sinai Health System

Dr. Allison McGeer, Sinai Health System’s Medical Director of Infection Control is routinely asked to assist in containing dangerous infectious diseases in regions around the world. She was on the front lines during Toronto’s SARS crisis and has worked with the World Health Organization (WHO) on MERS coronavirus and Ebola containment strategies.

Here at home Allison treats influenza with as much gravity as any other infectious disease—you may have even seen her giving flu shots in the lobby clinic this week at Mount Sinai Hospital. In this Q&A Allison talks about why the flu is a big deal, whether we can predict how bad flu season will be, and the possibility of a flu shot that lasts for years instead of months.

Q: At this time of year people start seeing ads in their pharmacies about flu shots. Some people are maybe wishing they had a crystal ball to know whether it will be a bad flu season this year. Is there any way to predict or any signs to indicate that flu season may be bad this year?

Dr. Allison McGeer (AM): Unfortunately, there is no means of predicting what kind of season it is going to be until activity starts, usually in mid or late November. But it is only about once in every 10 years that there is very little influenza activity, so for most people it makes more sense just to get your influenza vaccine every year.

Ultimately, as healthcare providers, we know it’s important to be prepared for anything. It’s the same thing with flu season. The flu shot is the best form of protection we have. It’s safe. It’s recommended for all healthy children and adults over six months of age and it’s free.

Q: Why do we have to get the flu shot every year? Will there ever be a vaccine that will provide longer-lasting protection?
Currently, influenza vaccines target a protein on the surface of influenza viruses called hemagglutinin. These proteins are essential in allowing the virus to invade our cells. Antibodies to hemagglutinin are what protect us best against influenza. However, this part of the influenza virus changes very quickly, such that new vaccines need to be made every year to protect us from influenza viruses with hemagglutinin that has changed.

Scientists are working hard at creating a “universal” influenza vaccine that will protect against all strains of influenza and last for many years. This type of vaccine has now been developed for mice, and there is good reason to hope that this type of vaccine will be in clinical trials within the next few years.

Q: Every year there’s a lot of effort put in to preventing an illness that a lot of people think of as being similar to the common cold. Why is influenza a big deal?

AM: People don’t realize just how life-threatening influenza can be.  It’s highly contagious and it can lead to serious complications and death, especially in the elderly, young children, those who are pregnant as well as people with health conditions such as asthma, diabetes, cancer, heart disease and lung disease. We all know people who are at high risk of complications from the flu and we come into contact with them every day.

Q: We know which groups are at greatest risk of becoming seriously ill, why not target flu shot campaigns to the more vulnerable people so that they’re protected?

AM: The most important is that most people who are at greater risk of serious illness don’t have robust immune systems, and the protection they get from the flu shot is not as robust either. It’s still important for them to get the flu shot, but this is where the concept of herd immunity comes in. When healthy people get the flu shot, they are protected against influenza, and can’t pass influenza on to their more vulnerable contacts. The more people who get vaccinated, the fewer chances there are for the virus to spread through our communities or our hospital.

Q: What about people who say, ‘I’m healthy, I never get sick and I’m making sure I clean my hands often so given the risk of side effects from the vaccine, it’s not worth it for me to get the flu shot.’ What do you say to those people?

AM: This is a very common way of thinking about it and I think there are a few things that we should consider in answering this question.

The first is, the flu shot is very safe. It’s been given to hundreds of millions of people every year since the 1940s. You can’t get the flu from the flu shot because it’s made from the proteins of dead flu viruses. The most common side effect is a sore arm and serious side effects are very rare. It is safer to get the flu shot than to not get the flu shot and risk the potential complications of influenza, even for a healthy person.

It’s also a reality that health-care professionals are more likely to get seasonal influenza than other adults. In healthy adults flu symptoms can range from mild and similar to a common cold, to illness severe enough to require hospitalization. Symptoms typically last a few days, but the fatigue and cough can sometimes last for weeks. So even as a healthy person if you do get the flu it can really interrupt your everyday routines, work, or your vacation plans.

It’s also important to understand that influenza is contagious. If you’re infected, you can spread the virus even if you don’t have symptoms or only have mild symptoms. You could be spreading the flu to others without even knowing it.

These are things that are all worth considering when you make the decision about whether or not to get the flu shot. Also, the sooner you get it, the sooner you’re protected.