Cough-cough, sniff … Ahhh choo!

Those unsettling sounds from someone nearby are reminders that it’s time to think about preventing fall and winter respiratory illnesses. Influenza, COVID-19, and respiratory syncytial virus (RSV) spread easily through close contact. The best way to protect yourself from these nasty infections is by getting vaccinated. 

Amid the political chatter about vaccines and the government entities that oversee them, it’s understandable to wonder about vaccine recommendations and why it’s so important to get vaccinated. We asked Benjamin Lee, M.D., associate professor of pediatrics at the UVM Larner College of Medicine and a pediatric infectious disease physician at UVM Children’s Hospital, to answer questions about common winter illnesses and the merits of annual vaccines. 

How serious are respiratory diseases like the flu, COVID, and RSV?

BL: For some people, respiratory infections mean a few days of discomfort and missing work or school. For others—especially young children, older adults, and people with compromised immune systems—they can be very serious. Every year, on average we expect to see almost half a million people in the U.S. hospitalized from influenza, and anywhere from 10,000 to 50,000 people are expected to die from it in the winter months. There’s a significant health burden, and that doesn’t even account for missed school, missed work, and the greater effect on the community and the economy.

When is the best time to get these vaccines?

BL: In the northern United States, we see respiratory illnesses start to trickle in as the weather gets cold and then peak during the winter. Here in the northeastern U.S., flu tends to peak around January and February. So, the best time to get these vaccines is October—that’s the sweet spot. The reason is that it takes about two weeks [after the shot] before the vaccines start to become effective, and they will provide protection for months afterward, through the peak of the winter season. However, if for whatever reason you have to get your vaccine a little bit earlier or a bit later, that’s OK; it’s more important to get vaccinated whenever you are able rather than trying to time it perfectly.

“A vaccine may not guarantee perfect protection against a virus, but skipping your shot guarantees you’ll have no protection at all.” — Benjamin Lee, M.D.

Who should get these vaccines?

BL: Everybody who is 6 months of age and older should get a flu shot every year. RSV vaccines are recommended for pregnant people, as the antibodies their bodies make will be transferred to their newborns and protect them. For infants already born but less than 8 months old at the start of the season, two monoclonal antibodies are available, and those with high-risk health conditions, such as prematurity or underlying heart or lung conditions, can get an antibody shot during their second season as well. All adults age 75 and older, and adults age 50–74 with chronic medical conditions or who live in a nursing home can also get an RSV vaccine. The decision for COVID vaccine can be made in consultation with a doctor who will consider individual risk factors, but in general anyone who wants a COVID shot should be able to get one. 

Does getting a vaccine guarantee that you won’t get sick?

BL: Respiratory virus vaccines are not 100 percent effective at preventing infection, so there is no guarantee that if you get a vaccine, you won’t get the virus it’s meant to prevent. But we know that in patients who are vaccinated, the severity of that infection will be far less. If someone who gets a flu shot then catches the flu, they will have far lower risk of having severe infection and need to be hospitalized or develop secondary complications, which can be much more severe than the initial infection itself. 

What are the risks of skipping vaccines this year?

BL: Anyone—even those who are young and healthy—can become very sick, very quickly from these common respiratory illnesses. As I mentioned, the severity of an infection will usually be far less in people who got vaccinated compared to those who did not. A vaccine may not guarantee perfect protection against a virus, but skipping your shot guarantees you’ll have no protection at all.

How are flu shots re-formulated each year to keep them up to date?

BL: Viruses are monitored at surveillance sites around the world throughout the course of a year, with support from the World Health Organization. This data is used by scientific experts to make an informed decisions about which virus strains are the most important ones to include in vaccines in the coming year’s cold and flu season. 

There are now several different ways to make flu shots each year. The most common is to grow the viruses in chicken eggs, and then inactivate them for injection. The inactivated, harmless virus triggers an immune response. Other vaccines are made using recombinant protein technology, and others are grown using cell-based methods. The goal is to make sure we don’t “put all of our eggs in one basket,” so that we have a more diversified vaccine supply.

Should people who are allergic to eggs get a flu shot?

BL: Yes. Even in vaccines with viruses that were grown in eggs, the amount of egg protein that ends up in the flu shot is so minute that there is very little risk. If someone is concerned about this, they can discuss it with their doctor and ask for a vaccine that uses cell-based or recombinant protein technology in their formulation. Either way, egg allergy is no longer a barrier to getting a flu shot. 

Are some vaccines made using mRNA? 

BL: Yes. While messenger RNA (mRNA) technology has been studied for more than 30 years, COVID vaccines became the first vaccines to be authorized for use in the U.S. Instead of an inactivated virus, mRNA vaccines include a piece of virus RNA, which instructs the body to make a protein found on a virus’s outer membrane, spurring the immune system to produce antibodies against the virus. There are currently no approved flu shots that use mRNA vaccines, but several are in clinical development. These mRNA vaccines are going to be critical to future influenza pandemic preparedness because, without question, it’s the fastest way to make a new vaccine. This was well demonstrated with COVID. There’s a lot of intense interest in making sure that mRNA vaccines will be ready to go if needed for rapid public health response, as well as being able to contribute to the seasonal vaccine supply.

What can you tell us about thimerosal in vaccines?

BL: Thimerosal is a mercury-based preservative that has received a lot of attention because some have claimed it is associated with adverse side effects, including autism. It was removed from the U.S. vaccine supply in 2001, with the exception of certain flu vaccine formulations contained in a multi-dose vial, which represent only a tiny fraction of flu shots given in the U.S. This year, the FDA voted to remove thimerosal from these flu vaccines, as well. Thimerosal was never used in vaccines for COVID, RSV, measles, mumps, rubella, varicella (chickenpox), inactivated polio, or pneumonia.

Is there anything about vaccines that concerns you, as a pediatrician and infectious disease expert? 

BL: I am highly concerned that vaccine access and insurance coverage for vaccines will become a major issue moving forward. Vaccine coverage for a range of preventable diseases is falling and will continue to fall as availability, reimbursement, and public confidence in vaccines are at risk in the current setting. Tragically, this will lead to increased deaths and hospitalizations due to completely preventable diseases. Vaccines are the best way for everyone to protect themselves and their loved ones from life-threatening infectious diseases. 

For more information about respiratory illness vaccine recommendations and where to get them, visit the Vermont Department of Health Flu, COVID & RSV Vaccines website.

Watch “Do You Need a Flu Shot?”, an interview with Dr. Benjamin Lee, on Across the Fence