Respiratory viruses and vaccines: common questions answered

Sujata H. Ambardar, MD, is an infectious disease specialist at Inova. As cold and flu season ramps up, she shares important information about respiratory viruses and the role of vaccines in safeguarding the community’s health.

It’s winter, and ‘tis the season for respiratory illness. The coughs, sniffles, sore throats and fevers seem to be everywhere this time of year. To help keep you and your family healthy, here is what you need to know about respiratory illnesses and vaccines as you navigate the colder months.

What respiratory illnesses are most common in the fall and winter?

When we talk about the viruses that tend to circulate in the fall and winter and cause respiratory illness, there are three that are most significant in terms of potentially causing severe illness: influenza, COVID-19 and respiratory syncytial virus (RSV). There are other viruses in circulation that are not as severe, like the common cold, and there are also bacterial or allergic causes of respiratory symptoms.

Flu, COVID-19 and RSV all cause such similar symptoms that it can be difficult to tell from symptoms alone which virus is to blame. Common symptoms include:

• Fever
• Body aches
• Fatigue
• Cough
• Trouble breathing
• Sore throat

The National Foundation for Infectious Diseases has a handy chart that shows which symptoms are most likely for each virus.

Why are vaccines important in slowing the spread of respiratory viruses?

While most people who get sick with flu, COVID-19 or RSV recover at home, these viruses can land people in the hospital or intensive care unit, especially if they’re in a high-risk group such as people who:

• Are older than 65
• Have a chronic disease such as COPD, asthma, cardiovascular disease, HIV, etc.
• Have a weakened immune system (immunocompromised)
• Are pregnant
• Are younger than 2 years old (in the case of RSV in particular)

When is the best time to get a flu vaccine?

While we generally advise people to get their flu shots in September or October, flu season can continue as late as May, so getting it later can still be helpful. Flu immunity takes a couple of weeks to reach full strength, and it typically wanes over time. Getting the shot in early fall typically gives you the best chance of being protected when flu cases rise, which is generally in the winter months, but better late than never.

If you have an opportunity to get the vaccine, even if it’s not perfectly timed, my advice is to get it. If you wait, you may forget about it, or it may be more of a hassle later on.

Each year, experts develop flu and vaccines based on extensive global data to determine how the flu virus is evolving and which variants are most likely to circulate. How well the vaccine matches a given season’s virus is one factor that contributes to whether a flu season is mild or not. The severity of flu also depends on how many people have been vaccinated or have some natural immunity.

What about this year’s vaccine?

This year’s flu vaccine covers both Flu A and B, the most common strains of the flu. Most flu shots are inactivated vaccines. That means the virus is not live, so it produces a good immune response and can be given in immunocompromised individuals.  

There is a lot of good, reliable data that shows year after year that the flu vaccines prevent hospitalizations and deaths from influenza, especially for people over age 65. I encourage everyone to get the flu vaccine each year unless they have a specific reaction or contraindication to the vaccine. In that case, they should discuss with their primary care physician how to best manage in respiratory season.

There is now a vaccine for RSV too, right?

Yes. The RSV vaccine is recommended for people between the ages of 60 and 74 who have one risk factor for severe RSV, and it’s also recommended for everyone ages 75 and older. Talk with your primary care provider to find out whether the RSV vaccine is appropriate for your specific situation.

Is there a way to find out which respiratory illnesses are circulating in the community?

The Virginia Department of Health has a free resource available online that tracks flu, COVID-19 and RSV rates by county, week by week. The data is based on test results from primary care or urgent care visits, so while it doesn’t cover every case, it does provide a reliable picture of trends. The site also identifies whether virus levels are mild, moderate or severe and where outbreaks are happening.

What about other respiratory illnesses, like pneumonia or whooping cough?

Pneumonia is a lung infection that can have a viral or bacterial cause.  Pneumonia is often a secondary infection, which means someone who has flu, COVID or RSV can develop pneumonia.  Risk of severe illness and hospitalization from pneumonia are similar to risk from flu, COVID or RSV. Individuals with chronic illness or an immunocompromised condition are at more significant risk.

There are now vaccines designed to protect against the most common and severe types of pneumonia. These vaccines are recommended for people at higher risk of pneumonia (those older than 65, people with chronic conditions, immunocompromised people and those who are pregnant). It is FDA approved for anyone over age 50. If you are 50 or older, or if you fall into one of these higher risk categories, talk with your primary care provider about whether a pneumonia vaccine is right for you.

Pertussis, more commonly known as whooping cough, is better controlled now because an effective Tdap vaccine has been available for years. However, it’s important to keep in mind that it is still present in the community. It spreads easily through airborne droplets when an infected person coughs, sneezes, talks or even laughs.

The Tdap vaccine covers tetanus, diphtheria and pertussis and lasts for 10 years before a booster shot is needed. Caregivers of older adults, infants or other vulnerable populations should make sure to keep their Tdap and other vaccinations up to date to prevent spreading disease.

Why do people sometimes get the flu, COVID or RSV, even though they’re vaccinated?

A helpful way to think about the vaccines for these common respiratory viruses is that they work in several ways:

• They can boost your immunity to the disease, so you are less likely to become ill if you encounter the virus
• If you do get sick, they can reduce the severity and length of your illness – so even if you get the flu, for example, you might bounce back within a few days rather than being confined to bed for weeks
• The vaccines are also very good at preventing hospitalization or death from these viruses

In sum, while there is no guarantee that a vaccine will stop you from getting sick this winter, the vaccine can help your body fight back and bounce back quickly, so you don’t end up in the hospital with severe illness.

What’s your most important piece of vaccine-related advice?

Vaccines are one of the best tools we have to prevent disease, saving lives and reducing hospitalizations in the process. No matter what your age or health condition is, talk with your primary care provider about what vaccines are recommended for you and when.