COVID-19 and influenza: preventing two illnesses

Amid the ongoing coronavirus pandemic, there also is another respiratory illness to prepare for, as flu season is just around the corner. A Baylor College of Medicine infectious diseases expert discusses handling flu while combatting COVID-19. 

“We take flu season very seriously every year, but this year it is especially important, since we’re now experiencing two respiratory infections that can have severe consequence simultaneously,” said Dr. Jill Weatherhead, assistant professor of tropical medicine and infectious diseases at Baylor.

When should I get my flu shot?

The influenza vaccine typically becomes available toward the end of August or early September. It takes about two weeks after vaccination to develop adequate antibodies to protect against influenza. Weatherhead suggests getting your flu vaccine during September or early October, prior to the onset of cases within the community. However, it is never too late to get your vaccine during the influenza season.

“As long as there’s active, circulating virus within the community, it’s always a good time to get your flu shot – even if you don’t get it until later in the season,” she said.

Which flu vaccine should I get?

The flu virus is always evolving, so each year the vaccine is updated or adapted based on predictions of what flu viruses will most likely be circulating. Depending on your age, the vaccine slightly differs in terms of potency. Individuals above the age of 65 should receive a high-dose vaccine. Anyone under 65 should take what is available, which is the trivalent or quadrivalent vaccine that will have different vaccine strains within it. 

• Trivalent vaccine: contains influenza A strains (H1N1 and H3N2), as well as an influenza B strain.
• Quadrivalent vaccine: contains the same components, as well as an additional influenza B strain.

When does flu season begin?

Flu season can start early fall. Depending on the year, it can start in August. You may see an uptick in cases in September or October, but there is typically more widespread transmission after October.

When can children start getting the flu vaccine?

Children can start getting vaccines at six months of age, which is highly recommended because young children are very high risk for flu complications.

“Children with COVID-19 can become ill, but compared to adults, the chance of them having complications is much lower,” Weatherhead said. “In comparison, children under 5 and particularly those younger than 2 years old are at high risk of having influenza complications.”

Getting children vaccinated early and making sure individuals around the child are vaccinated is crucial.

Who is high risk for the flu?

Those at risk for complications from the flu are young children, adults over 65 years old, pregnant women and those with underlying health conditions or weakened immune systems.

How do I know if I have the flu or COVID-19 when the symptoms are very similar?

Standard flu symptoms include fever, muscle aches, coughing, shortness of breath and fatigue. The overlap in symptomatology is significant, but there are a few isolated symptoms that are unique to COVID-19: the loss of taste or smell.

“There is significant overlap in clinical symptoms between influenza and COVID-19, making it difficult to differentiate the two diseases based on symptoms alone. Epidemiologic information, such as being in contact with someone who had the flu or COVID can help to aid in diagnostic accuracy,” Weatherhead said.

In these cases, testing is important to try to differentiate which virus is causing the symptoms.

Can I have the flu and coronavirus at the same time?

When coronavirus became more widespread, the flu season was diminishing locally, so there’s minimal information on flu and COVID-19 co-infection. It is possible to have co-infection, although there is no data on having both the flu and COVID-19 simultaneously just yet.

Can the flu vaccine combat COVID-19?

The flu vaccine will not prevent you from getting COVID-19, but it will prevent you from getting severely ill from influenza, and hopefully reduce the risk of requiring hospitalization. You can still get the flu if you have the vaccine, but it could be preventative and reduce symptoms and complications.

“If we can prevent flu disease by increasing community flu vaccination rates, then it would reduce flu infections, flu-related severe disease and flu-related deaths within the community and subsequently reduce the burden on our healthcare system while still trying to control COVID-19 within the community,” Weatherhead said.

How can I know if I need to be tested for the flu or COVID-19?

Once there is documentation of viral transmission within the community, healthcare professionals will start testing for both at the same time as it is challenging to differentiate COVID-19 and flu based on symptoms alone.

If I get the flu, am I more at-risk for COVID-19, and vice versa?

You are not necessarily more at-risk in terms of getting infected, although any time you have a weakened immune system from any sort of other infectious pathogen, you could be at risk for additional infection.

“There is a lot more to learn about co-infection, your immune response when you have an infection and whether it makes you at risk for the other, or if damage from one puts you at risk for a more severe disease from the other,” Weatherhead said.

What can parents and caregivers do to prevent their children from getting the flu?

A lot of the same strategies parents are teaching children to prevent COVID-19 also can help combat the flu: physical distancing, wearing a facial covering and washing hands as frequently as possible.

Where can I get my flu shot?

Influenza vaccines will be available through your primary care physician. If you are concerned about exposure in such a setting, call your doctor’s office in advance to discuss their safety protocols. In addition, flu vaccines are widely available outside your physician’s office. Many standard pharmacies and grocery stores will carry it, as well as mobile clinics. For children, call the pharmacy beforehand to ensure they carry the correct dose for the age of the child. Contact your healthcare provider or public health department to find locations.

Will the flu season be lighter this year with the implementation of social distancing?

The mitigation strategies used for COVID-19 could play a major role in combating influenza or a severe influenza season this year. Because it spreads similarly through respiratory droplets, strategies to reduce viral transmission such as physical distancing and wearing facial coverings will help prevent a severe outbreak, if these measures are continued.

It’s important to remember that one of the major differences between the two illnesses is that treatments exist for the flu, but there is no standard of care for coronavirus just yet, healthcare providers are still discovering what other health factors contribute to outcomes.

“For the flu, not only is there a preventative vaccine, but we have post-exposure prophylaxis, as well as an anti-viral treatment regimen, typically using Tamiflu, but preventative and treatment regimens as well as vaccine development is still underway for COVID-19,” Weatherhead said.