It's not too late to get flu vaccine or COVID-19 booster shots Why you should get them

It’s not too late to get a flu shot and a COVID-19 booster.

The flu is an infection due to influenza virus, and COVID-19 is due to a coronavirus. Both are spread from an infected person to someone else via droplets from coughs, sneezes or even talking.

They can also be spread when an infected person has droplets on their hands and touches something that is then touched by someone who infects themselves by touching their own mouth or nose. The close quarters of being huddled inside due to cold weather, as well as the seasonality of these illnesses (particularly the flu, as COVID-19 is more year round) makes the winter months common for outbreaks.

These viruses rapidly mutate, minimizing the ability of people’s immune systems to fight them off. In order to "prime" the immune system, a yearly vaccination for flu and a booster for COVID-19 have been developed, aimed at the type of virus predicted and/or going around. It seems that this year’s flu vaccine, and the most recent COVID-19 booster, are good matches for the strains we're now seeing.

How a flu vaccine is administered

There are two major ways to make a flu vaccine. One is by using inactivated strains of the "predicted" flu strains (the yearly vaccine is developed against the three major candidates for the year’s flu). This is the type that is given by injection, and is called TIV (trivalent inactivated vaccine). The other major vaccine production method relies on a live virus that is manipulated so as not to be able to multiply (live attenuated influenza vaccine, or LAIV). This type of vaccine is squirted into the nose.

How is a COVID booster administered?

COVID-19 boosters are similar to the original vaccinations but are modified to be a better match to the "strain" endemic at the time. These are given by injection.

Who should take COVID and flu vaccines?

A flu vaccine is recommended for everyone over 6 months of age unless they have a contraindication (discussed below). LAIV is approved for people 2-49 years old. TIV should be used for other age groups, with intradermal (under the skin) vaccination a possibility in those 18-64. Children 6 months to 8 years old should get two doses separated by a month (unless they had two doses in a previous year, in which case one dose is sufficient). Everyone else typically requires one dose.

A COVID-19 booster is recommended for everyone 5 years and older who has already completed the full COVID-19 vaccine series. Because children younger than this may not have gotten a full course of the initial COVID-19 vaccine, they may need multiple doses (including the most recently updated booster).

Flu and COVID-19 vaccinations are especially important in high-risk people, such as those over age 65, health care workers (to prevent them from spreading disease to their patients), pregnant women, and those at risk for complications if they get the sick (such as those with lung or heart disease, or those who are immune-compromised).

There are people who shouldn't get vaccinated, but they are few

A history of certain illnesses (such as Guillain-Barre syndrome within six weeks of having had a flu or COVID-19 vaccine) may indicate that a patient should not get a vaccination. And the live attenuated flu vaccine should not be given to anyone with a compromised immune system, lung disease (such as asthmatics or those with COPD), cardiovascular disease, diabetes, kidney insufficiency, pregnant women, children younger than 2 or close household contacts of these patients (TIV should be used instead).

What are the symptoms of vaccination?

Arm soreness in those getting an intramuscular vaccination, runny nose for those getting intranasal administration, and/or minor "flu-like" symptoms may occur after flu or COVID-19 vaccinations. But this should not dissuade people from getting vaccinated.

What are the symptoms of getting either the flu or COVID?

The flu and COVID-19 can each become life-threatening illnesses, especially for those who have not been vaccinated. Since the original outbreak, COVID-19 has killed well over a million Americans, and hospitalized close to 7 million. The hospitalization and death rate from the flu varies quite a bit from year to year, with 100,000 to 700,000 people hospitalized each year, and anywhere from five to 55,000 dying.

Despite the seriousness of these illnesses, and the easy availability of vaccinations, less than 50% of adults over age 18 have received this year’s flu vaccine, and less than 20% have obtained the seasonal COVID-19 booster. These low vaccination rates are allowing much higher levels of illness and death, and are a major driver in the pressure that increased sick people present to emergency departments, being hospitalized and dying.

Although earlier would have been better, it's not too late to get vaccinated. See your doctor or go to your local pharmacy and get this done. It's OK to get them both at the same time — that’s how I got mine.

Jeff Hersh, Ph.D., M.D., can be reached at DrHersh@juno.com.

This article originally appeared on MetroWest Daily News: COVID-19, flu: Vaccines work, and here's why most should get them