Even with more than 1 million deaths worldwide and 210,000 in the United States, the notion persists that COVID-19 is just another flu.
Not true, said Clifford Martin, MD, vice president and chief medical officer of OSF HealthCare St. Mary Medical Center in Galesburg, Illinois. The novel coronavirus known as SARS-CoV-2, which causes COVID-19, is significantly different from influenza.
“It’s a highly contagious virus, and it’s a much deadlier virus,” Dr. Martin said.
Major differences between flu and COVID-19
There are many similarities between COVID-19 and the flu. Both attack the respiratory system and present the same type of symptoms, such as fever, cough, sore throat and congestion.
COVID-19 also can be marked by breathing difficulty, loss of taste and smell, nausea, vomiting and diarrhea. It attacks the respiratory and neurological systems (lungs and brain), as well as the heart, kidneys and other organs.
The flu and COVID-19 differ in additional ways.
“When COVID-19 starts to come on, it’s a little more delayed,” Dr. Martin said. “There is often a phase where it’s just more of the mild systems, and then a week later, it starts to intensify.
“It really seems to create a much more intense inflammatory response in the body. The virus overwhelms the system, causing blood clotting and scarring. It does have some really long-lasting effects, particularly for those individuals who get the most ill.”
Influenza can overwhelm a person, too, and even land them in the intensive care unit (ICU).
“But each year when we see that with influenza, we see what we call normal ICU progression – two or three days in ICU and they start to improve,” Dr. Martin said. “Maybe they go to a less intensive care bed for a little while and then home. But folks with COVID-19, sometimes we see weeks on end of needing ICU care, and then ultimately, sometimes lives are lost.”
Influenza can also kill, but the mortality numbers are exponentially smaller than COVID-19 deaths. Dr. Martin said an estimated 28,000 Americans died from influenza during the 2018-19 flu season. That’s about 14% of the number who died during the first six months of the pandemic.
Herd immunity takes time
Influenza is contagious and can be deadly, but society at large is able to cope because it has been around for a long time. Dr. Martin notes the flu pandemic of 1918-20, which killed an estimated 50 million worldwide and nearly 700,000 in the United States. Over the past 100 years, the medical science community has learned a lot about influenza.
People who become infected with a virus create antibodies that help them fight off future infections. Vaccines perform the same function. The combination limits the number of people the virus can infect, reducing opportunities for it to spread. This creates the phenomenon known as “herd immunity.”
Dr. Martin said 80% of the population would need to develop individual immunity to reach herd immunity.
“It just takes time,” he said. “We need a vaccine for COVID-19. But even if, all of a sudden, next week we could miraculously vaccinate the whole country, we’re still talking weeks before we would see it start to take effect. And we all know it takes much longer than that to vaccinate people.”
Protect yourself and your community
So far, we know that COVID-19 is highly contagious and potentially deadly. This is especially true for older people and individuals with underlying health problems. It also leaves some people with long-lasting health complications.
And, unlike influenza, it can be spread by infected people who never get symptoms.
“COVID-19 just spreads faster because it can,” Dr. Martin said. “We have seen that one or two individuals in a community quickly turns into 10 to 15, and that 10 to 15 into a thousand and so on.”
Meanwhile, as COVID-19 continues to march, flu season has arrived to present health care systems with what Dr. Martin calls “a double-whammy.”
You can help minimize the impact on your community by getting a flu shot and following the basic steps to minimize the spread of COVID-19: good hand hygiene, maintain physical distancing (at least six feet) and wear a mask in public.