Some of what know about the coronavirus has seemed clear from the start, and some has evolved as doctors have gained experience with the disease. Here’s the current thinking on some common questions regarding COVID-19:
Does the flu vaccine affect my chances of getting COVID-19?
The flu vaccine protects you from seasonal influenza, not the coronavirus — but avoiding the flu is especially important this year.
Health experts and medical groups are urging people to get either the flu shot or nasal spray. That’s mainly so that doctors and hospitals don’t face the extra strain of having to treat influenza in the midst of the coronavirus pandemic, straining their ability to treat people.
Also, the two illnesses have such similar early symptoms that people who get the flu might mistakenly think they have COVID-19, says Dr. Gregory Poland, an infectious disease specialist at the Mayo Clinic. Only a test can tell the two apart.
The U.S. Centers for Disease Control and Prevention recommends the flu vaccine for everyone starting at 6 months oold and suggests getting it by the end of October.
The CDC says the vaccine won’t cause you to get the flu and that the protection it provides takes about two weeks to kick in. And the flu vaccine isn’t perfect but studies show if the vaccinated get sick, they don’t get as severely ill.
A few flawed studies over the years have attempted to link the flu vaccine to increased risk of other respiratory infections, but experts say there is no evidence that’s true.
How long can I expect a COVID-19 illness to last?
How long you might be sick with coronavirus varies. Most coronavirus patients have mild to moderate illness and recover quickly. Older, sicker patients tend to take longer to recover. That includes those who are obese or have high blood pressure and other chronic diseases.
The World Health Organization says recovery typically takes two to six weeks. One U.S. study found that around 20% of non-hospitalized individuals ages 18 to 34 still had symptoms at least two weeks after becoming ill. The same was true for nearly half of people 50 and older.
Among those sick enough to be hospitalized, a study in Italy found that 87% were still experiencing symptoms two months after getting sick. Lingering symptoms included fatigue and shortness of breath.
Dr. Khalilah Gates, a Chicago lung specialist, says many of her hospitalized COVID-19 patients still have coughing episodes, breathing difficulties and fatigue three to four months after infection. She says it’s hard to predict exactly when COVID-19 patients will return to feeling well.
“The unsettling part of all this is we don’t have all the answers,” says Gates, an assistant professor at Northwestern University Feinberg School of Medicine.
It’s also hard to predict which coronavirus patients will develop complications after their initial illness subsides.
COVID-19 can affect nearly every organ. Long-term complications can include heart inflammation, decreased kidney function, fuzzy thinking, anxiety and depression. It’s unclear whether the virus itself or the inflammation it can cause leads to these lingering problems, according to Dr. Jay Varkey, an Emory University infectious diseases specialist.
“Once you get over the acute illness, it’s not necessarily over,” Varkey says.
Am I immune to the coronavirus if I’ve already had it?
If you’ve been infected with the coronavirus, you have some immunity — but how much and for how long are big unanswered questions.
There’s evidence that reinfection is unlikely for at least three months even for people who had a mild case of COVID-19. That’s how long New York City researchers found stable levels of protective antibodies in a study of nearly 20,000 patients of the Mount Sinai Health System.
So far, reinfection has been rare. The best known example: Researchers in Hong Kong say a man had mild COVID-19 and then, months later, was infected again but showed no symptoms. His second infection was detected through airport testing, and researchers found that genetic tests revealed slightly different strains of the virus.
That’s evidence that the man’s immune system worked as it should. Very few diseases leave people completely immune for life.
Antibodies are just one piece of the body’s defenses, and they naturally wane over time. And usually “memory” immune cells can identify germs they previously encountered so they’re better at fighting them the second time around. That can help make any repeat infection less severe.
Scientists are studying how the other parts of the immune system kick in with the coronavirus.
It’s not known whether people who’ve been reinfected but show no symptoms would be able to spread the virus to others. That’s why health experts say even people who have recovered from COVID-19 need to wear a mask, keep their distance and practice good hygiene.
What about superspreader events?
It seems that much of the spread of the coronavirus has been caused by what disease-trackers call superspreader events. That’s when a single person infects a large number of other people or when a gathering is linked to a large number of cases.
There’s no rule for when a cluster of cases is big enough to be called a superspreader event. But these aren’t instances of spread within one household. Instead, these are large clusters of cases in which infection occurs in settings such as churches, restaurants and bars.
In the United States, for instance, a choir member with symptoms attended a rehearsal in March. Of 60 others who attended, 52 got sick with COVID-19, including two who died.
In Hong Kong, an outbreak at four bars infected 39 customers, 20 staff members and 14 musicians before ballooning further to infect 33 family members and other contacts. Disease trackers discovered that bands played at all four bars, so musicians might have spread the virus to more than 100 people.
Scientists studying three months of contact-tracing data from Hong Kong estimated that 19% of people infected were responsible for 80% of the spread of coronavirus infections.
To prevent superspreader events, we need to better understand them, says Anne Rimoin, an infectious diseases expert at UCLA who called for detailed contact tracing of the infections around President Donald Trump, including those who attended a Sept. 26 Rose Garden ceremony and indoor White House reception for Supreme Court nominee Judge Amy Coney Barrett.
The timing of the event and the number of people infected suggests the possibility of superspreading, according to Rimoin.
“Contact tracing is the way you get to the bottom of a superspreader event,” Rimoin says. “That’s how you break chains of transmission.”
Unlike many contact-tracing investigations, where it can be difficult to find everybody involved, the White House investigation would have “exquisite records and video about who was where and when,” Rimoin says. “It’s an opportunity to learn about superspreader events that could save thousands of lives, if not millions of lives, in the long run.”
What are the treatment options for COVID-19?
There are several. Which is best depends on how sick someone is.
For example, steroids such as dexamethasone can lower the risk of dying for severely ill patients. But they might do the opposite for someone who is only mildly ill.
In the United States, no treatments are specifically approved for COVID-19, but a few have been authorized for emergency use, and more are being considered. A panel of experts convened by the National Institutes of Health updates guidelines as new studies come out.
Here’s what’s advised for different types of patients:
- Not hospitalized or hospitalized but not needing extra oxygen: no specific drugs recommended and a warning against using steroids.
- Hospitalized and needing extra oxygen but not a breathing machine: the antiviral drug remdesivir, given through an IV, and in some cases also a steroid.
- Hospitalized and on a breathing machine: remdesivir and a steroid.
What about convalescent plasma, an infusion of blood from a COVID-19 survivor that contains antibodies that fight the virus? Not enough is known to recommend for or against it, according to the guidelines.
Still, enough is known to advise against hydroxychloroquine and certain drugs that affect the immune system. Multiple studies have found them ineffective against the coronavirus.
Aside from drugs, doctors have learned more about ways to treat people who are hospitalized with coronavirus, such as putting them on their bellies and other measures that might prevent the need for breathing machines.