Study Confirms It’s Possible to Catch COVID Twice

August 24, 2020 — Researchers in Hong Kong say they’ve confirmed that a person can be infected with COVID-19 twice.There have been sporadic accounts on social media sites of people who say they’ve gotten COVID twice. But scientists have been skeptical about that possibility, saying there’s no evidence it happens.The new proof comes from a 33-year-old man in Hong Kong who first caught COVID-19 in March. He was tested for the coronavirus after he developed a cough, sore throat, fever, and a headache for 3 days. He stayed in the hospital until he twice tested negative for the virus in mid-April.

On Aug. 15, the man returned to Hong Kong from a recent trip to Spain and the U.K., areas that have recently seen a resurgence of COVID-19 cases. At the airport, he was screened for COVID-19 using a test that checks saliva for the virus. He tested positive, but this time, had no symptoms. He was taken to the hospital for monitoring. His viral load — the amount of virus he had in his body — went down over time, suggesting that his immune system was taking care of the intrusion on its own.

The special thing about his case is that each time he was hospitalized, doctors sequenced the genome of the virus that infected him. It was slightly different from one infection to the next, suggesting that the virus had mutated — or changed — in the 4 months between his infections. It also proves that it’s possible for this coronavirus to infect the same person twice.

Experts with the World Health Organization responded to the case at a news briefing Monday.

“What we are learning about infection is that people do develop an immune response. What is not completely clear yet is how strong that immune response is and for how long that immune response lasts,” said Maria Van Kerkhove, PhD, an infectious disease epidemiologist with the World Health Organization in Geneva, Switzerland.

A study on the man’s case is being prepared for publication in the journal Clinical Infectious Diseases. Experts say the finding shouldn’t cause alarm, but it does have important implications for the development of herd immunity and efforts to come up with vaccines and treatments.

“This appears to be pretty clear-cut evidence of reinfection because of sequencing and isolation of two different viruses,” says Gregory Poland, MD, an expert on vaccine development and immunology at the Mayo Clinic in Rochester, MN. “The big unknown is how often is this happening,” he says. More studies are needed to learn whether this was a rare case or something that is happening often.

Past Experience Guides Present

Until we know more, Poland says the possibility of getting COVID-19 twice shouldn’t make anyone worry.

This also happens with other kinds of coronaviruses — the ones that cause common colds. Those coronaviruses change slightly each year as they circle the globe, which allows them to keep spreading and causing their more run-of-the-mill kind of misery.

It also happens with seasonal flu. It is the reason people have to get vaccinated against the flu year after year, and why the flu vaccine has to change slightly each year in an effort to keep up with the ever-evolving influenza virus.

“We’ve been making flu vaccines for 80 years, and there are clinical trials happening as we speak to find new and better influenza vaccines,” Poland says.

There has been other evidence the virus that causes COVID-19 can change this way, too. Researchers at Howard Hughes Medical Center, at Rockefeller University in New York, recently used a key piece of the SARS-CoV-2 virus — the genetic instructions for its spike protein — to repeatedly infect human cells. Scientists watched as each new generation of the virus went on to infect a new batch of cells. Over time, as it copied itself, some of the copies changed their genes to allow them to survive after scientists attacked them with neutralizing antibodies. Those antibodies are one of the main weapons used by the immune system to recognize and disable a virus.

Though that study is still a preprint, which means it hasn’t yet been reviewed by outside experts, the authors wrote that their findings suggest the virus can change in ways that help it evade our immune system. If true, they wrote in mid-July, it means reinfection is possible, especially in people who have a weak immune response to the virus the first time they encounter it.

Good News

That seems to be true in the case of the man from Hong Kong. When doctors tested his blood to look for antibodies to the virus, they didn’t find any. That could mean that he either had a weak immune response to the virus the first time around, or that the antibodies he made during his first infection diminished over time. But during his second infection, he quickly developed more antibodies, suggesting that the second infection acted a little bit like a booster to fire up his immune system. That’s probably the reason he didn’t have any symptoms the second time, too.

That’s good news, Poland says. It means our bodies can get better at fighting off the COVID-19 virus and that catching it once means the second time might not be so bad.But the fact that the virus can change quickly this way does have some impact on the effort to come up with a vaccine that works well.“I think a potential implication of this is that we will have to give booster doses. The question is how frequently,” Poland says. That will depend on how fast the virus is changing, and how often reinfection is happening in the real world.

“I’m a little surprised at 4½ months,” Poland says, referencing the time between the Hong Kong man’s infections. “I’m not surprised by, you know, I got infected last winter and I got infected again this winter,” he says.

It also suggests that immune-based therapies such as convalescent plasma and monoclonal antibodies may be of limited help over time, since the virus might be changing in ways that help it outsmart those treatments.

Convalescent plasma is essentially a concentrated dose of antibodies from people who have recovered from a COVID-19 infection. As the virus changes, the antibodies in that plasma may not work as well for future infections.

Drug companies have learned to harness the power of monoclonal antibodies as powerful treatments against cancer and other diseases. Monoclonal antibodies, which are mass-produced in a lab, mimic the body’s natural defenses against a pathogen. Just like the virus can become resistant to natural immunity, it can change in ways that help it outsmart lab-created treatments. Some drug companies that are developing monoclonal antibodies to fight COVID-19 have already prepared for that possibility by making antibody cocktails that are designed to disable the virus by locking onto it in different places, which may help prevent it from developing resistance to those therapies.

“We have a lot to learn,” Poland says. “Now that the proof of principle has been established, and I would say it has with this man, and with our knowledge of seasonal coronaviruses, we need to look more aggressively to define how often this occurs.”

Sources

Clinical Infectious Diseases, Aug. 24, 2020.

Gregory Poland, MD, consultant, Division of Pediatric Infectious Diseases; consultant, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN.

Maria Van Kerkhove, PhD, infectious disease epidemiologist, World Health Organization, Geneva, Switzerland.

 

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Spotlight On: Ashley Larose

Name: Ashley Larose

Major: Psychology

Role at UNH: Student

Year Started at UNH: 2016

What does being healthy look like to you? 
Being healthy looks like practicing self-care in whatever way an individual sees fit.

What have you been doing to take care of your mental health while in quarantine? 
In order to take care of my mental health, I have been staying in contact with my friends and checking in on them periodically. I schedule social distancing coffee dates with friends where we sit on the roof of our cars and chat. Getting outside has been a huge help, as well as ensuring that I have someone to talk to about things so that it doesn’t stay bottled up inside.

What has been your favorite tech-free hobby? 
My favorite tech-free hobby has been spending time in the sun, whether I am taking my dog for a walk or reading a book.

What do you do to stay active? 
In order to stay active, I created a plan for myself to stick to. It consists of going for a run, practicing yoga, and going on solo hikes.

What has been your favorite food to make while in quarantine? 
My favorite food to make in quarantine has been omelettes in the morning.

How do you find motivation to stay healthy and active while in quarantine? 
A lot of my motivation comes from my dog, because I remind myself that while I can find things to do around the house all day, she can’t go anywhere unless I take her. I also remind myself that when my body feels good, my mind feels good and it makes my days easier and helps in seeing the good in the current situation.

Have you seen or felt any improvements in your physical or mental well-being after making positive changes in your life?
Due to the circumstances, my mental health began to deteriorate, but once I was able to find my new normal and establish coping skills to help me easily deal with day-to-day stress, I have been able to process my emotions in the moment. This has helped me to improve my mental and physical health, and I have been  using physical movement one of my useful coping skills.

Do you have any positive words of encouragement for others to create a healthier lifestyle? 
I recommend doing what works best for you and not what has worked for other people. It could take a while to even find the motivation to begin, but once you start you won’t want to stop. The motivation has to come from you and not someone else.

Spotlight On: Juliana Good

Name: Juliana Good

Department: Public Policy

Role at UNH: Student

Year Started at UNH: 2017

What does being healthy look like to you? 
Prioritizing both mental and physical health is important, and I go to the gym five days a week. I go to the gym because it is a stress reliever. If there are days that I am too tired then I won’t push myself – it is important to also listen to my body and brain.

What do you do to keep UNH healthy?
I am passionate about accessibility and disability policy. A big part of accessibility is removing barriers that make people’s lives harder.

How do you stay fit? 
The gym! I love the gym, it’s really nice and going is a stress reliever. I try to walk as much as I can and I don’t take the bus that often. It’s important to take time everyday to strengthen the body.

Do you have any tips for eating healthy? 
In one of my classes right now we work with Michael Pollan’s work and in summation of what he says, we should “eat food, not too much, and mostly plants.” UNH dining halls have healthy options too. I try to stay away from things that are processed and I appreciate the Wildcat Plate.

How do you find motivation to stay healthy and active on campus? 
If I don’t do the things that I need to do in order to stay healthy, then I will become unhealthy and get sick. Health looks different for everybody, and I’m fortunate that I have found a rhythm and it makes me feel better. Coffee keeps me motivated through the week and any day that I have a good laugh is a good day. I try to find positive connections with people, my professors, friends, and the people I work with.

Have you seen or felt any improvements to your physical or mental well-being after making positive changes in your life? 
Big time! It took a while to find rhythm for how much I wanted to workout, what I eat throughout the week, and what I do throughout the week. This semester I have started to find balance and stride and I feel more energized and have been sleeping better, which as been a really nice thing.

Do you have any positive words of encouragement for others on campus to create a healthier lifestyle?
Ask yourself: if I do this thing now, will I feel better or worse in the next hour, tomorrow, or next week? This frames my decision-making, and it helps me decide what is a good future for myself.