She gives COVID tests and vaccines to her animals. She has never tested positive for the disease. What is her secret?
Michaeleen Doucleff/NPRI panicked when my daughter was exposed to the disease.
November 2020 was before vaccines were available. A person in the class tested positive and was in the classroom for two days. We were all prepared for a few weeks of sickness.
Nothing had happened after 10 days. There were no signs of an infection or positive test for it. She had not been affected by the virus.
The same thing happened about 10 months later. 2 weeks later. And 4 months later. We did the same routine after each exposure. Wait. And do it again and again.
My daughter has been exposed to the disease at least 4 times. Most of the time at school. At a party. She seems to have escaped an illness every time.
My question is why.
The simplest answer is that she has been exposed to an infectious disease. We missed it despite all of our testing. According to an analysis from the Centers for Disease Control and Prevention, at least 42% of children under the age of 18 have been exposed to the disease. The US has only recorded 13 million cases of children. There are a lot of carbon dioxide cases among kids. It is possible that Rosy will fall into that category.
She is just as likely to fall into the category of kids who haven't caught it even though they have been exposed to it.
How has it been done by Rosy? She pulled the rabbit from the hat or the coronaviruses from her nose.
Several studies over the past year have shown that some people are good at clearing the virus from their respiratory tracts before they get a vaccine. There are four key immune cells that can be used to fight another coronaviruses, and an arm of the immune system that gets little attention in the media.
The University College London published a study in the journal Nature that left many other scientists a bit surprised. Mala Main says that before the full data was published, there were people who said, "Oh, how is it possible?"
Maini and her colleagues analyzed the blood of about 60 health-care workers at a hospital over and over again. It was during the first wave of the Pandemic. Despite being exposed, the workers tested negative for the disease.
Maini wondered if the health workers had a protective element in their blood. It is possible that their previous encounters with other coronaviruses had created immune cells that could fight off a disease.
Maini says that it looked like in this small subset of people.
She and her team found a group of T cells in the blood of 20 health-care workers that could recognize and stop the disease.
Cross-reactive T cells are special cells. T cells are thought to be second-line defenders in the immune system, Maini says.
She found that the T cells appear at a very early stage of the disease. The cells are called cross-reactive because they recognize different types of coronaviruses. Cross-training involves several different sports and cross-reactive cells work on different viruses.
19 of the 60 health workers showed signs of an infectious disease. At the same time, these cross-reactive T cells rapidly replicated inside the health-care workers blood, and right away the infection stopped. The T cells appeared at the same time as the cessation of the infection. Maini and her colleagues theorize that the T cells were able to protect them from an overt infection.
People who had higher levels of these cross-reactive T cells, at the baseline, didn't have missing or present cross-reactive T cells.
The kicker is that these special T cells probably came from the health-care workers. The coronaviruses that can strike humans were likely caused by their immune systems.
Maini says the most likely candidate would be the common cold coronaviruses.
Seasonal coronaviruses are the cause of about 30% of colds. These viruses have been making people sick for a long time. All four of them are caught before age 5 or 6.
Even though these seasonal coronaviruses don't cause a lot of symptoms, you still have to clear the virus from your body to prevent it from turning into a more serious problem. The immune system makes T cells that recognize coronaviruses. Some of the T cells stay around and watch out for the virus, or a similar one, to return again. The body cannot afford to keep a whole T cell arsenal at the ready.
If you have the right genes, some of your T cells will be able to help stop the disease. Maini thinks that between 10 and 15% of people have cross-reactive T cells.
Brianne Barker is an immunologist at Drew University in New Jersey. All the colds I and Rosy had before the swine flu could be helping her fight off the disease.
There are a lot of things to consider in this study. Maini says that the experiment took place during the first wave of the epidemic, when the virus was different than it is now. Maini doesn't know if the T cells would be able to stop omicron.
Donna Farber at Columbia University says it is an association, but it is difficult to say what it is. There are a number of mechanisms that can be used to stop the virus in its tracks.
A study published in Nature Communications in January supports a role for cross-reactive T cells in fighting an infectious disease. The study looked at immune responses in people living with an infectious person. The presence of cross-reactive T cells correlated with protection against infections.
T cells are not the only immune component that can cross-react. Raiees Andrabi is a vaccine immunologist at the Scripps Research Institute. He and his team have evidence that the immune system brings the seasonal coronaviruses back into action.
He says that researchers don't know how much protection these cross-reactive antibodies give.
There is a 100% guarantee that she has another protective device if her immune system doesn't have cross-reactive T cells. It is a powerful one.
The SARS-CoV-2 is clever. It has figured out a way to get inside the respiratory tract. The cell has a trick up its sleeve.
It is called the RIG-I pathway. It is an early-warning system for viruses which destroys the virus inside the cell and prevents it from spreading to surrounding cells.
Inside your respiratory cells, tiny molecule called RIG-I receptors, recognize and bind to a virus's genome. Once a RIG-Ireceptor sticks to a piece of viralRNA, it launches a massive immune response. This response kills the cell, protects the surrounding cells and possibly brings in immune cells to help control the infection.
Barker says there is evidence that the RIG-I pathway can clear out a SARS-CoV-2 infection before the immune system even knows it is there.
Some people are better able to detect the disease inside their cells than others.
Barker says there is evidence that some people are making a stronger RIG-I response.
A study published last month in Nature Biotechnology found that children have more RIG-I receptors inside their nose than adults. The higher concentration helps them respond quicker to infections.
There is emerging data that shows the immune response in children is a little bit more sensitive and may react a bit stronger to different viral infections.
At the end of the day, she says, it was luck that helped her respond to the exposure. It depends on her previous encounters with other coronaviruses. Barker says how many RIG-I receptors she has inside her cells is determined by the latter.
Donna Farber at Columbia University says that children are really, really good at stopping infections with new viruses because they are essentially all new.
A new pathogen is very rare for adults. We don't see new ones very often. She says that children are better able to respond to new pathogens than we are.
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