So your body has responded but you haven't ended up with a full blown cold or you haven't been laid out sick for a number of days or weeks. So this would be a sign of a healthy immune response, but a person who doesn't get sick at all is not necessarily a healthy response.
Research suggests that, on average, each individual picks up around 200 colds in their lifetime. But some people seemingly never get ill and don't take their fair share of the sickness pie. So what is their secret? According to science, there isn't one (yet).
Some people are simply more susceptible to getting sick than others. Lifestyle choices, environment, genetics, and age play key roles in determining immunity. Even if you cannot entirely control your immune system, fostering healthy habits might help protect you against infections.
As long as your immune system is running smoothly, you don't notice that it's there. But if it stops working properly – because it's weak or can't fight particularly aggressive germs – you get ill. Germs that your body has never encountered before are also likely to make you ill.
Why Some People Evade Colds And Others Don't People who have built up immunity to common viruses are less likely to get sick. But researchers say it's also possible some people are genetically less susceptible to catching a common cold.
Recent studies have shown that women have a better immune system against infections than men. This is due to the genetic structural difference. This genetic structure is known as microRNAs.
“Some of us inherit a set of immune system genes that are particularly good at dealing with one particular virus,” explains Daniel Davis, professor of immunology at the University of Manchester and author of The Compatibility Gene, which explores how immune system genes shape our biology.
Adults average about 2 to 4 colds a year, although the range varies widely. Women, especially those aged 20 to 30 years, have more colds than men, possibly because of their closer contact with children.
The Centers for Disease Control and Prevention estimates that the average adult has two to three colds per year, and children typically get more.
The function of the immune system peaks at around puberty and gradually declines thereafter with advance in age.
You Have Frequent Infections
Having more than four ear infections in one year. Developing pneumonia twice during a one-year period. Suffering from chronic sinusitis or more than three episodes of bacterial sinusitis in a year. Needing more than two courses of antibiotics a year.
Blood tests.
Blood tests can determine if you have typical levels of infection-fighting proteins (immunoglobulins) in your blood and measure the levels of blood cells and immune system cells. Having numbers of certain cells in your blood that are outside of the standard range can indicate an immune system defect.
He continues, “There is an active immune response which accounts for the resistance of certain people getting sick, and that response is just as active as the response we all know and hate, which is being sick with the sniffles, fever, coughing and sneezing. It's just that the responses are different.”
Nosophobia is when you have a persistent, irrational fear of contracting a chronic, often life-threatening disease like cancer or AIDS. Nosophobia differs from illness anxiety disorder (hypochondria), which causes you to worry about all types of sicknesses.
Everyone gets sick. Despite all the vegetables we eat or vitamins we gulp down, sooner or later pathogens such as viruses and harmful bacteria infiltrate our bodies, and we need to take a time-out. We sit back and let our immune system do its job. But when it comes to getting sick, not all immune systems are equal.
While adults shouldn't expect to get more than two to four colds a year, this goes out the window if you have young children. That's because once kids start daycare, they're on track for six to 12 colds a year.
“Researchers are exploring why some people are more susceptible to cold and flu viruses. While we don't have all the answers, we believe that your environment, genetics and immune system play a key role in determining your risk for these illnesses.”
Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. For example, the skin acts as a barrier to block germs from entering the body. And the immune system recognizes when certain invaders are foreign and could be dangerous.
People may have resistance to infections because of their genetic make-up. For covid-19, this has been investigated in relation to people's risk of dying from or needing respiratory support due to their infection.
Females have a higher innate immune response than males. Females produce lower levels of inflammatory mediators and increase the production of immunosuppressive molecules to reduce systemic inflammation.
“Seventy percent of the immune system is located in the gut,” says David Heber, MD, PhD, professor emeritus of medicine at UCLA Health. “Nutrition is a key modulator of immune function.”
While it will be some time before we have answers from these studies, scientists do believe there is a small group of people who are naturally immune to SARS-CoV-2 owing to their genes.
Older adults are at highest risk of getting very sick from COVID-19. More than 81% of COVID-19 deaths occur in people over age 65. The number of deaths among people over age 65 is 97 times higher than the number of deaths among people ages 18-29 years.