How Your Immune System Reacts to the Common Cold

Your immune system jumps into action to perform two jobs when you get a cold: Fight off the infection and help prevent it from affecting you again in the future. In doing this, it is responsible for most of the symptoms you experience when you catch the common cold, from a cough to congestion.

Tolerating cold symptoms might be a lot easier if you knew that you're both getting better and not going to get a cold again. But even with all of the work your immune system puts into fighting off a virus, at least the latter part of that is unlikely given just how many cold viruses you may come in contact with and what it takes for your immune system to be able to identify them.

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What Happens When You Catch a Cold

The viruses that cause the common cold attach themselves to the cells that line your nasal passages and sinuses. They enter the cells and begin replicating. It takes about two days until they reach the point at which they trigger the body's reaction to fight off the virus.

The infected cells release chemical messengers, called cytokines, that set off an inflammatory reaction. Blood vessels dilate to help an influx of white blood cells reach the area. This swelling contributes to stuffiness and pain in the affected airways. The white blood cells release even more chemicals to fight off the virus, resulting in more inflammation. Eventually, the excess fluid can result in a runny nose and cough.

The immune system is actually overreacting to the virus, as cold viruses don't cause the cell destruction that influenza viruses do. The discomfort you feel due to sore throat, congestion, nasal discharge, and phlegm is primarily due to the effects of the immune response, not damage from the virus.

Developing Immunity to Colds

Your white blood cells become sensitized to the virus causing the infection and begin to produce antibodies. These are proteins that attach to viral proteins and signal white blood cells to destroy the virus.

Some antibodies to that virus remain in your body long after the infection has resolved, and your body will make more of them if you are exposed to the same virus again. This will provide a faster response and possibly prevent the infection from occurring again.

However, there are an estimated 200 different cold viruses—and you will rarely face the same one twice. The common cold is often caused by rhinoviruses. These viruses can also cause sinus infections and ear infections, and trigger asthma attacks. Other possible causes of a cold include respiratory syncytial virus, parainfluenza viruses, adenovirus, coronaviruses, and metapneumovirus.

While you might indeed now be able to thwart re-infection with a virus you've already had, there is likely to be another in your future for which your body hasn't yet had a chance to develop an antibody defense.

Despite your immune response, you are likely to get two to three colds per year.

Will There Ever Be a Common Cold Vaccine?

Vaccines are used to expose your immune system to viral or bacterial proteins and provoke antibody production without being exposed to the disease-causing organism itself.

The problem when it comes to the common cold is that each of the different viruses have unique sets of proteins. While it might be possible to make a vaccine to one cold virus, that wouldn't protect you against the other 199.

A Word From Verywell

Several factors can affect how well your immune system can fight back against the common cold and other illness, not the least of which is your general health, as some conditions (and treatments) can lower your immune response. Still, there are things you can do to support your immune system in its efforts. Among them: Following a nutritious diet, getting routine exercise, managing stress, and committing to about eight hours of sleep every night.

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