Debunking Common Myths About Colds and Influenza

As we enter peak season for cold and flu, it’s important to separate facts from fiction. Let’s bust some of the myths and misconceptions through a clinical lens.

Myth: The common cold and flu are the same

Reality: Although they share some symptomatic overlap, the common cold and influenza are distinct infectious processes caused by different viral families with varying degrees of severity. Colds are normally mild, respiratory infections caused by rhinoviruses and other pathogens. Symptoms like nasal congestion, sore throat, and sneezing usually resolve within 7-10 days. [1]

Flu, on the other hand, is a more severe illness caused by influenza A and B viruses, and less frequently C viruses. It causes more intense symptoms like high-grade fever, chills, body aches, headache, weakness and fatigue, and has a longer recovery period of 2+ weeks. Flu can also lead to complications such as pneumonia. [2]

Myth: Vaccines protect against the common cold

Reality: There are over 200 subtypes of viruses that can cause the common cold, and they mutate frequently. This means that exposure to one cold virus does not provide full immunity against other cold viruses, making one vaccine against all causes of the common cold impossible.

Influenza (flu) vaccines provide protection against a small specific subset of virus subtypes. New flu vaccines are made every year, based on which are most likely to impact the population. [3]

Because of this, these vaccines do not provide immunity against every possible type of flu. so there's still a chance you might get the flu after vaccination. However, if you do get the flu after vaccination, it's likely to be milder and not last as long. [4]

Myth: Natural exposure can give you immunity from colds 

Reality: When you get a cold, you make antibodies against that specific virus strain. But these antibodies start fading after about a year. Also, cold viruses change frequently. This disguises them from your immune system and allows them to reinfect you later on, despite you having those antibodies. Because there are numerous cold viruses that keep mutating, natural infection can't give you lifelong immunity, just temporary defence against that one virus.

Myth: Common colds are entirely preventable

Reality: There are ways to reduce the risk of contracting a cold virus – such as avoiding symptomatic individuals, proper hand hygiene and wearing a mask. [6]

That said, they can’t completely eliminate the risk of common cold, as it’s highly contagious.

Myth: Cold weather causes a cold 

Reality: Although more cases of cold and flu happen during the colder months, this isn’t actually due to the cold temperatures. It’s more likely due to a variety of factors, including:

• Schools are in session, increasing the risk for exposure to the virus.
• People stay indoors more and are in closer proximity to each other.
• Low humidity causes dry nasal passages which are then more susceptible to cold viruses.

Viruses can move through the air in droplets when you sneeze or cough. These are then spread by hands or may live on contaminated surfaces like door handles. This means that crowded or enclosed spaces, such as public transport, schools and the workplace are the perfect breeding ground for viruses. [7]

Myth: Antibiotics work for cold and flu 

Reality: Doctors don't recommend antibiotics for flu because they won’t relieve your symptoms or speed up your recovery. In fact, it may put you at increased risk of antibiotic resistance in the future. [8]

Myth: You can’t get the flu vaccine if you’re pregnant

Reality: You should have the flu vaccine if you're pregnant to help protect you and your baby. It's safe to have a flu vaccine at any stage of pregnancy. If you’re pregnant during flu season, your hospital may give you the option to get the flu jab at one of your routine prenatal appointments, or at your GP’s surgery. [9]

References:

1. Heikkinen T, Järvinen A. The common cold. Lancet. 2003 Jan 4;361(9351):51-9. doi: 10.1016/S0140-6736(03)12162-9.
2. National Institute for Health and Care Excellence
3. World Health Organisation
4. NHS
5. National Library of Medicine
6. American Lung Association
7. BUPA
8. NHS
9. NHS