Hundreds of millions of viruses fall onto every square meter of the ground all around the globe, along with many more bacteria and fungi, daily. Viruses responsible for colds and flu tend to circulate more often during the cold season. Since we are surrounded by so many microorganisms, a very logical question to ask is this: is it possible to have a cold and the flu at the same time? Let’s see what researchers are saying.
Viruses are in competition with each other
Although research is ongoing and more studies are needed to fully understand this process, it appears that viruses and other microbes compete for one with another. In the case of respiratory viruses, they may compete for specific cells to infect in their attempt to multiply and infect humans. It is also possible for the host’s immune response to make it easier for one virus over another to infect the bodily’s cells.
In a 2019 study published in the Proceedings of the National Academy of Science of USA, scientists evaluated data from over 35,000 participants who had tens of thousands of throat and nose swabs. This study assessed the development of respiratory infections over nine years, focusing on 11 types of respiratory viruses, including influenza A and B viruses that cause flu, as well as viruses responsible for common colds such as rhinoviruses, respiratory syncytial virus, and adenoviruses. According to this study, 35% of the participants had positive tests for at least one virus, where 8% showed positive tests for at least two viruses.
Other research studies show that infections with rhinoviruses decrease when cases of flu are at their peak in the winter. There is some evidence that people who get infected with flu (influenza A) are 70% less likely to catch an infection with rhinovirus.
The jury is still out
At this time, it appears that it is unlikely to catch both the cold and flu at the same time. It can be possible, but very unlikely. It seems that one virus is suppressing the others. It is also possible that flu viruses create a response from the immune system that prevents or delays a common cold. Perhaps the other way around is possible as well. Other factors may play a role. For example, when a person is sick with the flu they will stay home to avoid the spread. This means they are less exposed to other people who may have a cold or other infection, and thus less likely to catch another virus.
What is known with certainty
It is well known that bacterial infection can follow a viral infection. For example, bacterial pneumonia can follow a common cold or the flu. The most common bacteria found following flu are Streptococcus pneumoniae, Haemophilus influenzae, Group A Streptococcus, and Staphylococcus aureus. Some strains are resistant to antibiotics. These bacterial infections actually increase the severity of the symptoms, the risk of hospitalization, and even death. After a bacterial infection and/or prolonged use of antibiotics there is a risk of fungal overgrowth as well, especially in those with a weakened immune system and the elderly.
Other factors to consider
As part of the evolutionary process, humans learned to live with microbes and developed a close connection. In fact, about half of the human DNA originated from viruses. Trillions of friendly microbes make up the gut flora, cover the skin, and are found throughout the body. These friendly microbes support the immune system, fight disease-causing germs, are involved in digestion, synthesize vitamins and even influence gene expression. Even within the gut flora, there are different species that compete one with another, but overall there is a balance between different strains.
Infection doesn’t necessarily mean you get sick and develop symptoms. An infection occurs when a virus or another microbe enters the body and starts to multiply. Generally speaking, only a small portion of the infected people will have signs and symptoms of a disease, when the cells get damaged by the infection.
In response to an infection, the immune system starts to work very hard. White blood cells, antibodies, and other processes work together to eliminate the foreign invaders. The symptoms of an infection- like fever, fatigue, headaches, and rashes are actually the result of work done by the immune system in an attempt to eliminate the infection. Fever for example inactivates viruses, while the production of interferon blocks the replication of the viruses.
The bottom line is this. Try to stay as healthy as you can, so your immune system can respond promptly to any virus or microbe. Do not worry about catching a cold and flu at the same time. The symptoms of both infections can be managed with medication like acetaminophen, ibuprofen, and cough medicine and flu shots are widely available to prevent influenza infections. Don’t forget about these simple, yet effective measures to reduce the risk of spreading the infections to others: wash your hands, cover your cough and stay home when sick.