Rhinoviruses are the most frequent cause of the common cold, accounting for at least half of all upper respiratory tract infections in humans. This virus is ubiquitous and circulates year-round, though activity often peaks in the spring and fall. An average adult experiences two to three rhinovirus infections annually, while young children may have as many as six to eight episodes each year. This high rate of recurrence leads to a fundamental question: Is lasting immunity to the rhinovirus possible, or are repeated infections simply unavoidable?
The Biological Reason for Repeated Infections
The simple answer to whether a person can be infected by rhinovirus multiple times is definitively yes, and the reason lies in the virus’s vast genetic diversity. Scientists have identified over 165 distinct rhinovirus strains, known as serotypes, which are categorized into three main species: A, B, and C. The surface proteins on each of these serotypes are unique enough that the body’s immune response generated against one strain offers little to no protection against the others.
When the body successfully fights off a rhinovirus infection, it produces specific neutralizing antibodies that provide long-lasting immunity against that exact serotype. These antibodies are highly strain-specific, meaning they recognize and deactivate the specific virus that triggered their creation. However, they lack the ability to effectively neutralize a different serotype that has a slightly altered structure.
This lack of cross-immunity is referred to as antigenic diversity, and it is the primary mechanism that allows for repeated infections throughout a person’s lifetime. Because so many serotypes exist, a person is constantly exposed to new strains that their immune system has not encountered before. Developing a single, broadly protective vaccine against rhinovirus is incredibly challenging due to this wide array of viral targets.
How Rhinovirus Spreads and Survives
Rhinovirus is highly successful at spreading because it can travel through several different pathways, which contributes to its high rate of transmission in communities. The virus is primarily spread via aerosolized droplets released when an infected person coughs or sneezes. These microscopic particles can travel through the air and be inhaled by someone nearby, directly infecting the respiratory tract.
Transmission also occurs through direct person-to-person contact, such as touching or shaking hands with an infected individual. An equally significant route involves contaminated surfaces, known as fomites. Rhinovirus can be deposited onto objects like doorknobs, light switches, remote controls, and counters when an infected person touches them after wiping their nose.
The virus is relatively stable outside a host, capable of remaining infectious on hard, nonporous surfaces for more than 25 hours under certain conditions. The virus transfers easily from these contaminated surfaces to a person’s fingertips. Once on the hands, the virus is often transferred to the nasal mucosa or eyes when the person touches their face, leading to a new infection.
The survival and spread of rhinovirus are also influenced by environmental factors, particularly low humidity and cooler temperatures. These conditions, which are common indoors during the winter months, can enhance the virus’s ability to remain viable on surfaces and in the air.
Symptom Management and Prevention Strategies
Currently, there is no specific antiviral medication or cure for a rhinovirus infection; treatment focuses entirely on alleviating symptoms while the immune system clears the virus. Supportive care is the mainstay of therapy and includes getting adequate rest and maintaining hydration by drinking plenty of fluids. These measures assist the body’s natural defense mechanisms and help soothe irritated respiratory tissues.
Over-the-counter medications can provide temporary relief from the most bothersome symptoms. Nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen can help manage fever, headache, and body aches. Nasal decongestants can be used to reduce nasal stuffiness, though they should be used cautiously and for only a few days to avoid rebound congestion.
Minimizing the risk of transmission requires the consistent application of practical hygiene strategies:
- Rigorous hand hygiene, which involves frequent washing with soap and water, is a highly effective way to remove the virus from the skin. If soap and water are not available, an alcohol-based hand sanitizer can be used as an alternative.
- Avoid touching the face, specifically the eyes, nose, and mouth, as these are the primary entry points for the virus.
- Disinfect frequently touched surfaces in the home and workplace to reduce the viral load on fomites.
- Cover coughs and sneezes with a tissue or the upper sleeve, rather than the hands, to limit the spread of infectious droplets.