Why Do Some Individuals Not Catch COVID?

In any pandemic, health mysteries are there to be solved. The most recent mystery on scientists’ lips is why some people catch COVID and others don’t. What now lies in solving this mystery is the potential development of drugs that could make every individual void of catching COVID and passing it on. 

While Exposed Many Times, Catching the Virus Has Yet to Happen

Some U.S. individuals have been known to be exposed to those infected with COVID more than once; however, despite this, have yet to catch COVID. Other individuals participated in trials involving dripping live viruses into their noses and other deliberate efforts to infect them with COVID. However, all tests revealed no infection from the intentional exposure. 

These individuals, in general, come from families who rarely get sick even if all around them fall ill. Now, the hope is to identify what makes these individuals unable to get infected and, with this knowledge,  be able to develop drugs to protect others against COVID.

The hope is that identifying these mechanisms could lead to the development of drugs that not only protect people from catching COVID but also prevent them from passing it on.

A Possible Reflection of What the Immune System Is Capable of

News sources report that “Possibly, this was a reflection of the immune system rapidly shutting down an embryonic infection… Early immune responses in the nose are associated with resisting infection.” 

The report continues, “Together, these findings imply that there is a struggle between the virus and host, which in our ‘uninfected’ participants results in prevention of infection taking off.”

Uninfected Partipants and What We Now Know

• While some individuals do not catch COVID at all, others may experience mild symptoms, such as a stuffy nose, sore throat, tiredness, or headache. However, this may be the cold or flu and not related to COVID
• Some individuals experience levels of the virus that do not climb high enough to trigger detectable levels of antibodies, inflammatory factors or T cells in the blood
• Some individuals are able to shake off COVID in the early stages of infection (Blood tests  reveal that T cells reactive against Sars-CoV-2, plus other markers of viral infection.)
• Some individuals may have memory T-cells from previous COVID or cold infections  which cross-reacted with the new COVID variant and protected them against infection 
• Some vaccinated individuals who are exposed to COVID, block viral replication and detectable infection 
• Some individuals have cross-protective immune responses due to seasonal COVID
• A pattern of infections could be a reason why some individuals have some kind of protective immunity
• Many who have avoided COVID may be genetically resistant, even if they have some partial immune protection 
• A small proportion of people may even be genetically resistant to COVID 
• Some individuals who do not catch COVID may have common gene variants that provide modest protection against infection or a very rare gene variant that completely protect them against infection
• Some immune responses triggered by H1N1 influenza may equip people with partial, though not complete, protection against COVID
• A genetic defect in some people means they lack a receptor used by the pathogen to enter cells, so they cannot be infected. (Some individuals may have a defect in a receptor that is used by Sars-CoV-2.)

Overall, as reported in the news, “Identifying such genes could lead to the development of new treatments for Covid-19, in the same way that the identification of CCR5 receptor defects in Human Immunodeficiency  Virus (HIV)-resistant people has led to new ways of treating HIV.”

No Immunity Test Available Yet

Understanding how frequently people abort nascent COVID infections in the era of Omicron is complicated because it requires intensive testing – for the virus, antibodies, T-cells, and other markers of infection – and because so many people have been vaccinated.

While much is still to be discovered on why some individuals catch COVID and others don’t, news reports state “There is also no commercially available test that can distinguish between immunity triggered by vaccination and the different variants.”

No Guarantee if Infection will Eventually Happen or Not 

While more is to be researched on this matter, there is absolutely no guarantee that those who have never caught COVID will not eventually become infected. Therefore, all U.S. citizens need to continue health and safety precautions. 

However, the fact that some individuals do not catch COVID is a big sign of hope for the world and the medical industry in their pursuit of a cure.