As a clinical physician, the term immunocompromised is applied to a very small number of people whose immune systems really do not work well enough to prevent them from dying from common infections or, in the case of COVID-19 vaccines, responding optimally to the vaccines to develop immunity.
A healthy immune system
A “healthy” immune system keeps us from having “something that is not us” in our bodies, be it another organism (a virus, bacteria, parasite, etc.), a splinter, or a transplanted organ or tissue. (Thankfully women have a very functional “immune deficiency” when it comes to growing someone different from them in their womb. Otherwise I wouldn’t be writing this article, and you wouldn’t be reading it!)
Virtually all of us have a healthy immune system that the majority of the times prevents life-threatening illness from common infections. However many infections can cause devastating consequences despite having a healthy immune system. A common example is the polio virus or the Ebola virus or the West Nile virus.
There are also conditions like cancer, that is “something that is not us” that seems to escape our immune system’s detection and eradication. The specifics of how that happens within a healthy immune system is still being worked out.
Life on planet Earth
As I have said before, “All will become immune to this new organism, whether it is through surviving the illness or getting vaccinated.” This is just basic biology on planet Earth.
The vast majority of us have a healthy immune system capable of reacting to and fighting against invading organisms. Most of the time that system works well. If we do die from an infectious disease, it is rarely due to our immune system not working as hard as it can.
When a new virus evolves and spreads into the human population, a pandemic ensues, because the human population has never been exposed to this virus and had the chance to develop immunity. Eventually almost all humanity will develop immunity to this new organism. It will be by illness or vaccination. There will always be that small number that do not have immunity because of lack of exposure. But everyone in the world exposed to others who have been exposed to others will develop immunity.
Immunity is developed by exposing one’s body to a substance or organism and having our immune system respond to it. Without a previous exposure, no immunity is present.
The good news is that vaccination provides a potential for developing immunity without the need to become ill from a specific bug.
However one’s general immunity is often a progressive process. An example is that some people get Strep throat, because they had not been exposed to and developed immunity to that particular strain of Strep. They may have had Strep throat before, but not to this strain. Eventually after enough exposure or illness, people become immune to enough Strep strains that they don’t get throat infections from Strep.
Studies have shown that children who play outside rather than staying indoors all the time, have fewer infectious illnesses. Also studies have shown that people who are compulsive hand-washers have a greater incidence of respiratory infections.
It appears that ongoing exposure to the bugs in our environment conveys better immunity as seen by less respiratory and gastrointestinal illness.
We all had no immunity to this new SARS-CoV2 virus, but we also were not immunocompromised in the sense that we had an immunologic deficiency.
Virtually all of us have good immune systems. We just haven’t had the chance to get exposed and develop immunity by virtue of illness or vaccination.
We are not immunocompromised in the way we use that term in medicine.
So what about our responses to the COVID-19 vaccines?
All of us who are not truly immunocompromised will respond in some way to vaccination. However all of us may not get a strong enough response to convey complete protection against future exposure from the vaccine.
In the specific case of the SARS-CoV2 virus, the Pfizer and Moderna vaccines appear to produce excellent and sustained stimulation of our immune system for at least 10 months after vaccination. How long that initial protection lasts will only come with further study.
Based on data about protection against the first few strains of the SARS-CoV2 virus, they provided 90+% protection against infection. With the Delta variant that protection number seems to have fallen to about 70%.
The Johnson & Johnson as well as the AstraZenica vaccines prevented illness about 70% of the time against the first several strains. They provided partial immunity as represented by fewer hospitalizations in 83% of vaccinated individuals. Since then the J&J vaccine has been shown to less protection against the newer mutations or variants of the SARS-CoV2 virus.
Again, the Pfizer and Moderna vaccines still appear to be protective against illness from the newer variants, although that protection rate seems to have dropped to about 70%. (Here the term “protection” means preventing the illness.) Even if they don’t prevent illness, they appear to provide partial immunity, especially from the delta variant, as manifest by generally less intense illness and lower hospitalization rates from these breathru infections. That partial immunity is obeserved as a roughly 80% reduction in hospitalization from the delta variant, even before a third booster.
However the J&J vaccine appears to be progressively less protective against the newer variants in terms of prevention and reduced risk of hospitalization.
As best we can tell, people who are truly immunocompromised do not get the protection as completely as others with healthy immune systems. These people may get COVID-19 as if they were never immunized.
Breakthru infections
Breakthru infection is the term used for getting COVID-19 after vaccination.
Those who get a breakthru infection after vaccination have a healthy immune systems. The issue is that they have incomplete or partial immunity against the delta variant of the SARS-CoV2 virus.
Thankfully the booster, or third Pfizer or Moderna vaccine, further reduces the risk a additional 90+% of the likelihood of development of severe illness that would result in hospitalization and death.
Vaccines
The primary purpose of vaccines is to prevent death or disability (like with polio). Ideally it prevents illness also, but that is not always the case.
Just because people are getting ill after getting the mRNA COVID-19 vaccines does not mean the vaccines aren’t effective.
At present the Pfizer and Moderna vaccines have proven safe and very effective against the current coronavirus.
