Filenews 16 March 2021
There is growing evidence that the various most contagious mutations and variants of coronae find fertile ground to evolve and appear in the bodies of people with weakened immune systems such as cancer patients.
A coronae usually accumulates mutations at a slow but steady rate of about two per month. The vast majority of them have no impact on the transmission of the virus, which is why they go unnoticed. But that's not always the case. For example, the British variant B.1.1.7 acquired 23 mutations that did not exist in the original virus detected in China and which - most importantly - appeared almost all together.
Why are mutations so contagious?
Experts estimate, according to the New York Times, that there is only one good explanation for this: at some point the coronavirus infected a man with weakened immune systems, which allowed him to adapt and evolve much faster than usual. "This seems to be the most likely explanation," said Cambridge University professor of clinical microbiology and iology Ravindra Gupta.
To the extent that this is indeed the case, it makes vaccination of people with weakened immune systems a priority, according to the infectionist Dr. Adam Loring of the University of Michigan, which is indeed applied by several countries. The faster and more universally these people are vaccinated, the lower the risk that their body will become an "incubator" of new mutations of the coronavirus, in case they become infected by it.
However, according to Loring, due to the possible reduced immune response of their body, the vaccine may not "work" as well in them, so in the future they will probably need additional treatment with monoclonal antibodies against coronae.
How mutations work in people with weak immune systems
In most people infected with coronavirus, the active infection lasts about a week, which is not enough for the virus to acquire more than one mutation at most within the patient's body. That's why it's extremely rare for most people to have mutations that make coronae more contagious. But in a man with a weak immune system, the process of mutations is easier, as the virus can remain in their body for many months, thus having sufficient time for immune mutations.
If a significant mutation is transmitted from the immunocompromised person to someone else, then it can spread quickly like a fire, as seemed to be the case with the British variant of corovirus and perhaps also with South African and Brazilian. "It is quite possible that these (variants) have come from people with permanent infection," said evolutionary biologist Katrina Lithgow of Oxford University.
What diseases may favour the appearance of new mutations
The list of conditions that cause problems or weakening in the immune system is long (from diabetes and rheumatoid arthritis to leukaemia and lymphoma) and experts disagree on which of them may favour the emergence of new mutations of coronavirus. Some argue that the list should include all seniors, as well as those taking drugs that suppress the immune system and anyone who does not produce adequate antibodies.
Some scientists like Loring are more concerned about people with blood cancers, but not, for example, those taking rheumatoid arthritis medications. In any case, scientists stress the need not to stigmatize or incriminate people with weakened immune systems and to emphasize how to reduce their exposure to coronavirus.
Source: RES-BE
