DR. WALKER

Immune Escape

What is it?

Immune escape, also known as immune evasion or antigenic escape is a phenomenon in which the host’s immune system is incapable of recognizing and responding to the pathogen (Chiranjib Chakraborty1*†, 2022). The ability of immune escape is acquired by the pathogen during its evolution process, mainly through mutations, which then help the pathogen to go unnoticed in the host body. The most worrisome part however, is that the right variant could be so resistant that its able run around the human immune system without detection. Such “immune escapes” could mean that people who have had the shot remain susceptible to reinfection, and that current vaccines will, at some point, will become useless.

What kind of virus achieves immune evasion?

Both the DNA and RNA viruses can evade the host’s immune system through several pathways. Therefore, vaccines against such viruses are rendered useless, as they figure out ways to surpass the immune system. The respiratory viruses, such as coronaviruses, rhinoviruses, and influenza viruses (Kikkert, 2019) and dengue viruses (Juliet Morrison, 2012) have developed functions that enable them to evade the host immune response and carry on their replication process in the host.

Is immune escape a concern for mRNA vaccines?

Historically, few viruses have managed to evolve resistance to vaccines, but then again we have never performed mass vaccination during a pandemic. That being said, immune escape has been a central discussion point and a major concern for mRNA vaccines. In basic terms, when a virus is under pressure through mass vaccination programs, the vaccine-induced-antibodies will hinder only the virus it was originally designed to neutralize. Variants that have been produced are unlikely to be neutralized by previous vaccine-induced-antibodies or by older vaccines. This then allows new variants to enter the host with little means of the host being able to neutralize the variant. To that end, a person that is vaccinated with the previous version of a vaccine, would have little to no defense against a new variant. Again, the immunity developed by these vaccines, in people who receive them, do not protect them from constantly evolving variants. As we look around, we see mutations arising and spreading multiple times, across the globe, which really is strong evidence that there's some evolutionary advantage for the virus; this really speaks strongly in support of immune escape. Additional vaccinations will only continue to pressure the variants allowing new variants to emerge.

References:

Chiranjib Chakraborty1*†, A. R.-S. (2022). A Detailed Overview of Immune Escape, Antibody Escape, Partial Vaccine Escape of SARS-CoV-2 and Their Emerging Variants With Escape Mutations. Frontiers in Immunology, 1-26.
Juliet Morrison, S. A.-S. (2012). Innate Immunity Evasion by Dengue Virus. Viruses, 397–413.
McKie, R. (2022, January 9). Global spread of autoimmune disease blamed on western diet. The Guardian.
Kikkert, M. (2019). Innate Immune Evasion by Human Respiratory RNA Viruses. Journal of Innate Immunity, 4-20.