A study published in the proceedings of the National Academy of Sciences revealed that the COVID-19 virus has adapted to evade the antiviral protein called interferons. Interferons are the front-line defense of the innate immune system in the human body. Though the adaptive immune response defends against the infection by generating antibodies and T cells, the innate immune response is the first line of defense generated by recognizing the conserved molecular pattern in pathogens.

Dr. Eric Poeschla, Professor of Medicine, at the University of Colorado School of Medicine state that the COVID virus is seamlessly adapting to evade innate response. The research team tested up to 17 different human interferons and found that some of the interferons, such as IFN alpha-8 were strongly inhibited by the invading SARS-Cov-2. Importantly, the later variants have developed significant resistance to their anti-viral effects. 

Interferons are the central molecules in the innate immune system that trigger a cascade of antiviral responses in cells within seconds of infection. Hence, the interferon plays a significant role in reducing the viral load produced by an infected individual.

(Source: https://health.economictimes.indiatimes.com/news/diagnostics/covid-variants-have-developed-resistance-to-human-immune-system-study/93153232 )