Hooker said the more the variant deviates from the original sequence used for the vaccine, the less effective the vaccine will be on that variant. This could explain why fully vaccinated people are getting infected with the Delta variant, Hooker said. But this isn’t the case for natural immunity, he explained.
“The vaccine focuses on the spike protein, whereas natural immunity focuses on the entire virus. Natural immunity — with a more diverse array of antibodies and T-cell receptors — will provide better protection overall as it has more targets in which to attack the virus, whereas vaccine-derived immunity only focuses on one portion of the virus, in this case, the spike protein. Once that portion of the virus has mutated sufficiently, the vaccine no longer is effective.”