Innovation Pharmaceuticals Inc (IPIX)

[farrell90]

Below is a summary of an article from the New England Journal of Medicine:

"Antibodies induced by currently available mRNA vaccines can still neutralize the Delta and Kappa variants of the SARS-CoV-2 virus, but do so at a reduced potency, according to a report published in the New England Journal of Medicine.

The Delta variant, first identified in India and previously known as B.1.617.2, is now dominant in the United States. The Kappa variant, previously B.1.617.1, was also first identified in India.

Compared with the Washington strain that arrived in the United States last year, vaccine-induced antibodies are 2.9 times less able to neutralize Delta and 6.8 fold less able to neutralize Kappa. Still, researchers concluded that the antibodies induced by mRNA vaccines will be strong enough in many people and protective immunity is “most likely retained” against Delta and Kappa."

http://news.emory.edu/stories/2021/07/coronavirus_delta_kappa_vs_vaccine_antibodies/index.html

The real answer is we are not likely to know which is the best path for previously infected for some time. The current reports often conflict.

You have to agree the Delta variant is less responsive to antibody based therapies, Monoclonal antibodies, convalescent sera and vaccines than previous Covid viruses.

The most disturbing information is the break through infections seen in Israel and England where so many vaccinated individuals were hospitalized and died. Obviously the vaccinations are safer than the primary infections and confer lower hospitalization and death rates. Why is it the vaccines do not provide better protection?

Currently we do not have an adequate explanation for these illnesses. Is it because the vaccines lose potency with time.Obviously the variant mutations change the S protein structure and change its antigenic profile. Individuals differ in their immune responses. Does innate immunity produce a better T cell response?

This article discusses T cell immunity in vaccinated and in patients previously infected, but it also made this observation

"The ratio of serum virus neutralization GMT to recombinant RBD-binding IgG GMC is lower after immunization with BNT162b1 than after infection with SARS-CoV-2. As noted previously, this difference may be attributed, in part, to BNT162b1 eliciting antibodies that bind epitopes that are exposed on the RNA-encoded RBD immunogen but buried and inaccessible in the spikes of SARS-CoV-2 virions, differentially increasing RBD-binding IgG GMCs after immunization. In addition, infection with SARS-CoV-2 might elicit neutralizing antibodies that recognize epitopes that are exposed on virions and located outside the RBD, differentially increasing the serum neutralizing GMT after infection29,30.

https://www.nature.com/articles/s41586-020-2814-7

Good luck,

Farrell