That study is from November 2020. Pfizer vaccine was granted emergency use beginning Dec 2020.
The current egg dilemma we are seeing likely has its roots beginning in the same time frame. Remember Gates has invested in artificial egg companies and US farmland for some time now. Takes planning to not only decimate the commercial egg industry but also infiltrate the private egg producer's food supply chain, the effects of which we are seeing now.
The silencing of studies like these gave them time to mass vaccinate spike protein into as many people as possible while concurrently destroying any viable treatment options.