I should know better than to read these posts but I couldn’t resist.
Unfortunately “I’ve researched this” now often means “I’ve looked at stuff on the web but don’t know how to select reliable sources or fact check them”. Virology, immunology and vaccinology are incredibly complicated, and the oversimplification that’s needed to publish info on this stuff in a way that can be reasonably understood by non-specialists leads to misunderstanding and distortion. There are also plenty of people who are happy to publish their own ill-informed ideas or thought experiments as if they were facts, and others who just love wild conspiracy theories.
I work in a university, used to do (actual) research and my colleagues are doing a lot of Covid research, including vaccine research. I have read tons of research proposals and findings. None of the Cov vaccines are gene therapy by any practical definition. The research and clinical trials were defined, registered and approved as vaccine trials, not gene therapy trials. The product is defined as a vaccine not a gene therapy product. Its purpose is to be a vaccine - to elicit an immune response against a virus, not to produce a human gene product which is what a gene therapy agent does. None of the vaccines can change your DNA. Some of the techniques involved in the new types of vaccines are in common with techniques used in gene therapy. That does not mean that the vaccines are gene therapy.
Vaccines do not kill off your natural antibodies. The vaccines direct an immune response against the Cov spike protein, not against anything else and certainly not against antibodies. Plenty of people have been tested for natural antibodies and vaccine induced antibodies and found to have both.
As for variants, both naturally acquired antibodies and vaccine-acquired antibodies will protect you against any variant that has a spike protein that’s similar enough to the one your immune system encountered. If a future variant has a different enough spike protein, it will escape both the vaccine and your natural antibodies. This has been known from the start. So far, none of the variants including Delta have completely escaped the vaccines but we do see reduced (but still good) vaccine efficacy, i.e. some vaccinated people will still get sick. This is being very closely monitored and intensively researched. Then there’s T cell immunity which the vaccines also induce - it’s not all about antibodies.
If your colleague can give a link to that claim I’d be very interested to have a look. The most generous interpretation I can think of is that someone read something that had a grain of truth and got confused.
The idea that thousands of lab and clinical scientists like my colleagues, all around the world, have produced vaccines that only work against one variant and destroy natural immunity, then lied to us all about it, is ridiculous and insulting. It would mean they’re all either incompetent or corrupt, and they certainly are not.