SARS-CoV-2 has four antigens. The existing vaccines stimulate the production of antibodies against only one of them, the spike protein.
The existing vaccines are proving ineffective against Delta because it has mutated significantly enough that its spike protein does not cause a neutralizing immune response. They may even be causing ADE, as evidenced by the most recent data comparing Israel and Palestine.
The existing vaccines are proving ineffective against Delta because it has mutated significantly enough that its spike protein does not cause a neutralizing immune response. They may even be causing ADE, as evidenced by the most recent data comparing Israel and Palestine.