Two takeaways from this article:
1. Prior COVID-19 don’t need the vaccine. Study says people who had Covid-19 already have good T-cell antibody levels. (Vaccine boosted is “somewhat”.)
2. Further study needed: Why are the vaccine T-cells not providing protection against breakthrough infection?
From what I’ve read, it’s been hypothesized that, unlike the earlier variants, the Indian variant (Delta) makes a home first in the nasal cavity and upper respiratory system and replicates rapidly there. It takes time for the T-cell immunity in the blood to recognize the infection and begin fighting the infection.
In short, this is why there is strong protection against serious disease but only moderate protection against symptomatic infection and transmissibility.
It’s going to take a nasal vaccine to be able to stop transmission of this variant. Several nasal vaccines are in the pipeline.
Both Flu and Kennel Cough vaccines don’t do this, same Corona virus, different strains. As are common colds. Each are yearly.
At 73 never had the Flu, just a few colds. Ear infections are more frequent. Swimmers Ear, Meniere’s. 2 attacks, treatment caused hearing loss.
All Vaccines are FDA APPROVED. Even the ones which damaged my hearing.