"COVID-19 vaccination of the index case reduced infectiousness by 44% (95% CI, 27-57%), vaccination of the close contact reduced susceptibility by 69% (95% CI, 65-73%), and vaccination of both reduced transmissibility by 74% (95% CI, 70-78%) in social settings, suggesting some synergy of effects."
"Conclusions: COVID-19 vaccination reduces infectiousness and susceptibility; however, these effects are insufficient for complete control of SARS-CoV-2 transmission, especially in older people and household setting."
Overall, I think the dominant phenomenon here is people wanted to typecast floating-point data to boolean answers, the media did their best to accomodate that want, and almost nobody reads primary sources.
"Conclusions: COVID-19 vaccination reduces infectiousness and susceptibility; however, these effects are insufficient for complete control of SARS-CoV-2 transmission, especially in older people and household setting."
https://pubmed.ncbi.nlm.nih.gov/36724697/
Overall, I think the dominant phenomenon here is people wanted to typecast floating-point data to boolean answers, the media did their best to accomodate that want, and almost nobody reads primary sources.