https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html
One of many papers you can find talking about the vaccines effectiveness against the original alpha strain.
your link literally doesn't say anything about transmission.
Janine Small, president of international markets at Pfizer, told the European Parliament on Monday that Pfizer did not know whether its COVID-19 vaccine prevented transmission of the virus before it entered the market in December 2020. But Pfizer never claimed to have studied the issue before the vaccine’s market release. -Oct 13th, 2022
At the
hearing, Roos asked Small whether Pfizer had tested its COVID-19 vaccine for its ability to prevent transmission of the virus prior to its market release. Small answered: “No. We had to really move at the speed of science to really understand what is taking place in the market.” She went on to explain why Pfizer moved quickly to develop a COVID-19 vaccine as the virus spread worldwide.
https://apnews.com/article/fact-check-pfizer-transmission-european-parliament-950413863226
what evidence do we have that covid-19 vaccines prevent transmission?
Most papers to date (notably, many are preprints and have yet to be peer reviewed) indicate vaccines are holding up against admission to hospital and mortality, says Linda Bauld, professor of public health at the University of Edinburgh, “but not so much against transmission.”
How could vaccines help reduce transmission?
Vaccines aren’t preventing onward transmission by reducing the viral load—or amount of SARS-CoV-2—in your body. “Most studies show if you got an infection after vaccination, compared with someone who got an infection without a vaccine, you were pretty much shedding roughly the same amount of virus,” says Paul Hunter, professor in medicine at the University of East Anglia. One study,
5 sponsored by the US Centers for Disease Control and Prevention (CDC), found “no difference in infectious virus titer between groups” who had been vaccinated and had not.
https://www.bmj.com/content/376/bmj.o298