No promises were made and the word promise does not appear in the article.
The results were extremely positive . The vaccines effectiveness exceeded all expectations. The effectiveness in preventing infection was expected to be around 50% but the studies showed it to be over 90%.
"Before the first results, the talk was of a vaccine that offered maybe 50% protection" . "I don't think any of us really hoped that the vaccine would be 94% effective at preventing Covid-19 disease, that was really a stunning realisation."