Perhaps that editorializing seems to push a narrative, when the Lancet study doesn't contain the word "massively" at all.
To quote the single-sentence summary of the study, "All study vaccines boosted antibody and neutralising responses after ChAd/ChAd initial course and all except one after BNT/BNT, with no safety concerns", flies in the face of what most people anecdotally know with regards to vaccine safety, which could be interpreted as "pushing a narrative".