J&J has two pre-print studies going out for publication on its efficacy based on 8 months of studies. They claim it is roughly 85% effective overall, and confers strong antibody production against the South African and the new Delta variants.
The article in the OP makes a suggestion that the Pfizer vaccine, which was I believe to have been most widely used in Israel, has dropped to the 64% range in terms of overall efficacy. Suggests that whatever benefit it may deliver at first (original claim 95% reduction in severe illness or death) seems to wane rather rapidly considering it’s only been a few months since its released - and its wide adoption by Israelis.
A feature, not a bug. More booster shots.