Your link doesn't address better protection against variants specifically, just better protection against reinfection in general. The linked study specifically states that it does not include delta.
Here you go: https://www.science.org/doi/10.1126/scitranslmed.abi9915
>The vaccines offer better protection against variants than having had COVID and recovering.
The cost/benefit overall is much more complicated than this simple statement.
for example: how are you personally, materially harmed by taking the vaccine?
that would be the cost
The benefits:
Unknown increase in immunity against alpha strain
Unknown increase in immunity against variant strains
...
The Costs:
Chance of currently known adverse effects
Chance of unknown adverse effects specific to vaccination of people with prior immunity.
Some recent data [1] suggests that those with prior covid infection 13X lower chances or reinfection with delta than those with 2 vaccine doses. If this is accurate, it begs the question of how much benefit is gained by vaccination on top of existing immunity in comparison to to the rare but known side effects.
https://www.science.org/content/article/having-sars-cov-2-on...
For some with naturally acquired immunity, Both costs and benefits are amazingly small!
If you are a healthy 18 year old (infection fatality 1/100,000)[1] w/o vaccine, plus have previously acquired immunity 13X better[2] than a vaccine 90+% effective, you are talking about about 1/ 10s of millions of chance of death or severe complications IF you are infected. This easily puts it in competition with the more serious vaccine complications.
Looking at just two aspects for this hypothetical individual, you could weigh
1/10 million chance of death with no booster vaccine shot VS 17/100,000 chance of bells palsy[3] and a 60% chance of fever, chills and headache.
https://www.nature.com/articles/s41586-020-2918-0 https://www.science.org/content/article/having-sars-cov-2-on... https://www.fda.gov/media/144413/download
>Currently available information is insufficient to determine a causal relationship with the vaccine
is all your evidence for a non-negligible cost this flimsy?
Similar nonzero observations have been made in other national studies with sufficiently large samples.[1]
Some countries have added additional content around it to the prescribing info [2].
Scientific consensus is that the risk is clearly is lower than covid.
Another rare but acknowledged side effect is mycarditis.
We can quibble about the rates but they do exist.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3...
https://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-s...
https://www.aappublications.org/news/2021/06/10/covid-vaccin...
An analysis looking at the trial data puts it at 14-18/100k higher than the expected baseline
https://www.thelancet.com/journals/laninf/article/PIIS1473-3...
A analsys from the previously linked lancet study had a muck larger sample ~500k, but different collection methods and found smaller but nonzero results
>The age-standardised difference for the incidence compared with the background population was 41·5 (95% CI 11·7 to 71·4) for CoronaVac and 17·0 (−6·6 to 40·6) for BNT162b2, equivalent to an additional 4·8 cases per 100 000 people vaccinated for CoronaVac and 2·0 cases per 100 000 people vaccinated for BNT162b2.
Most if not all the vaccine trials saw small increases <1% in serious adverse events in the treatment arm