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In three months, the P1 variant went from 0 to 91% of cases in the Sao Paulo state. That seems kind of a big deal since the P2 variant (which was completely snuffed out in the meantime) that was prevalent during the holiday season appeared to have some fitness advantage already, perhaps due to the E484K mutation.
There was no difference among age groups concerning its prevalence among hospitalized people, however, and neither a difference in viral load.
So it seems plausible it could behave more like the South African variant than the British one (both P1 and the SA one being less capable of inducing the formation of syncytia in the lungs, compared to the UK variant or the basal strain; and the SA variant also caused less severe lung disease in Syrian hamsters compared to the UK one).
This is why, again, counting on some anecdotal reports of some doctors is terrible journalistic practice. The UK variant seems it could be genuinely more aggressive (although the UK tracking app contradicts this), but neither the SA nor P1 seem to be, unlike earlier reports would suggest. And none of the three, too, are particularly more aggressive toward younger people (which was kind of expected since all coronaviruses behave the same, unlike influenza and RSV).
