Latest data from Israel (between Jan 16 and Feb 06)... They compared two groups to distinguish the potential effects of the vaccines vs. a lockdown currently implemented in Israel.
Group 1: > 60 of age, 90% vaccinated
Group 2: < 60 of age, ~30% vaccinated
New cases: Group 1 dropped by 50%; Group 2 dropped by 20%.
Hospitalization: Group 1 dropped by ~40%; Group 2
increased by 15%.
Severe cases: Group 1 dropped by ~30%; Group 2
increased by ~30%.
Efficacy of the Pfizer vaccine against the UK variant is still 90-95%, same as the other less transmittable strains. No data on the South African variant.
The Pfizer vaccine may also lower the chances of transmission since the viral load on those with vaccines is much lower. that makes them less likely to spread the virus. Still too early to be sure though... but a good sign.