Chile has some interesting real-world data on the effectiveness of vaccines against a mostly Gamma/Lambda outbreak.
CoronaVac had 87% VE vs. hospitalizations, 90% ICU admission, 86% deaths. Meanwhile, Pfizer had 97% VE vs. hospitalizations, 98% ICU admission, 92% deaths. Limitation of the study: the Chilean healthcare system was rather strained during this period, so efficacy against hospitalization might have been overstated, and against deaths, understated.
It might seem not like a huge difference but it means 4 - 5 times more people end up needing a hospital/ICU bed after being double vaccinated with CoronaVac than Pfizer. This is the sort of discrepancy that might end up having a significant effect with a Delta variant wave (see Seychelles and Mongolia, where most adults were vaccinated with the similar Sinopharm vaccine).
