Chinese Sinovac vaccine seems to work better in monkeys than the Oxford U/Astrazeneca vaccine.
Sinovac:
https://www.sciencemag.org/news/2020/04/covid-19-vaccine-protects-monkeys-new-coronavirus-chinese-biotech-reports#
Vaccinated monkeys who received highest vaccine dose had no detectable virus in respiratory system 7 days after exposure to SARS-CoV-2. Lower dose monkeys had detectable virus for a while but then suppressed it.
Oxford:
https://www.biorxiv.org/content/10.1101/2020.05.13.093195v1.full.pdf
Vaccinated monkeys had detectable, shedding virus in respiratory system after exposure, but did not have accelerated breathing, lung damage, or other clinical effects of disease. They were infected but asymptomatic. However, the monkeys were euthanized after a while (to biopsy lungs), they didn’t follow them to see if they’d eventually become symptomatic.
EDIT: I probably shouldn’t have posted that without doing more research. The Oxford vaccine mentioned is not the one that went into human trials.