What sense would that reference make? How does geography or national boundary have anything to do with medical trail anyway?
I quote from Lancet's publication of AZ phase III trail:
Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis.
Should AZ's trail be called supersized phase 2?
Because the goals for the trials in China are to track neutralizing antibody level and monitor possible side-effects, which is basically what phase 2 trials are about.
Here's their filing at China Clinical Trials Registry:
Their own description of the primary objectives of their trial in China
Primary Objectives:
Immunogenicity
To evaluate the seroconversion rates, geometric mean titers (GMTs) and geometric mean titer increase folds (GMIs) of S-RBD-specific IgG antibodies as well as neutralization antibodies as measured by pseudovirus and wild-type virus neutralization assays at 14 days following a 2-dose regimen of the SARS-CoV-2 mRNA vaccine at an interval of 28 days in population aged 18 years and above.
Safety
To evaluate the safety and reactogenicity of the SARS-CoV-2 mRNA vaccine to be administered in a 2-dose regimen at an interval of 28 days in population aged 18 years and above.
Evaluating the efficacy should a primary objective for any real phase 3 trial, but it's the case here. Hence it's really a phase 2 trial.
I'm not denying that they are doing real phase 3 trials in other parts of the world (e.g. Mexico).