That sounds about right. Russian/Chinese vaccines?
Discussion
I know someone from Argentina stuck in Mexico City trying to get into the US denied for Russian vaccine.
Just looked up, Russian.
That would do it.
Canada was ok with the Chinese/Russian vaccines. Probably because Canada only cared that you complied, not whether or not it worked...
I'd say get a fake cert. But that's probably not so easy now that very few people are getting vaxxed.