A colleague recently asked me about the difference between issuance rates for two types of non-immigrant visas: tourist (B-2) and student (F-1). The question was in reference to a summer program for students at her university. (Note: A B-1 visas is for business.)
The FY2022 stats from the US State Department confirm my answer, which is that it’s much easier to obtain the former than the latter. While I don’t have the F-1 numbers for Vietnam because the US Mission will not release that information, the worldwide stats are available on the State Department website (PDF download). The issuance rates for F-1 and B-1/B-2 visas were 65% and 79.45%, respectively, which means the refusal rates were 35% and 20.55%.
The FY2022 adjusted refusal rate for B visas (PDF download) in Vietnam was 14.98%, meaning the issuance rate was 85.02%. Adjusted refusal rate equals: [refusals minus overcomes] divided by [issuances plus refusals minus overcomes].
F-1 Visas
Issued: 411,131
Refused: 220,676
Total: 631,80765
B1/B2 Visas
Issued: 3,228,199
Refused: 835,003
Total: 4,063,202
Shalom (שלום), MAA

Unprecedented Student Visa Denials in 2022: 35% Rejected (31.5.23) https://www.cato.org/blog/unprecedented-student-visa-denials-2022-35-rejected