The Philippines allows in vaccinated tourists from 157 countries and territories, including Vietnam, starting Thursday without quarantine requirements.
They are only required to furnish a certificate proving they are fully vaccinated against Covid and a negative test result.
Bali in Indonesia also allows entry for Vietnamese tourists, but there is a mandatory five-day quarantine for fully vaccinated travelers and a seven-day quarantine for unvaccinated ones.
Visitors must furnish a negative PCR test result.
On February 1 Thailand began a quarantine-free travel program it calls Test & Go allowing fully vaccinated travelers from Vietnam to enter without quarantine.
In early November Thailand had started allowing fully vaccinated travelers from more than 60 countries to enter but they had to isolate themselves for a day until they received a negative PCR test, but this was suspended in late December following an outbreak of the Omicron variant of Covid.
Laos also reopened its doors to fully vaccinated Vietnamese tourists on January 1 with a test done on arrival and a day's quarantine in their hotel.
But they have to come on package tours with designated travel agencies, and have insurance, including for Covid treatment, worth at least $50,000.
They need to download and register on the LaoKYC and the LaoStaySafe mobile apps prior to arrival, and upload their vaccination certification and test results.
In November Cambodia became the first Southeast Asian country to reopen to international tourism. Visitors had to be vaccinated and furnish negative Covid test results.
Malaysia's National Recovery Council this week agreed to full opening of the borders as early as March 1 without the need for mandatory quarantine.
Vietnam is considering to fully reopen to foreign tourists by the end of March.