Staff from the academy vaccinated 2,000 students aged 10-18 years from Satriwithaya School, Roong Aroon Learning Centre and Santisuk School, with the approval of their parents.
The doses were administered at the National Telecom head office building, reports the Bangkok Post.
The CRA plans to jab 180,000 students from 132 schools in Greater Bangkok who have applied to the academy for vaccination. There is no charge.
Sinopharm has not been approved for use on schoolchildren by the Food and Drug Administration, which endorsed only the use of the Pfizer vaccine for students.
CRA secretary-general Nithi Mahanonda said Sinophram was safe for young people. The Chinese-made vaccine used inactivated virus and had already beem given to young people in China, Chile, Sri Lanka and the United Arab Emirates.
The campaign would continue until all schoolchildren who registered had been vaccinated, Dr Nithi said. He expected it would end in mid-October.
The academy would monitor their condition three times - on the second day, one week and one month after vaccination, he said.
The drive to vaccinate young people was announced last month, following the example of China.
The ministry plans Pfizer shots for students aged 12-18 nationwide from Oct 4, starting with 29 provinces, including Bangkok, hit the hardest by the pandemic.
All schools must talk with students’ parents and get their approval, and send the list to education offices supervising their area by Sept 25.
The ministry plans to reopen all schools after students are inoculated.