The 60,000 vaccine doses arrived in Goma, capital of North Kivu province on a cargo plane from Kinshasa on Thursday.
North Kivu has recorded the highest number of coronavirus infections after the Democratic Republic of Congo's capital.
"Covid is endemic, we will live with covid-19. So to protect ourselves we have the vaccine which is one of the means of protection," said Eugène Nzanzu, the provincial health minister.
"It is therefore important to receive it and to follow the instructions that come from the authorities and not to follow everything that is said on social media because it is a vaccine that is administered elsewhere and we are administering it in Kinshasa since Monday," he added.
Congo launched its COVID-19 vaccination campaign on Monday after a more than one-month delay because of concerns about the AstraZeneca vaccine's safety.
In Goma, a city of over 1.5 million people, inoculations are due to begin on May 1. But authorities face a hesitant public.
"It is a vaccine that has proven its effectiveness, certainly there have been a few people who have developed what is called a thrombosis, but it is one person in 1 million," said Jean Ludovic Maternier, the head of UNICEF's operations in eastern DRC as he sought to address concerns about the vaccine.
"There is a bigger risk of seeing a car accident while going to get vaccinated than to see a problem related to the vaccine itself," he said.
In Goma, vaccine skepticism is high. Conspiracy theories, a lack of trust in the government, and misinformation are rife.
"I would like to tell you that the head of state did not get the vaccine, that's why I also do not want to take it.... They are corrupt, they want us to be the ones to take the vaccine so that the youth and our children are victims," charged Fify Nyamwema, a shopkeeper in Goma.
"I personally do not want to take this because I know that covid-19 does not exist," said Kakule Rodrigue as he walked to his workplace.
North Kivu is also home to several armed groups who pose a threat to the vaccination efforts.
By Thursday, only 252 people had been vaccinated in the Congolese capital, home to over 10 million people.
The country has reported nearly 30,000 cases and 752 deaths.
_Reporting by Gael Mpoyo in Goma, eastern DR Congo _