Jinan, capital of East China's Shandong province began offering COVID-19 booster shots to people over 18 on Oct 13, according to the Jinan Center for Disease Control and Prevention.

According to domestic and foreign research, COVID-19 vaccines have played a major role in preventing infections and alleviating symptoms.

However, the efficacy of vaccines wanes after some time. Research has proven that booster shots can quickly increase the amount of neutralizing antibodies without causing serious side effects, experts said.

The booster shots will be available across the region for adults who have been fully vaccinated for at least six months.

Key groups will be prioritized during the initial stage, including people at higher risk of contracting the disease, such as workers in the cold chain, customs, transportation and health services sectors, as well as those who plan to travel abroad.

People intending to get an additional shot will be given the same vaccine made by the same company. If there is a shortage of a particular vaccine, other vaccines of the same type but from a different company can be used as an alternative, local authorities said.

Residents must produce their identify cards at the vaccination sites and remain on site for at least 30 minutes after the vaccination for monitoring.