Sri Lanka's health authorities have begun administering third doses of the COVID-19 vaccine on people aged 60 and above in the South Asian country.

The booster dose administration started on Wednesday in Western and Southern Provinces and the Anuradhapura and Ampara Districts.

Doctors on the ground told Xinhua that the Pfizer vaccine is used as the booster dose, and that all people in the cited age group can visit their nearby vaccination centers with their vaccine cards to take the third shot, regardless of whatever vaccine they received as the first or second dose.

The first and second doses administered in Sri Lanka were the Sinopharm, Sputnik V, Moderna, Pfizer and AstraZeneca vaccines.

Health officials said people over 60 are eligible for the booster dose if it has been three months since they received the second dose.

Officials also called on people not to queue up at vaccination centers but to await a digital message to be sent to them stating the vaccination time.

According to health authorities, the third dose rollout in the country started earlier with frontline health workers including security forces personnel, with over 120,000 people having so far received the booster dose.

According to official statistics, 93.5 percent of the population over 20 years of age in Sri Lanka have received two doses to date.

The country has so far reported over 552,000 confirmed cases of COVID-19, with over 14,000 deaths.