Dhaka, Dec 7 : The Bangladesh government announced that everyone aged 60 or above will be offered a fourth dose of Covid-19 vaccine in order to boost people's fading immunity against the disease. Speaking at a press conference, Ahmedul Kabir, a senior official of the Directorate General of Health Services (DGHS), announced that the fourth shot will be available at seven vaccination centres in Dhaka on December 20 on a trial basis, reports Xinhua news agency. Subsequently, he said the campaign will be expanded to inoculate people above the age of 60, frontline workers and those suffering from comorbidities. According to the official, Bangladesh aims to provide the fourth vaccine shot to over 20 million people. More than 126 million people have so far received at least two doses of Covid-19 vaccines in the country, while over 62 million people have received booster shots. Bangladesh has been using Covid-19 vaccines developed by AstraZeneca, Sinopharm, Moderna, Pfizer, Sinovac, and Johnson and Johnson. Bangladesh began its Covid-19 vaccination drive in January last year to contain the pandemic. /IANS