The total number of doses provided up to Wednesday stands at 3,691,591 with a rate of vaccine distribution of 37.32 doses per 100 people.
The Medicine and Healthcare products Regulatory Agency said it had approved the vaccine for adult booster doses "after it was found to meet the UK regulator's standards of safety, quality and effectiveness."
The jab, produced by Serum Institute of India under licence from the US-based Novavax, will now be distributed as part of global vaccine-sharing system Covax, "giving a much-needed boost to ongoing efforts to vaccinate more people in lower-income countries", WHO said in a statement.
"The Kingdom of Saudi Arabia has granted approval for entry of individuals vaccinated with the Russian Sputnik V vaccine starting from Jan.1, 2022," the Russian Direct Investment Fund (RDIF), which financed the development of Sputnik V, said in a statement.
The National Command and Operation Centre has allowed booster shots for people aged over 30 years because of the spread of the Omicron variant to over 100 countries, including Pakistan.
The health experts said that based on studies and research issued by the World Health Organisation (WHO), it indicates that people who received a booster dose were less infected than those who did not receive the booster dose even if they were exposed to mild symptoms.
"We have found that a sizable population of housewives are unvaccinated, and they socialise and attend weddings without face masks,” Qasim Siraj Soomro, parliamentary secretary health of the Sindh provincial government, said.
Pfizer and BioNTech said they have not fully reviewed the complaint, but expressed surprise over the litigation.
"Aside from being safe and also getting vaccinated, the kids can also enjoy the outdoors, the scenery, and the animals that are here inside," said Joyce Pablo, mother of one of the children being inoculated.