A study conducted by Pfizer and BioNTech laboratories, whose results were published last Thursday, confirmed that a third dose of their vaccine against Covid-19 is 95.6 per cent effective in combating symptomatic disease.

In a trial with 10,000 participants who had completed a two-shot Pfizer regimen, half were randomised to receive a further equal-strength dose of the shot, and half a placebo. Five cases of Covid were registered in patients receiving the booster compared with 109 who were given a placebo.

“Based on these findings, we believe that, in addition to broad global access to vaccines for everyone, booster vaccinations could play an important role in sustaining pandemic containment and a return to normalcy’’, said Ugur Sahin, the head of BioNTech.

Commenting on this, Dr Zakaria al Balushi, Infectious Disease Consultant at Royal Hospital, said that recommendations for taking the third dose (booster) were based on studies of the immune response and the weakness of antibodies.

“Yet, there is no clinical study at the time that compares the two doses with three doses in terms of infections”, he added.

Dr Zaid al Hinai, Assistant Professor, College of Medicine, and Infectious Diseases Consultant at Sultan Qaboos University Hospital, said that the booster dose of corona vaccine had proven effective after six months of the second dose, especially for groups at risk of the disease, such as the elderly.

“The application of this “three-way strategy” helps reduce the increase in infections and hospitalisations and intensive care unit patients’’, he recommended.

While mutants of the emerging virus occupy the whole world, Britain has revealed that it is “closely following” the spread of a new sub-mutant of corona in the light of the high number of infections in the country. It has not yet been determined whether it is more contagious.