Source: United States & Canada – South China Morning PostModerna on Thursday said its Covid-19 vaccine shot was about 93 per cent effective four to six months after the second dose, showing hardly any change from the 94 per cent efficacy reported in its original clinical trial.That compares favourably to data released last week by rivals Pfizer and BioNTech, in which they suggested their vaccine’s efficacy waned around 6 per cent every two months, declining to around 84 per cent six months after the second shot.Both the Moderna and Pfizer-BioNTech…Read More