WHO's Dr. Mike Ryan has said that we should not be too concerned about an increase of symptom severity among the new strains of Covid-19.
"The viruses can become more infectious but they rarely become more severe, because it's not in their evolutionary interest." Dr. Ryan said.
"Right now, as far as we can see, the data s pointing to these vaccines still being effective, and we're not overly concerned that that is going to change.
"Even if there was a change in that, it is relatively straightforward to tweak the vaccines."