An epidemiologist today said a booster dose of Covid-19 vaccine may be needed to improve effectiveness and offer protection against variants of the virus which have cropped up over the past year.
Dr Andrew Kiyu Dawie Usop, chairman of the Sarawak Covid-19 Vaccine Advisory Group, said additional doses may be needed as some of the vaccines might not be enough to curb more contagious variants such as the South African (B.135), UK (B.117) and Brazilian (P.1) variants.
“The effectiveness of the vaccine is not because of the efficacy of the vaccine,” he said at a talk organised by the Sarawak Development Institute on the state vaccination campaign in Kuching.
“It is because of the mutations of the virus. Some of these variants are more infectious.”
He added that the efficacy of the current vaccines vary against these variants.
“For example, the Pfizer vaccine has the same efficacy with the UK variant while the South African variant is more efficacious and reduces antibody levels in the body.”
He said some vaccines might not be effective enough to substantially reduce the rate of transmission or serious disease, adding that factors such as the variants and compliance with non-pharmaceutical intervention measures must be taken into consideration.
“Efficacy of the vaccine is what was measured during clinical trials. Effectiveness, this requires constant follow-up with people who have been vaccinated.”
He said this was also the case for flu vaccines, where annual jabs are required.