The World Health Organisation (WHO) on Tuesday said that the primary analysis of data from the Phase-III trials of AstraZenca-Oxford University's COVID-19 vaccine shows that it offers protection against severe disease, hospitalisation and death.
It is important to determine the effectiveness of the vaccine in preventing more severe illness, the global health agency said in a tweet.
It also highlighted the need to reduce virus circulation and prevent infections so that it reduces the opportunities for coronavirus to mutate further as it can lead to a decrease in the efficacy of existing COVID-19 vaccines.
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On Sunday, the South African government announced to put on hold its COVID-19 vaccination programme for AstraZenca-Oxford University vaccine as data from a study showed that the vaccine provided minimal protection against mild-to-moderate infections caused by the coronavirus mutant, also called 501Y.V2, in the country.
However, the study did not say if the vaccine helped in preventing severe cases of the disease as it involved mostly young adults, who are not considered to be at high risk for serious cases.
In a media briefing on Monday, WHO Director-General Tedros Adhanom Ghebreyesus called the study's result a concerning news. However, he said it is important to determine if the vaccine is effective in preventing more severe illness.
"Given the limited sample size of the trial and the younger, healthier profile of the participants, it is important to determine whether or not the vaccine remains effective in preventing more severe illness," he said.
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Also read: AstraZeneca's COVID-19 vaccine shot put on hold over variant data