Are coronavirus vaccines effective against variants? Are coronavirus vaccines effective against variants?
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Are coronavirus vaccines effective against variants?

    This is part 100 of our coronavirus FAQ. Click here to read other installments: #Coronavirus the facts. Find the latest information and answers from experts on everything COVID-19.

    90% effective against variants

    A Japanese study involving the Pfizer-BioNTech vaccine found evidence suggesting that it is effective against variants. The researchers studied more than 100 people who had received two doses of the vaccine. They found that 89 percent of the subjects developed antibodies thought to be effective against the seven main known variants.

    The study was carried out at Yokohama City University. A research team examined blood samples from 105 healthcare workers who received two doses of the Pfizer vaccine between March and April.

    Rates by each variant

    The team found that after the second dose, 94 percent of the subjects had sufficient antibodies considered effective against the Alpha variant; 90 percent against the Beta variant; 94 percent against the Gamma variant; 97 percent against the Delta variant; and 99 percent against the original strain.

    Graph: Efficacy of Pfizer-BioNTech vaccine

    The researchers report there is far less efficacy after just one dose of vaccine. After one shot, only 18 percent of the subjects had enough antibody to be effective against the Alpha variant; 21 percent against the Beta variant; 16 percent against the Gamma variant; 37 percent against the Delta variant; and 57 percent against the original strain.

    Professor Yamanaka Takeharu, who heads the team, says the next stage is to conduct the study on a larger sample group.

    This article was accurate as of June 11, 2021.

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