How contagious are the variants? How contagious are the variants?
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How contagious are the variants?

    This is part 88 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.

    Are the variants more contagious?

    The WHO has strengthened its international monitoring system as it tracks the spread of three coronavirus variants that contain a particular mutation: N501Y. The mutation affects the notable spike proteins on the surface of the particle and increases the infectious capacity of the virus. The variants emerged from the UK, South Africa, and Brazil.

    UK variant

    The variant originally confirmed in the UK was first identified in September of 2020. According to WHO data, it is 43 to 90 percent more contagious than the original virus. The WHO also says that analysis shows the variant’s effective reproduction number — the average number of people a single carrier will infect — is likely to be 41 percent higher than that of the original virus. Japan’s National Institute of Infectious Diseases puts the figure at 32 percent.

    The WHO says the variant has been found in 132 countries and regions as of April 13.

    South Africa variant

    This strain is believed to have emerged in early August of last year. An analysis of South African coronavirus cases conducted in mid-November of last year showed that the majority of infections at that time were of the variant.

    The WHO says this strain is 50 percent more infectious than the original virus. It also says the effective reproduction number is likely to be 36 percent higher. As of April 13, the body had confirmed the variant in 82 countries and regions.

    The variant also has a mutation known as E484K which allows it to evade antibodies and could lead to an increased risk of reinfection.

    Brazil variant

    This variant was identified on January 6 during an airport quarantine check in Japan for people arriving from Brazil. Researchers believe it emerged the previous month in the northern city of Manaus. As of last month, 73 percent of infections in the city were cases of the variant.

    The WHO says the effective reproduction number is likely to be 11 percent higher than the original virus. As of April 13, it had been confirmed in 52 countries and regions. It also has the E484K mutation found in the South Africa variant.

    This information is accurate as of April 21, 2021.

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