Japan’s fifth wave of Covid-19 has virtually disappeared so dramatically that some scientists are puzzled as to why it happened. One team suggests the highly infectious Delta strain mutated into extinction on the island nation.
In mid-August, Japan experienced a peak in Covid-19 infections, recording over 23,000 new cases per day. Now the metric is just around 170, with deaths attributed to the disease mostly remaining in single digits this month.
The decline has been attributed by many to high vaccination rates, public acceptance of masks, and other factors, but some researchers say the drop was uniquely significant, compared to other nations with similar conditions.
Ituro Inoue, a geneticist at the National Institute of Genetics, believes that Japan had the good fortune of witnessing the Delta strain mostly rooting out other variants of the SARS-CoV-2 virus before then eradicating itself. He explained his team’s theory to the Japan Times newspaper this week.
For some time now, Inoue and his fellow scientists were researching mutations of SARS-CoV-2 and how they are affected by the protein nsp14, which is crucial for the reproduction of the virus.
RNA viruses, like the one causing Covid-19, tend to have a very high mutation rate, which helps them quickly adapt to changes in the environment. However, this opens the door for a so-called “error catastrophe,” when bad mutations pile up and finally cause the full extinction of a strain. The protein nsp14 appears to offer a form of error proofreading that helps the virus genome to stay below the threshold of the “error catastrophe.”
In the case of Japan’s fifth wave of Covid-19, the Delta variant’s nsp14 failed at this job, Inoue believes, based on the genetic study of specimens collected from June to October. Contrary to his team’s expectations, there was a lack of genetic diversity, while many samples had many genetic changes in the site called A394V, which is linked to the error-fixing protein.
“We were literally shocked to see the findings,” the researcher told the Japan Times. “The Delta variant in Japan was highly transmissible and [was] keeping other variants out. But as the mutations piled up, we believe it eventually became a faulty virus and it was unable to make copies of itself.”
The theory could be relevant to the previous SARS strain, which was identified in 2003, explaining why it didn’t cause a pandemic. But that would be hard to confirm, since the outbreak ended relatively quickly and didn’t result in the massive collection of genetic data necessary to test the hypothesis.
It’s not clear why Japan had this lucky turn of events, but nothing comparable happened in other East Asian countries like South Korea, where populations are genetically close to that of Japan. Virus mutations similar to those flagged by the scientists have been discovered in at least 24 countries, Inoue said. He and his team plan to publish a paper detailing their findings by the end of November.
Even if the natural extinction theory is confirmed, it is at best a temporary reprieve for the Japanese people. New, more successful strains are likely to eventually find their way into the country, though quarantine measures and immigration control could delay the emergence of new variants in Japan, Inoue believes.
Meanwhile, Tokyo is bracing for a new wave of Covid-19 this winter and is preparing to live with the virus. The government reportedly plans to ease travel restrictions by increasing the number of people it allows to enter the country per day from 3,500 to 5,000.
Controversial agriculture laws that saw farmers across India protesting for over a year are going to be rolled back, Prime Minister Narendra Modi has unexpectedly announced.
“I want to tell the country that we have decided to repeal the three farm laws,” Modi said in a televised address on Friday, which local media described as “stunning.”
The Indian parliament will complete the constitutional process of repealing the agricultural legislation in late November, he added.
However, the PM again defended the divisive legislation, saying that the reform of the sector, which accounts for some 15% of India’s $2.7 trillion economy, was actually aimed at supporting the country’s small farmers.
Whatever I did was for farmers. What I am doing is for the country.
“Maybe something was lacking in our efforts, which is why we couldn’t convince some farmers about the laws,” Modi acknowledged.
The laws, which were introduced last September, allowed farmers to sell their crops outside of the government-regulated wholesale markets, in which they were guaranteed a minimum price.
The government argued that it would see them earning more, but growers feared that that move would, on the contrary, cause a drop in prices and make them hostages to large corporations.
Thousands of farmers joined the protests against what they called “black laws,” and some rallies turned violent. A year later, many demonstrators remain camped along roads outside the capital New Delhi.
And the farmers aren’t planning on going home just yet, with one of their leaders saying on Twitter: “We will wait for parliament to repeal the laws.”
Modi’s concession to the protesters may have been unexpected, but it comes several months ahead of elections in India’s most populous state of Uttar Pradesh, as well as two other northern states with large rural populations.
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