Popular science: why the delta strain spreads faster

Xinhua News Agency, Beijing, August 17th, Science Popularization: Why Delta Strain Spreads Faster

Xinhua News Agency reporter Feng Yujing

Since its first appearance in India at the end of 2020, the delta strain of the new crown mutant virus has swept India at an extremely fast rate and has become the main mutant strain circulating in most parts of the world
.

Current studies have found that the Delta strain has the characteristics of high viral load, fast virus replication, high incidence of "breakthrough infection", and high risk of reinfection
.

Researchers from the Guangdong Provincial Center for Disease Control and Prevention and other institutions in China published a preprinted paper on the Medical Papers Archive in July, stating that the average time from exposure to the virus to the first positive nucleic acid test results for people infected with the Delta strain is 4 days, while the average time of the original strain is 6 days, which indicates that the Delta strain replicates faster
.

The research team of Houston Methodist Hospital in the United States sequenced and recorded the mutant virus of almost all the new crown cases in the hospital system and found that since March 2021, about 17% of cases infected with the Delta strain have occurred in the vaccinated population In addition, the incidence of "breakthrough infection" of the Delta strain is almost three times that of all other mutant strains combined
.

According to statistics from the United Kingdom, about 1.
2% of the infected persons diagnosed in the UK from April 12 to June 27 this year may have been super-infected, and the risk of super-infection with the Delta strain is 1.
46 times that of the Alpha strain
.

An international research team led by the University of Wisconsin in the United States published a preprinted paper on the Medical Paper Archive on August 11, showing that people who have been vaccinated and infected with the Delta strain have the same amount of virus in their noses as they have not been vaccinated.
There are just as many people
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Researchers made similar findings in data from Provincetown, Massachusetts
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The preprint paper published by Singapore researchers at the end of July also showed that after tracking the daily viral load of vaccinated and unvaccinated infections, they found that in the first week of infection, the viruses of the two groups of Delta strains The capacity is similar
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Barnaby Young, a co-author of the paper and an infectious disease clinician at the National Center for Infectious Diseases in Singapore, said that in view of the high level of the virus in the first week after infection with the Delta strain, regardless of the vaccination status, measures such as wearing a mask and cleaning hands Can reduce transmission, which is important to everyone
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The British "Nature" magazine website published an article on the 12th of this month that these findings confirm the importance of protective measures, such as wearing a mask indoors to reduce transmission
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