The Delta Variant has overtaken Japan.

The COVID-19 variant is already widespread across the globe and has become the main variant in Japan, replacing the original one.

Japan’s National Institute of Infectious Diseases studied the prevalence of the L452R mutation, predominant in Delta, among recent cases and found out the extent to which it is dominating the current wave:

At a staggering rate of 98%, nearly all recent infections in Tokyo and surrounding prefectures were caused by viruses with the Delta mutation. Furthermore, different parts such as Osaka, Hyogo, Okinawa, and Kyoto prefectures saw high rates fluctuating between 92% and 99%.

Delta Variant

The Delta variant is far more infectious than Alpha and the original virus. Studies have concluded that it has twice the infectious capability of the original, and 1.5 times that of the Alpha variant.

Moreover, the WHO disclosed that people infected with Delta had a viral load –i.e. the potential to infect others- 1,200 times that of those with the original. 

Delta Symptoms 

No clear-cut answer has been given about the extent of the Delta variant’s symptoms seriousness in comparison to its predecessors, yet the WHO confirmed that hospitalization rates are rising.

A study by the University of Toronto found that Delta carries 3.34 times more risk of ICU admission while the hospitalization rate, in general, is 2.08 times more than that of the original virus.

Vaccine Efficiency

Previously, the WHO released lab studies that indicated that vaccines produce fewer antibodies against the Delta variant while stressing that vaccine efficiency hasn’t lowered.

A study published in the New England Journal of Medicine found that the first dose of the Pfizer vaccine had a 35.6% effectiveness in preventing Delta symptoms, and 88% with the second. In comparison, the first dose of AstraZeneca had a 30% effectiveness, and 67% with the second.

The general consensus seems to be that two vaccine doses are highly efficacious against the Delta variant.