Countries across the globe brace for hard-hitting Delta variant as concerns grow

COUNTRIES around the world are bracing for the effects of the rapidly spreading Covid-19 Delta variant.

First encountered in India in October 2020, Delta (B.1.617.2), now reported in 85 countries globally, continues to be seen in new countries across all WHO Regions, 11 of which were recorded in the past two weeks.

According to the WHO’s latest situational report, a study from Singapore showed that infection with the Delta variant was associated with higher odds of oxygen requirement, intensive care unit (ICU) admission, or death.

A study in Japan estimating the relative instantaneous reproductive number (a measure of transmission at a specific point in time) showed that the Delta variant was associated with greater transmissibility when compared to the Alpha variant – detected in the UK in September, and estimated to be 40-80% more transmissible.

Overall, Delta was associated with 1.23 times higher transmissibility than Alpha.

Other studies found vaccine effectiveness (VE) against Delta, while slightly reduced, was maintained at 88% for Pfizer BioNTech-Comirnaty and 67% for AstraZeneca-Vaxzevria.

“Together, these studies suggest moderately reduced VE at preventing symptomatic disease and infection due to the Delta variant. No such reduction in VE was observed for hospitalisation in the UK study for either vaccines.

“The studies also provide further evidence of the importance of two doses of both Pfizer BioNTech-Comirnaty and AstraZeneca-Vaxzevria in preventing hospitalisation, symptomatic disease and infection due to both Delta and Alpha variants,” the report notes.

Answering questions during a WHO briefing on Friday regarding reports in Australia that it takes anywhere between five to 10 seconds of exposure to the Delta variant to transmit it versus 10 to 15 minutes of exposure to transmit other types of variants, WHO technical lead for Covid-19, Dr Maria Van Kerkhove, said studies were under way.

“In terms of how this virus transmits between people, we know that it is mainly between close contact and there are infectious particles that travel from an infected person to another. These can be larger droplets or smaller aerosols.

“In terms of the Delta variant, there are a lot of studies that are under way. We haven’t seen any difference in the duration of infectiousness, meaning how long somebody can pass the virus to another person. There are some studies that also look at CCTV, that actually follow individuals and track them over time to see when infection occurred.”

WHO director-general Dr Tedros Adhanom Ghebreyesus said globally there is currently a lot of concern about the Delta variant and WHO is concerned about it too.

“New variants are expected and will continue to be reported. That’s what viruses do, they evolve, but we can prevent the emergence of variants by preventing transmission.

“It’s quite simple. More transmission, more variants. Less transmission, less variants.”