The Infection Rate of COVID Variants Continues To Expand
July 16, 2022 (EIRNS)—Summary of COVID Variants from July 4: Writes University of South Australia Professor of Biostatistics and Epidemiology Adrian Esterman on July 4 for “The Conversation”: “Australia is heading for its third Omicron wave in the coming weeks, as BA.4 and BA.5 become the dominant COVID strains.
“BA.4 and BA.5 are more infectious than previous COVID variants and subvariants, and are better able to evade immunity from vaccines and previous infections. So we’re likely to see a rise in case numbers. So what are BA.4 and BA.5? And what can we expect in this next phase of the pandemic?”
Esterman supplied calculations, which are apparently based upon the laboratory studies of the variants, and then extrapolated to derive the R0 number used. Original Wuhan strain’s R-naught value (R0) was around 3.3—that is, 3.3 people are infected by each infected person. Delta was up at 5.1. BA.1 (Omicron) at 9.5.
BA.2 (Stealth Omicron) was 1.4 more than BA.1, or 13.3. Then, BA.4/5 (with the same genetic change at its base). It may be 1.4 more transmissible than BA.2, or up to 18—in the category of measles. However, the latest is BA.2.75 (Centaurus) with some likelihood of continuing the trend of increasing transmissibility.
A May 26 pre-print publication (a publication that has not yet been peer-reviewed) from a Japanese research group found that in lab-based, cell-culture experiments, BA.4/5 was able to replicate more efficiently in the lungs than BA.2. In hamster experiments, it developed into a more serious illness. However, data from South Africa and the U.K. found that their BA.4/5 wave didn’t see a major increase in severe disease and death, possibly because of the high rates of immunity due to previous infections.
The crude, larger picture is that the mutational activity of the COVID-19, allowing time and space, has rewarded variations that transmit faster. The practical “compromise” with COVID has resulted in pools of mutational activity that made the situation worse over time—and this situation could easily get much more virulent, conjoined to the increase of malnutrition and decrease in overall immune systems.