Scientists at Harvard University have found that the delta strain can cause a severe pandemic -2, similar to the delta variant, are characterized by increased transmission and the ability to infect people who have had previous infections or have been vaccinated. According to the researchers, who published a scientific paper in the journal Cell, the delta variant could cause a more severe wave of pandemic with more breakthrough infections occurring in vaccinated.
Experts have created a mathematical model that describes how pandemics are caused by hypothetical options will affect populations using different combinations of prevention measures: wearing masks, social distancing and vaccination.
The model reveals the course of the SARS-CoV-2 pandemic caused by various hypothetical coronavirus variants, including combinations of several symptoms: increased transmissibility (similar to alpha), partial escape from the immune system (similar to beta), and improved transmissibility with partial escape as in delta. For each of the scenarios, the researchers analyzed the total number of infections and the percentage of infections prevented by vaccination.
It turned out that the variant with increased transmissibility is likely to be more dangerous than the variant that can partially elude the immune system. However, a variant with both signs can cause more infections, re-infections, and breakthrough infections than a variant with only one sign. According to the model, vaccination would prevent more cases that a more transmissible virus could potentially cause, and the milder nature of breakthrough infections should significantly reduce overall mortality.