Are the vaccines driving the delta variant?
I propose a hypothesis about the correlations among the trends of recent COVID infection rate, the change of COVID virus variants, and the mass vaccination campaign. According to Geert Vanden Bossche's opinion, "[d]eployment of current Covid-19 vaccines in mass vaccination campaigns combined with the ongoing widespread circulation of Sars-CoV-2 can only increase immune selective pressure on Sars-CoV-2 spike protein and hence, further drive its adaptive evolution to circumvent vaccine-induced humoral immunity." While that statement does not find agreement from the authorities, the CDC's data provided some clues that indicate that what Bossche said on June 21, 2021, could be true.
Below are three diagrams copied from the CDC websites. Graphic 1 shows the change of COVID virus variants, from the week ending June 5, 2021, to September 4, 2021, which is an estimate made by Nowcast. On the farthest left side, the percentage of alpha variant is about 55.7%, delta variant 14.1%, the rest are other variants. (Alpha variant was 69.6%, delta variant 2.4% on May 15, 2021, when I started to capture the data.) The percentages of variants have been changing: delta variant becomes the most predominant, while alpha variant is disappearing. As estimated, the delta variant is now at 98.9%. What's behind this change?
Let's take a look at the U.S. vaccination rate diagram, Graphic 2. Around June 5, 2021, the number of people who had received at least one dose of the COVID vaccines is around 175 million. As mentioned early here, the alpha variant was still the dominant one. Since the vaccines are quite effective against the alpha variant, its dominance was disappearing. On July 3, 2021, the Alpha variant was only 15.8% among the newly infected people. The delta variant was 68.7%. They switched their positions within a month. By that time, the number of people who had received at least one dose of the COVID vaccines was around 182 million, about a 4% increase from June 5. This suggests the effectiveness of the vaccines against the alpha variant but not the delta variant. This trend continues through July 31, when the delta variant constitutes about 96% of new cases. Is this just a coincidence or a correlation?
Now we can take a look at the U.S. Daily Trends in Number of COVID-19 Cases, Figure 3. Before June 6, 2021, the number of daily cases had been declining since mid-January. There are different opinions about why it declined. On the diagram, we can see that the declining trend continued until July 5, 2021, when the daily cases started to trend higher. As we know now, that's when the delta variant became the dominant one. As of September, the daily new cases seem to be at the peak, a similar situation to what we had in January 2021.
If there was no mass-vaccination campaign started early this year, the alpha variant would still be the dominant one today. My hypothesis is a supplement to G.V. Bossche's claim that "the ongoing mass vaccination experiment drives a rapid evolutionary response of SARS-CoV-2." What the government should do now is stop the mass vaccination campaign. Otherwise, a new variant will come out, and we are going to have another cycle of mass infections. And the current vaccines will be useless.
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