Has SARS-CoV-2 reached peak fitness?

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Has SARS-CoV-2 reached peak fitness?

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• A world first: Mankind is tracking the evolution of a virus as it happens, almost in real time, which is unprecedented. Scientific tools are giving molecular-level insights into how the virus and host interactions are playing out.
• How it started: The novel coronavirus genome was seen to have plasticity, in early 2020, that gave it an advantage. Transmissibility went up, and the D614G mutation arose fast (from parent virus) with 20% higher infectiousness. It globally dominated. 

1. The next transmissibility jump (50%) was in late 2020 with B.1.1.7 variant
2. The B.1.617.2 "India" variant is now prominent in many countries, though magnitude is uncertain, and it surely represents a jump from D614G and even B.1.1.7

• Evading immune system: The variants are now evolving to fool the human immune system too, with B.1.351 leading the show (although cannot escape vaccine-induced protection). The P.1 also does it well, but D614G and B.1.1.7 are not good at it. However, B.1.617.2 combines features of both - higher transmissibility and immune evasion. Some of that immune evasion is due to mutations that change the N-terminal domain (and not spike protein's RBD where early alterations had happened).
• What the virus is doing: It shows the virus is moving towards higher fitness, and natural selection is preferring mutations (and variants) that allow more transmission by immune sidestepping even if repeat infections have to happen! But virus will prefer great transmissibility and not lethality to be more fit and viable.
• More fit variants: So the newer, fitter variants will now evolve and will be monitored for public threat, but can it be an indefinite process? Nature has no infinity, and "maximum transmission" will arrive soon. The later variants won't add much. The stabilized final virus variant will be the dominant strain, with minium variations.
• Homological prediction: Scientifically it can be said that same must have happened when badly contagious RNA measles virus entered human society, and the virus was less stable and transmissible than it is now. 

1. Same is seen for viruses causing hepatitis A, poliomyelitis, mumps, and rubella. 
2. These viruses are unable to dodge the recovered host's immune response (perhaps there's no advantage in doing that at all as they have moved on to other hosts already)
3. [Evolutionary theory predicts that related organisms will share similarities that are derived from common ancestors - homologies]

• Huge shock to natural evolution: The rapid vaccine development by man has given a huge shock to SAR-CoV-2 virus's natural evolution. Vaccines are producing immunity stronger than mere infection-and-recovery is. Vaccines are stopping replication and hence, transmission; so virus will try to mutate into variants that escape this immunity itself. So the highly vaccinated societies (Israel, US) must see dangerous new mutants (virus has no other choice), but this is not happening. So, optimism is warranted!
• Is the game over: Some experts are predicting a complete resistance to present-day vaccines, by the virus, soon in future. Hence, keep an eye out on "vaccine-piercing" variants and update vaccines quickly then. So it's now crucial to ensure that what developed countries did (are doing) is done in developing ones also, in socio-sanitary settings.
• Summary: Give free or nearly free vaccines to everyone. The best selfishness today is being generous.

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