yes. genomic surveillance makes it possible to measure the presence of various strains in various areas and their ongoing mutations.

Yes. India.

India [0], and with > 1B people there, that's a whole lot of opportunities to mutate, and a whole lot of jabs to manufacture, distribute, and perform. In the case of mRNA vaccines, they need to be kept quite cold until basically day of use. India is poor and hot, it's non-trivial to say the least.

As others have said, this isn't primarily a US problem; 30.7% of the world population has received at least one dose of a COVID-19 vaccine, and 16% is fully vaccinated [1]. Even if 100% of the US population were vaccinated, it'd barely move those figures.

[0] https://www.thequint.com/coronavirus/covid-variants-found-in...

[1] https://ourworldindata.org/covid-vaccinations