51�Թ�

They found that very few people had developed any antibodies unique to omicron, a pattern indicative of strong imprinting by the initial vaccination.

It also reduced viral loads in those infected by the alpha, delta or omicron coronavirus variants that caused distinct COVID-19 waves over the three years of the pandemic.

The highest detection frequency over the study period aligned with Las Vegas' first wave of omicron variant infections, as confirmed through parallel testing at a local wastewater treatment plant.

This decline was evident among those infected in the early phase of the pandemic and those infected when the delta and omicron variants were dominant.

That single-target vaccine replaced combination shots that had been targeting both the original coronavirus strain and a much earlier omicron version.