As COVID-19 spreads from person to person, it changes – evolving over time to become more and less like the original virus. When these changes are significant, they’re called “variants.” Scientists can identify new strains of coronavirus by mapping their DNA, and each one gets a name based on letters in the Greek alphabet. So far, we’ve seen alpha, beta, delta, and omicron variants – and each has its own impact on the pandemic.
Variants are often difficult to distinguish from each other, but they can be tracked through a process known as “sequencing.” Sequence data from contributing wastewater treatment plants, which show proportions of variants in each week’s sample, is used nationally to categorize circulating COVID-19 lineages as “Variants Under Monitoring,” “Variants of Interest,” and “Variants of Concern.”
NB.1.8.1 is an example of a variant that’s under monitoring. It has four mutations in its spike protein – including N501Y, E484K, and K417N – that may make it more likely to transmit, and less vulnerable to neutralization by convalescent serum and monoclonal antibodies. Virological studies also suggest it has high infectivity in lab-grown cells and strong infectivity in people.
It’s too soon to know if these particular mutations will impact vaccination efficacy against COVID-19, but previous research suggests vaccines are working well to protect against serious illness and hospitalization. As we continue to monitor the COVID-19 outbreak, a key goal will be to select a vaccine formulation for fall 2024 that matches circulating variants as closely as possible.
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