This week, the Centers for Disease Control and Prevention (CDC) classified the so-called Delta variant of COVID-19 — B.1.617.2 — as a variant of concern. This is one of the variants behind India’s devastating outbreaks, and it has become the dominant strain in the United Kingdom.
Its shift from a variant of interest reflects the Delta variant’s higher transmissibility and the potential that the human immune system and antibody treatments are less effective against it.
The Delta variant is in Arizona. Through our partnership with TGen, whole genome sequencing has confirmed several dozen cases so far. We are working with TGen and several laboratories and public health partners, including the CDC, to monitor Delta and other variants.
All of this news is understandably concerning, but it requires some context.
The presence of the Delta variant provides yet another reason to get vaccinated against COVID-19 as soon as you can. Research suggests that vaccines are effective against the Delta variant — the Pfizer and Moderna vaccines have been found to be 88% effective at preventing serious illness after both doses, but only 33% effective after one dose. This highlights how important it is to be fully vaccinated.
Viruses typically change through mutation as they continue spreading, and new variants are expected to occur over time. New variants sometimes emerge and disappear. Other times, variants appear and linger. The U.K. variant (B.1.1.7, or Alpha variant), which also is more transmissible, has become the dominant strain in Arizona since the first cases here were confirmed in late January.
The Delta variant hasn’t proven any more harmful than the U.K. variant, but there’s still reason for those who haven’t been vaccinated to be concerned about it. According to Public Health England, early data suggests that Delta is 60% more transmissible and more likely to lead to hospitalization than Alpha. This data also suggests Pfizer and Moderna vaccines are highly effective in preventing hospitalization from the Delta variant. People continue to get seriously ill and die from COVID-19, which is tragic when there are safe, highly effective, and free vaccines widely available around the state.
Having as many people vaccinated as possible will reduce the transmission of COVID-19 and in the process reduce the development of variants like Delta. If you have yet to be vaccinated, I hope you’ll do so to protect yourself, your family, and your community.