The Centers for Disease Control and Prevention reported this week the original strain of SARS-CoV2, the virus that causes COVID-19, is no longer detected among variants circulating throughout the country, and variants are now responsible for all cases in the United States.
The CDC says the Delta variant is now the predominant variant in the U.S, making up an estimated 83.2% of recent cases.
In Indiana, the Delta variant is the dominant strain; it has been detected in 76.6% of samples, an increase of 41.5% from June, according to ISDH data.
ISDH says variants are identified through sequencing, where states submit randomized samples for variant testing to see which strain of the virus is present.
“Not all samples need to be tested to get a good picture of which variants are present and how they are changing over time, and this saves resources,” ISDH said. “The Indiana Department of Health works in partnership with other laboratories in Indiana to test a subset of positive samples from different areas of the state.”
There are three classifications of variants: variant of interest, variant of concern and variant of high consequence. As of July 20, the CDC’s website says there are no variants of high consequence, but the alpha, beta, delta and gamma variants are all variants of concern in the United States. Variants of concern have evidence of an increase in transmissibility or more severe disease.
Data from ISDH shows the alpha, delta and gamma variants have all been found in Indiana, but as of July 23, the delta variant is the only variant of concern.
The CDC also says COVID-19 is now a preventable disease and that the vaccines are effective against variants, including the Delta variant.
“The best way to prevent the spread of COVID-19 variants is to prevent the spread of disease, and vaccination is the most powerful tool we have,” CDC director Dr. Rochelle Walensky said.
For coronavirus vaccine information in Indiana, click here.