(CNN)The US reached another sobering milestone in the Covid-19 pandemic, with 600,000 lives lost to the disease as of Tuesday, according to Johns Hopkins University data.
While daily deaths have decreased over the months, hundreds of Americans are still dying every day from the disease that can be prevented from vaccines.
Over the past week, the average number of Covid-19 deaths each day was 343, according to data Monday from Johns Hopkins.
That’s about five times higher than the average daily number of people killed in car crashes.
As coronavirus keeps spreading across the globe, it has mutated into more transmissible strains — including the Alpha (B.1.1.7) and Delta (B.1.617.2) variants.
Both strains are now considered “variants of concern” by the US Centers for Disease Control and Prevention.
That means there’s “evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures,” the CDC says.
The Alpha variant has become the dominant strain in the United States. But cases of the Delta variant are rising.
Recent studies suggest the Delta variant isn’t just more contagious — it can also cause more severe illness than the Alpha variant.
A study from Scotland published Monday found the Delta variant was associated with about double the risk of hospitalization compared with the Alpha variant.
Getting vaccinated can stave off those variants. But experts say it’s critical to get vaccinated as soon as possible — before the virus mutates into more concerning strains.
“I’m extremely worried because the Delta variant is so aggressive in terms of transmission,” said Dr. Peter Hotez, director of the Texas Children’s Hospital Center for Vaccine Development.
“If we remember when we first talked about the UK variant — the B.1.1.7 variant across the British Isles that started out of southeast England — we were horrified about how aggressive it was infecting people. It was a much higher level of transmission,” Hotez said Tuesday.