The highly contagious Delta variant is now the dominant Covid-19 strain in the U.S., comprising an estimated 51.7% of new cases over the two weeks ended July 3, according to the Centers for Disease Control and Prevention. The variant first identified in India has been doubling in prevalence about every two weeks in the U.S. and has been detected in at least 104 countries, CNBC reported. The Alpha variant discovered in the U.K., which had been the dominant U.S. strain, now makes up 28.7% of new cases, and the Gamma variant first found in Brazil makes up 8.9% of cases, according to CDC estimates. The World Health Organization expects the Delta variant, believed to be about 55% more transmissible than the Alpha variant, to become the dominant strain worldwide. Although the U.S. will have fully vaccinated about 160 million Americans later this week, vaccination rates in about 1,000 counties are still below 30%, primarily in the Southeast and Midwest, CDC Director Dr. Rochelle Walensky said last week. The Delta variant is driving increases in some of those counties, including parts of Missouri and Wyoming. “I think there are two Americas,” said Dr. Paul Offit, a pediatrician who has served on advisory panels for the CDC and the Food and Drug Administration. “There is the vaccinated America and the unvaccinated America, and I think the unvaccinated America is about to pay a price for that.”
The kids are (not) alright: Europe sounds the alarm as Delta variant soars among teens and 20-somethings
Just as England prepares to lift social distancing rules, make mask use voluntary, and cut travel quarantine requirements, a surge in cases in Spain and Portugal—prime vacation destinations for English and other European travelers—is pushing back against Europe’s great reopening.
The question now facing European governments is whether enough of their adult population is protected to keep a spike among youth from having deadly consequences.
As they decide whether to reintroduce restrictions or let the new wave run its course, many in healthcare look on in dismay.
France currently allows people to travel to all other EU members as long as they are fully vaccinated or present a negative PCR or antigen test on their return.
“For those who have not yet booked their holidays, avoid Spain and Portugal as a destination,” he told France 2 television. “It’s better to remain in France or go to other countries.”
Beaune added that France, which fears being hit by a fourth wave of coronavirus infections this summer, was weighing restrictions on travel in Europe over the spread of the highly infectious Delta mutation.
Delta is highly transmissible—about 60% more so than the previously dominant Alpha, which was itself more transmissible than the original virus—and more virulent.
Delta’s higher transmissibility means it can infect people before we get to offer them protection with vaccines—and the vast majority of the world has not yet been vaccinated. It appears that, in comparison with the previously dominant virus, Delta produces higher viral loads earlier in infection, which may mean that it’s even more infectious during the period when people don’t yet realize they’re infected. It also appears that Delta is more able to cause so-called breakthrough infections in vaccinated people, although, fortunately, the resulting infections are comparatively mild.
Delta’s greater virulence means that unvaccinated people who become infected will be sicker and the burden on the health care system will be greater. Evidence suggests, for example, that an unvaccinated person with Delta infection is roughly twice as likely to require hospital treatment than a person infected with the previously dominant variant.
In the U.S., the communities most at risk are those that are undervaccinated, predominantly in the South. Unfortunately, those communities also tend to be the ones with high rates of comorbidities, such as obesity and diabetes, which are likely to render folks more vulnerable. We should also remember that people who are unvaccinated may also be struggling with vaccine access and work in jobs that place them at higher risk of infection.