US hits COVID-19 milestone but experts fear holiday travel surge

More than 1 million people in the US have received the first dose of COVID-19 vaccine, the CDC has confirmed, though there are rising concerns that surging cases across the country will still outpace treatment. As of December 23, total coronavirus cases in the US had exceeded 18 million, with the virus now blamed for more than 321,000 deaths. More than 1.5 million new cases were recorded in the last 7 days.

In contrast, the CDC says that while almost 9.5 million doses of COVID-19 vaccine have been shipped through the US, only a little over 1 million doses have actually been applied. That covers both the Pfizer BioNTech COVID-19 vaccine, and the Moderna version. The CDC tracks distribution through the Vaccine Tracking System (VTrckS), and has been counting those numbers since December 13.

Despite the milestone in vaccinations, however, there are clear signs that people in the US aren't sticking to the guidelines for social distancing and minimizing travel. With Christmas fast approaching, the TSA said that almost 1.2 million travelers passed through its checkpoints in the US on Wednesday, December 23. That's less than 750,000 fewer travelers recorded than one year ago. Traveler throughput in general has been higher over the past week, averaging around 1 million people and suggesting broader travel plans than in the week prior to Thanksgiving.

It's that uptick which has some health experts concerned. "Vaccination is a critical tool in bringing this unprecedented pandemic to an end," the CDC said in a statement. "But until every person in the U.S. is able to get a COVID-19 vaccine, we continue to ask Americans to embrace proven public health strategies including social distancing, good hand hygiene, and wearing a mask in public to reduce the risk of transmission and protect our communities."

Adding to the challenge is the limited availability of vaccine in the US at present. Both Pfizer and Moderna have said that their supplies will be fairly constrained to begin with, although numbers are expected to increase dramatically in 2021. Currently, healthcare services are prioritizing front-line healthcare workers along with older individuals in nursing homes and assisted living facilities.

It could be, some estimates have suggested, Summer 2021 before more widespread vaccination is offered to the broader public. On Wednesday, Pfizer and BioNTech announced that the US government had ordered 100 million additional doses of its COVID-19 vaccine, doubling the total doses procured for use in the US since the drug gained Emergency Use Authorization (EUA) by the FDA. The 200 million doses are expected to be delivered by July 31, 2021.

It's worth noting, however, that it doesn't mean 200 million people can be vaccinated with them. The vaccines are designed to be given in a two dose regimen, meaning that the current US order from Pfizer is sufficient for 100 million vaccinations.