March 31, 2021 - Podcast

Episode 110—Traveling, and vaccinated college students

As threats from additional COVID-19 strains emerge, policymakers around the globe are grappling with how best to respond, including difficult decisions about travel restrictions. Despite the fast pace of vaccination in the US, CDC guidelines still recommend delaying air travel, and many countries are weighing the imposition of "vaccine passports" for air travel. Empirical evidence can assist in weighing the tradeoffs for possible travel restrictions, and a recent Indiana University study has added some relevant insights. In the study, the authors examined whether air travel from early COVID-19 hot spots in the U.S. spread the virus to other parts of the country, and the answer appears to be no. Study authors Jeff Prince and Daniel Simon say the recommendation to not fly may be based on the fact that case numbers increase after mass travel, but it is not clear if this relationship is due to air travel per se. The researchers studied whether counties receiving more passengers from COVID-19 hot spots during the first quarter of 2020 experienced higher COVID-19 infection and death rates than counties receiving fewer passengers from COVID-19 hot spots. They found passengers traveling from COVID-19 hot spots at the onset of the pandemic did not spread the virus across the country. The results, they say, suggest that requiring negative COVID-19 tests for airline passengers may not be necessary. Indeed, they may be harmful, if they cause people to drive more, resulting in an increase in driving fatalities. The researchers say the findings lead them to think that requiring all airline passengers to provide proof of a negative COVID-19 test, even in the presence of new strains, will do very little to slow the spread of the virus.

In other news, Indiana University Bloomington has been selected as a study site and is enrolling participants for a new clinical trial that will evaluate whether the Moderna COVID-19 vaccine prevents infection and spread of the virus among college students and their close contacts. The clinical trial, called Prevent COVID U, will include approximately 12,000 college students ages 18 to 26 at more than 20 universities nationwide and follow them over a five-month period. Researcher Molly Rosenberg is co-leading the study and says the research team's findings will help scientists answer key questions about life post-vaccination, which will inform science-based decisions about mask use and social distancing for fully vaccinated people. Rosenberg says researchers know that we have a growing arsenal of vaccines that are extremely effective at preventing COVID-19 disease and death. But they don't know whether any of these vaccines, including the Moderna vaccine, prevent asymptomatic transmission. Before students can 'return to normal' after vaccination, this question needs to be answered, she says. People identified by study participants as their close contacts will also play an integral role in the study, as they will also be tested for COVID-19 infection, and the degree of COVID-19 transmission from vaccinated people will be determined by the infection rate in these close contacts.