If you’re like me, you’re starting to know people who have been vaccinated against COVID-19 – or at least had their first dose. This, of course, is wonderful news for them, but it does beg a couple key questions. How protected are they? And from the perspective of vaccine availability, should state health agencies get one dose into as many arms as possible, rather than prioritizing finishing two-dose regimes?

Dr. William Petri from the University of Virginia breaks it down for us, citing recent studies from Israel, the U.K., and a reanalysis of clinical trial data of the Pfizer vaccine. In short, Petri explains how a single dose provides some immune protection after about a week, but the second shot, for either the Pfizer or Moderna vaccine, is recommended to make it more effective.

As more Americans get vaccinated in the weeks and months ahead, will they need “vaccine passports” to travel to other countries or even enter a workplace? Tufts cybersecurity scholar Laurin Weissinger argues there are a number of security and privacy concerns with app-based vaccine passports, particularly if app developers seek to monetize this information by, for instance, combining it with personal health data. His advice? Use paper records, verified by a QR code.

We’ve all heard about the problem of methane produced by ruminants, such as cows. Two researchers from the University of California Davis just published a study showing that adding only one to three ounces of red seaweed to cow feed per day can reduce both methane emissions and feed costs without affecting meat quality. As for the taste, a panel of consumers could not tell the difference between beef from cattle that consumed seaweed and those that did not. And the cows themselves adapted quickly to the seaweed supplements.

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