The highly transmissible omicron variant of the coronavirus has taken over as the dominant strain in the United States, resulting in breakthrough infections among the vaccinated. Omicron has sparked alarm both internationally and in the United States, where it accounted…

After making a vaccine for coronavirus, you have to get it to the masses. But that’s not so easy for a so-called cold chain vaccine, requiring exacting temperatures across its journey. It also takes two shots. Vaccinating much of the…