Usability, inclusivity, and content evaluation of COVID-19 contact tracing apps in the United States.

We evaluated the usability of mobile COVID-19 contact tracing apps, especially for individuals with barriers to communication and limited digital literacy skills. We searched the Apple App Store, Google Play, peer-reviewed literature, and lay press to find contact tracing apps in the United States. We evaluated apps with a framework focused on user characteristics and user interface. Of the final 26 apps, 77% were on both iPhone and Android. 69% exceeded 9th grade readability, and 65% were available only in English. Only 12% had inclusive illustrations (different genders, skin tones, physical abilities). 92% alerted users of an exposure, 42% linked to a testing site, and 62% linked to a public health website within 3 clicks. Most apps alert users of COVID-19 exposure but require high English reading levels and are not fully inclusive of the U.S. population, which may limit their reach as public health tools.

Injectable, Tough Alginate Cryogels as Cancer Vaccines.

A covalently crosslinked methacrylated (MA)-alginate cryogel vaccine has been previously shown to generate a potent response against murine melanoma, but is not mechanically robust and requires a large 16G needle for delivery. Here, covalent and ionic crosslinking of cryogels are combined with the hypothesis that this will result in a tough MA-alginate cryogel with improved injectability. All tough cryogels can be injected through a smaller, 18G needle without sustaining any damage, while covalently crosslinked-only cryogels break after injection. Cytosine-phosphodiester-guanine (CpG)-delivering tough cryogels effectively activate dendritic cells (DCs). Granulocyte macrophage colony-stimulating factor releasing tough cryogels recruit four times more DCs than blank gels by day 7 in vivo. The tough cryogel vaccine induces strong antigen-specific cytotoxic T-lymphocyte and humoral responses. These vaccines prevent tumor formation in 80% of mice inoculated with HER2/neu-overexpressing DD breast cancer cells. The MA-alginate tough cryogels provide a promising minimally invasive delivery platform for cancer vaccinations.