Pfizer and Moderna focus on COVID-19 variant booster shots

Moderna and Pfizer are both testing COVID-19 booster shots intended to address coronavirus variants of concern, the companies announced in separate press releases this week. Such third shots aren’t yet available and, at this point in time, aren’t needed; however, the presence of certain SARS-CoV-2 variants have the companies preparing as the pandemic evolves. For its part, Pfizer announced on …