Recently, a new COVID-19 variant was discovered in the United Kingdom that spreads more quickly and efficiently than other virus strains. A team of German scientists studied the effectiveness of the Pfizer vaccine against this new strain in a group of 40 participants, following the recommended dosing regimen (two doses administered 21 days apart). They found that the vaccine is only slightly less effective against this strain compared to others, meaning that the Pfizer vaccine will still protect the general population. There was also no difference in efficacy found between younger and older participants. The constant evolution of COVID-19 reveals the importance of continuous monitoring of viral changes that could potentially reduce the efficacy of authorized vaccines. However, the new mRNA-based vaccines developed by companies such as Pfizer facilitate their adaptation to new virus strains.