Rising Covid-19 Breakthrough Cases Hinder Efforts to Control Virus

Covid-19 infections among vaccinated people are complicating the fight to bring the coronavirus under control. And in the U.K., where the path of the disease has been more closely tracked than just about anywhere in the world, they are on the rise. Breakthroughs happen because vaccines, while still offering strong protection against severe illness and death, aren’t bulletproof. The virus can still in some cases infect the body and replicate, causing illness, before the immune response can tackle it. Immunity from vaccination also wanes over time, prompting many countries, including the U.K., to roll out booster-shot campaigns.