herd immunity

Herd immunity seems to be a relatively simple idea. The fewer susceptible individuals in the herd, the more difficult it is for the disease to be transmitted.
Infections spread from one susceptible individual to another, a chain of exposures or contacts – it is the basis for track and trace.
While Americans were (sort of) celebrating the Fourth of July, the coronavirus kept raging on. Some relevant developments and analysis have occurred in the past few days that might shed a little more light on how the pandemic will unfold.
For social and economic reasons, the lockdown simply cannot last much longer. As the country begins to reopen, there will be several major unanswered questions, perhaps the biggest of which is, "Will there be a second wave of COVID-19?"
The HPV vaccine has been the subject of some controversy in the United States.
Childhood vaccines via Shutterstock
Measles is a highly contagious viral infection that once burdened an average 53,000 people in the United States.