Five things to know about bird flu

There have been major outbreaks around the world in the recent past, including four from 2014 to 2017, according to the Centers for Disease Control and Prevention.

So what makes this time different, and at what point should you be concerned?

Here are five things you should know about bird flu.

...

Researchers estimate vaccines have saved 154 million lives over past half-century

An international team of health and medical researchers including workers at the WHO, working with economists and modeling specialists, has found that the use of vaccines to prevent or treat disease has saved the lives of approximately 154 million people over the past half-century.

In their study, published in The Lancet, the group used mathematical and statistical modeling to develop estimates for lives saved due to vaccines and then added them together to find the total.

...