Modern medicine has shaped the way the world looks today. It ‘s hard to imagine how the current society would look like if life expectancy were still stuck at 30-35 years. Thanks to the rapid advent of healthcare technology we no longer have to fear to die from minor illnesses or even epidemics.

The 20th century will always remain in history as the time when scientists managed to win the battle against treacherous ailments. Here are some of the now-defunct diseases that used to kill entire populations in the past:

Chicken Pox

Varicella-zoster is a virus that affects humans mostly in their youth through red blisters that cover the entire body. Also known as chicken pox, this ailment is now entirely curable through a vaccine that was perfected in 1995. It is unclear where the virus made its first appearance, but Europeans had grown immune to its fatal consequences by the 15th century. Unfortunately, at that time they could still transport chicken pox in a dormant state and transfer it to other individuals. In the end, it became one of the leading causes of the death of millions of people from newly colonized lands, where immunity against the disease was null.

Smallpox

Similar to chicken pox, smallpox is a childhood disease that spreads through small, red bumps on the entire body. Contracting a form of smallpox makes you immune to the illness for the rest of your life. The first vaccine against this ailment was developed in 1796, but it took scientists over 200 years to deem the virus dead. Nowadays, with only small exceptions, smallpox is considered eradicated and improbable of causing a major epidemic.

Measles

Measles used to be a major health concern until 60 years ago. The disease affected mostly children and it usually started with symptoms like rashes, pink eye, and red lumps. Unfortunately, this condition severely weakened the immune system, and pneumonia often followed, sometimes with fatal consequences. Thankfully, in 1963 medical researchers developed a cure in the form of a vaccine that offers lifetime immunity. Nowadays, people may contract measles in minor ways, but the symptoms are bearable, and the chances of dying from it are close to zero.

Polio

Before the middle of the 20th-century poliomyelitis was a common disease that affected a large segment of the population. Because it occurred mainly in children, doctors used to call it infantile paralysis. Its symptoms varied from muscle pain to flu-like conditions, and it left the patients with permanent problems of motricity. In 1955, Dr. Jonas Salk came up with an adequate remedy for polio by developing a vaccine from a dead strain of the virus. Dr. Salk made the vaccine available for free on a worldwide scale, and the disease was eradicated in just a few decades.

Rabies

Rabies is still a significant health concern across the world. However, a handful of countries has managed to eliminate the threat of canine rabies entirely. The US is one of the nations that developed a vaccine which prevents dogs from contracting rabies, a disease that can be fatal for both canines and humans. The anti-rabies cure was released in 2007, and it ensures complete healing if it is administered in maximum two weeks after exposure.