From Discoveries To Lifesavers - Milestones In Vaccination

By Sabine Donders and Candela Iglesias Chiesa

If you had been born in 1915 (in a high-income country), your life expectancy would have been 48 to 54 years. You would have had a significantly higher chance of dying before the age of 5 compared to today.

The huge increase in life expectancy in the past 100 years is linked to several causes, and without a doubt, the incredible achievements in vaccination are one of them. The WHO and the CDC estimate that around 4–5 million deaths worldwide are prevented by vaccination each year.

Let’s dive into the amazing (and sometimes little talked about) successes in global health linked to the discovery (tricky) and global deployment (super tricky) of vaccines.

Where it all started: the development of the smallpox vaccine

Let´s start with one of the most unbelievable achievements of humankind: the eradication of an infectious disease from the world. One that was once considered one of the world’s deadliest diseases, no less. We are talking about smallpox, of course.

The journey of vaccine development started in the 16th century. The initial technique, variolation, was based on the observation that if you got smallpox once, you couldn’t get it again. Thus, scientists isolated small amounts of the smallpox virus from infected patients and introduced it to uninfected people with the hope of providing immunity against a potentially severe natural infection. This technique was later replaced with a more precise and effective technique: vaccination.

The technique of vaccination was based on the discovery that infection with a milder pox variant, cowpox, also led to immunity to smallpox.

Vaccination played a crucial role in the global eradication of the smallpox virus. The last reported case of smallpox occurred in Somalia in 1977. In 1980, the WHO declared smallpox eradicated.

Polio Vaccination

Another disease in which the development of vaccines has worked miracles is polio! This disease was once one of the most feared childhood diseases worldwide. Desperate parents would send their children away to rural areas when there were outbreaks in the city.

Today, though, less and less people worldwide have ever seen someone afflicted with it and even fewer people need to worry about contracting it.

The breakthrough in the prevention of polio came in the 1950s with the development of the inactivated and oral (live-attenuated) polio vaccines (IPV and OPV) by scientists Dr. Jonas Salk and Dr. Albert Sabin, respectively. These vaccines were crucial in preventing the spread of the virus.

Large international organizations, such as the WHO, supported worldwide vaccination campaigns. The WHO launched the Global Polio Eradication Initiative (GPEI) in 1988.

The results speak volumes: in 1994, the Americas became the first region to be declared polio-free, showcasing the effectiveness of widespread vaccination campaigns. And the progress keeps rolling! As of October 2023, we’re down to just two endemic countries.

We are now closer than ever to the global eradication of polio, all because of the power of vaccination and the ability of people to come together to set up ambitious initiatives to ensure every last person needing a vaccine gets it.

Recent developments in the world of vaccination

The development of vaccines hasn’t stopped. In the last two decades, many more vaccines have been developed, tested, and implemented.

Think for example, of the HPV vaccine, which protects many women around the world from the devastating effects of cervical cancer. Australia, one of the early implementers of the HPV vaccine, is even talking about eradicating cervical cancer in the coming decades.
Then there is malaria, a deadly killer in tropical zones that has been one of the main drivers of child mortality for the past century. The first vaccines have been approved very recently (2021 and 2023).
And of course, we are all familiar with the COVID-19 vaccines, which were developed and deployed at breakneck speed and have helped to reduce the rate of transmission of the latest pandemic.

In short, vaccines have been saving countless lives around the world and can therefore be considered one of the most successful innovations in the field of global and public health.