In the last century, vaccines have been one of the most vital contributions to global health and prevented many infectious, widespread diseases. Unfortunately, more than one in ten children don’t receive basic, yet vitally important, vaccines, and over three million children die each year due to preventable infections.

This lack occurs primarily in countries suffering from poor economic conditions and limited healthcare options, but can also be affected by cultural resistance to vaccinations. In fact, just ten countries account for approximately 60 percent of under vaccinated children.

Since its founding in 1974, the World Health Organization’s (WHO) Expanded Programme of Immunization has played a leading role in the creation, licensing and distribution of vaccines to many communities across the globe. Among these are six important vaccines that work to change the world.

Smallpox

The modern medical field of vaccination was initiated in 1796 when Edward Jenner created the smallpox vaccine by placing a small portion of the active virus cowpox, a disease similar to smallpox causing only minor infection in humans, into the body of a patient in order to build up the immune system.

In 1967, WHO launched a program to eradicate the disease, which still claimed 2.9 million lives per year in the first half of the 20th century. By 1980, though, WHO announced the complete eradication of smallpox.

Polio

Developed in the 1950s, the first polio vaccine brought an important change in vaccine science — by using an inactive form of poliovirus (IPV), which carried a lower risk of vaccine-induced infection. An oral polio vaccine (OPV), a weakened poliovirus, was later developed.

Today, three doses of IPV is 99-100 percent effective, virtually eliminating the spread of the disease in places where it is available. Polio has been successfully eradicated throughout much of the world due to these important vaccines.

Measles

The measles vaccine, one of the most important vaccines of the 21st century, was first readily available in the U.S. in the 1970s. It became mandatory for school-aged children, which resulted in few measles cases overall. Increased worldwide availability between 2000 and 2015 brought a nearly 80 percent decrease in measles cases resulting in death.

However, 18 countries in Europe, as well as many African countries, have continued to suffer from this disease with over 14,000 cases occurring between 2016 and 2017. The vaccine was recently made mandatory in France, Italy and Germany — children without proof of up-to-date vaccinations, including measles, cannot be admitted to nurseries and schools.

Influenza

The influenza vaccine, which differs from other vaccines as it is made to target the predicted strain of the virus each year, has become a yearly staple in many Americans’ lives. In fact, this important vaccine changed the outcome of potential influenza epidemics due to its low herd immunity threshold — the percent of people in a population needing vaccinations in order to maintain the health of the entire population — of just 33 to 44 percent.

While the influenza vaccine is cheap and widely distributed across the U.S., developing countries often have limited access to the vaccinations. WHO’s Global Action Plan for Influenza Vaccines is focused on reducing the influenza virus worldwide by increasing seasonal vaccine usage and furthering research and development.

In recent years, two important vaccines have been developed for tropical diseases in Africa and parts of southern Asia. While work has continued on both vaccines for decades, usable and distributable products have only been available within the past two years.

Malaria

The Institute of Health Metrics and Evaluation estimates that there were nearly 720,000 deaths caused by malaria in 2016 alone, the majority occurring in African countries; seventy-two percent of these deaths were children under the age of five. While the infectious agent — infected mosquitoes — has been known and studied since the late 19th century, a safe and effective malaria vaccine has only recently been tested and will be implemented in 2018.

The malaria vaccine, RTS,S, will be available in Kenya, Ghana and Malawi through the partnership of WHO, the Ministry of Health of Kenya and a collaboration between PATH, a nonprofit organization focused on global health innovation, and GSK, a research-based pharmaceutical company.

The vaccine will help protect children from malaria at least three years after the initial vaccination, working in tandem with other established prevention tools such as bednets and insecticides. These efforts will work to reduce the spread of this deadly disease.

Ebola

First discovered in 1976, the ebola virus has a fatality rate averaging nearly 50 percent. The severe 2014-2016 outbreak in west Africa accelerated the search for an effective vaccine. The rVSV-ZEBOV vaccine uses an inactivated form of this dangerous virus and protects against one of five species of the ebola virus — zaire, which accounted for all ebola outbreaks since 2012.

Trial and distribution of this vaccine was led by WHO, Guinea’s Ministry of Health, the Norwegian Institute of Public Health and Medecins sans Frontieres. Trials starting in 2015 were performed as a ‘ring vaccination,’ in which only those with increased probability of contact with the disease are vaccinated, thus assisting in herd immunity even if not all members of the population are immunized.

Vaccines have furthered the goal of creating a healthier world for all. Increasing their effective distribution in developing countries, which continue to have limited access to the healthcare and preventative medicines, has the potential to reduce the suffering of those in poverty and rural areas.

Through these six vaccines, one can see the possibility of a future without devastation by disease for children and adults alike, regardless of one’s economic status or geographical location. Now, time will tell which vaccine will be developed next.

– Anna Lally
Photo: Flickr