Author: Natalia Khalatyan
Editors: Shamsia Ahmed and Shannon Tan
Artist: Tiffany Gao
As the Covid-19 virus runs rampant around the globe during the biggest pandemic of our time, scientists are working tirelessly to test and develop vaccines against it. The vaccine will prevent further spread of the virus by creating lasting immunity or resistance in vaccinated individuals. Vaccines also aid in disease eradication efforts, first being in the mid-20th century in the fight against smallpox, a highly contagious disease characterized by its distinct violent skin rash that left the majority of infected scarred or even blind (“Smallpox”). There’s no effective treatment against smallpox and about a third of sick patients died from infection with an estimate of up to 500 million deaths in the 20th century alone. Yet by 1980 the World Health Assembly declared smallpox the first disease to be eradicated, or eliminated from the human population, through intensive vaccination efforts and surveillance.
There are a few reasons that made smallpox a great candidate for eradication, unlike any disease before it. First, the vaccine was readily available unlike with the case of other diseases such as AIDS. Smallpox is also highly visible with rapid symptom onset, allowing for quick detection and tracing of at-risk individuals who may have been exposed to the virus. Humans are also the only ones who can catch and transmit smallpox, so it is unable to jump species and remain hidden in the animal population. In addition, previously infected individuals also develop lifelong immunity, similar to that ideal effect of a vaccine, and therefore cannot get re-infected with smallpox again (“History of Anti-Vaccination Movements”).
This method of tracing and vaccinating at-risk individuals who have been in contact with an infected person is known as “ring vaccination” and is a global effort that is only as effective as the disease and people allow it to be. For example, recent efforts with polio eradication have posed some challenges. Unlike smallpox with its rash, this disabling and life-threatening illness has indistinguishable early symptoms, oftentimes spreading undetected (“History of Anti-Vaccination Movements”). Malaria eradication efforts also failed due to a lack of highly skilled medical professionals who can properly diagnose patients from blood smears. Malaria vaccines also do not provide lifelong immunity thus further complicating the efforts (“History of Anti-Vaccination Movements”). In the case of Covid-19, contact tracing becomes an issue. Since the virus infects bats, elimination from the human population is not sufficient since the disease can re-emerge into the human population.
In theory, any disease caused by a virus can be eradicated yet the growing mistrust in science and the anti-vaccination movement poses a problem. The success of disease eradication, as with any public health program, greatly depends on the public's cooperation, commitment, and feasibility. Civil disturbances and poor infrastructures will disrupt any eradication efforts. They should also not disrupt the integrity of the healthcare system set in place and have consensus within the scientific community about the plan of action. Possible consequences of failure, financial costs, and divergence of attention from other health issues must also be carefully considered.
Currently, there are efforts to eradicate the first parasitic disease, dracunculiasis, or Guinea-worm disease contracted from the consumption of unfiltered and contaminated drinking water. Parasites are tiny organisms that are generally much larger than viruses and if waterborne can be eliminated through water filtration systems, making parasitic diseases great candidates for eradication campaigns. The control strategy is also relatively simple and cost-effective and countries who do not report any cases within a year are certified dracunculiasis free (“The Global Eradication Campaign”). Although not every disease makes for a great eradication candidate it gives hope that devastating diseases that used to pose a serious threat to the public can now be permanently removed from the human population.
Corona, Angel. “Disease Eradication: What Does It Take to Wipe out a Disease?” ASM.org, 6
Dowdle, Walter. “The Principles of Disease Elimination and Eradication.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 31 Dec. 1999, www.cdc.gov/mmwr/preview/mmwrhtml/su48a7.htm.
“The Global Eradication Campaign.” World Health Organization, World Health Organization,
9 May 2018, www.who.int/dracunculiasis/eradication/en/.
“History of Anti-Vaccination Movements.” History of Vaccines, 2018, www.historyofvaccines.org/index.php/content/articles/history-anti-vaccination
“Smallpox.” Centers for Disease Control and Prevention, Centers for Disease Control and
Prevention, 12 July 2017, www.cdc.gov/smallpox/index.html.