What Do Smallpox, Diphtheria, and Influenza Have In Common?
What Do Smallpox, Diphtheria, and Influenza Have In Common?
Answer: they are all vaccine-preventable diseases
Each August we celebrate National Immunization Awareness Month. Throughout the month those of us in the medical and public health communities highlight the importance of vaccinations for all people of all ages.
Vaccines save lives.
In celebration of National Immunization Awareness Month — I have put together a series of posts for the month of August focused on the history of vaccines, how the immune system works, the anatomy of a clinical trial (to test new vaccines), herd immunity, and three of my favorite vaccine-preventable disease (see below).
This series aims to educate you about the immune system & immunity, how vaccines are developed, and the diseases that vaccines prevent. And with the knowledge gained, I want to empower you to become fully vaccinated AND an advocate for vaccines in your community.
Here is part #5 in the series (the final post) celebrating National Immunization Awareness Month — THREE OF MY FAVORITE VACCINE-PREVENTABLE DISEASES.
(Be sure to check out part #1, part #2, part #3, and part #4 in this series)
Vaccines are a form of primary prevention.
When we use the term PRIMARY PREVENTION in public health, we mean that a vaccine is given prior to a disease developing or before illness occurs. Labeling vaccines as a form of primary prevention does not mean vaccines prevent all disease. The term primary does not mean superior to or better than other forms of prevention. It is merely a term to denote timing. Primary prevention occurs before an individual has a disease and often occurs before exposure to a pathogen/infectious agent occurs (just a few vaccines, monkeypox and rabies among them, can be given after an individual is exposed to a pathogen).
Vaccines were never meant to be perfect or a silver bullet to end the spread of infectious diseases.
Instead, vaccines are developed to meet one of three objectives —
Eradication/elimination of a disease
Prevention of disease
Prevention of severe complications, hospitalizations, or death from a disease
Vaccines are not designed to be all things to all people. They are developed to do one of the three objectives above.
Only one disease has been eradicated (aka global elimination) through vaccination. And that disease is smallpox.
In all honesty, smallpox was the ideal disease to eradicate — it does not have an animal reservoir (it only spreads from person to person), it is easy to diagnose the disease (because of the pox), and the vaccine can be administered after a person has been exposed. Despite how theoretically easy smallpox was to eradicate, it took nearly $300 million and 10 years to eradicate smallpox.
Dr. Larry Brilliant noted that the monumental effort required to eradicate smallpox —
“In 1980 we declared the globe free of smallpox. It was the largest campaign in United Nations history until the Iraq war. A hundred and fifty thousand people from all over the world, doctors of every race, religion, culture and nation, who fought side by side, brothers and sisters, with each other, not against each other, in a common cause to make the world better.”
Eradication requires time, money, commitment, and a disease that can be eradicated. If eradication is not the goal, an alternative is to develop a vaccine that will prevent disease. The ability to do so requires both technologies to stimulate the immune system appropriately AND a virus that is stable.
If the virus is constantly mutating/changing (read: it is unstable), even with the most technological advances in vaccinology we may not be able to prevent disease through vaccination.
Many diseases can be prevented through vaccination — polio, measles, chickenpox, and diphtheria. Diphtheria is a disease that is often neglected in conversation and forgotten because the vaccine is packaged in a single shot known as the DTaP (diphtheria-tetanus-pertussis). We don’t talk about diphtheria often (and many people do not know what the D stands for in the vaccine) because the disease can be prevented through vaccination.
Diphtheria is a gnarly disease.
Diphtheria is a bacteria that causes a serious infection in the mucous membranes of the nose and throat. Advanced/untreated disease can cause damage to the heart, kidneys, and nervous system.
The defining clinical characteristic of a diphtheria infection is the formation of a thick, grey membrane in the back of the throat. The membrane is comprised of dead cells that have been killed by a poison released by the diphtheria bacteria. This membrane can become so large that it obstructs an individual’s breathing.
In many parts of the world, where vaccination rates are high, we do not see diphtheria infections, but the bacteria are still circulating and in places or at times when vaccination rates are low, diphtheria will resurface causing a lot of pain, suffering, and death.
Other diseases — such as influenza and COVID-19 — cannot yet be prevented with a single vaccine, but the vaccine can be used to stimulate the immune system in order to prevent severe illness or death. One of the key reasons why the vaccine is unable to prevent illness is because the viruses that cause the disease are changing all the time (read: they are unstable). There are hundreds of strains of the influenza virus; right now we do not have a vaccine that can account for the many differences that exist between influenza strains.
The SARS-CoV-2 virus has also evolved and changed considerably during the past (nearly) three years. While the differences between the Delta and the BA.5 subvariant may be subtle to the untrained eye, the differences are enough to trick or evade the immune system and antibodies created by vaccination.
While the virus may be able to surpass the early alert part of the immune system, vaccine-induced immunity does kick in once the pathogen has been identified. This usually happens after there is enough virus in the body to cause illness, but the immune system will respond and the vaccine will prevent severe illness, hospitalizations, and death.
From the very beginning, the goal of the COVID-19 vaccines was to decrease the stress on our healthcare system and to decrease the number of deaths occurring, which all of the vaccines have successfully done.
SO… as National Immunization Awareness Month comes to an end, it is important to recognize, remember, and share with others that vaccines are designed to do one of three things. They can eradicate a disease, prevent an individual from getting sick, or prevent severe disease or death. It is not possible for each of the vaccines available to us to do all three of these things.
And vaccines are called primary prevention because they are given before illness manifests in the body.
Primary is not synonymous with perfection.
Vaccines are miraculous if you think about it. With a quick jab, you can prime your body to fight an infection before you get sick. Vaccines save lives, decrease the burden on our healthcare system, decrease disease spread, and make our communities healthy. Again, they are not perfect nor are they a silver bullet to make all illnesses go away. But they do improve our lives, increase our lifespan, and protect the most vulnerable in our communities through herd immunity.
For this reason, Dr. Bill Foege has said —
“Vaccines are the tugboats of preventive health.”
Vaccines are safe. And they are effective.
We all need to be up to date on our vaccinations.
Have questions? want to know more?
