Lest we forget, vaccines are one of the greatest medical inventions of all time. Without them, we would see cemeteries filled with children who would have died before they were even five years old. In fact, the best evidence we have tells us that vaccines prevented 200 million cases of diseases in the USA alone in the five decades since 1963.
A recent study, published in AIMS Public Health, estimates that around 200 million cases of polio, mumps, rubella, measles, adenovirus, hepatitis A and rabies have been prevented in the U.S. from 1963 through 2015 as a result of widespread vaccination. The study, authored by Leonard Hayflick and S. Jay Olshansky, two leading experts on public health and infectious diseases, also discloses that about 450,000 deaths have been avoided in the U.S during this period, although other studies put that estimate of lives saved at a much higher number.
Dr. Hayflick discovered the human cell strain, WI-38, in 1962 which was critical to the safe manufacturing of vaccines, which became widespread in 1963. According to the article, the vaccines produced from the WI-38 cell line prevented almost 4.5 billion occurrences of the diseases, and stopped them from returning to infect us. Dr. Hayflick developed the foundation that allowed the world to have relative safe and very effective tools to prevent infectious diseases.
Prior to the development of WI-38, anti-virus vaccines were grown in monkey cells, which had some issues that made many question their safety, although most of the concern appeared to be overblown. However, once the WI-38 was available, it became easier to develop and produce vaccines for many viruses.
Drs. Hayflick and Olshansky wanted to see what effect that seminal event had on public health. And the numbers were incredible.
Vaccines prevented 200 million cases of disease – the study
“Given the acknowledged large, positive global health impact of vaccines in general, I was curious what contribution my discovery of WI-38 in 1962 had in saving lives and reducing morbidity, since a large number of viral vaccines in use today are made with my cell strain or its derivatives,” said Hayflick.
Hayflick and Olshansky conducted a study to discover the total number of deaths and diseases prevented by vaccines that were produced with WI-38 cells through 2015. To reach an estimate, they used data regarding the number of cases and deaths for each disease – polio, mumps, rubella, measles, adenovirus, hepatitis A and rabies – that occurred in the USA in 1960. This was a legitimate starting point for data, prior to the vaccine era that was to follow in 1963. It was also the last year when vaccines were not widely available for the prevention of those diseases.
To reach the total number of lives saved and diseases prevented, the researchers multiplied the number of years vaccines have been prevalent by the number of deaths due to the disease.
The results are amazing:
| Disease | Year Introduced |
Pre-vaccine annual cases (U.S., 1960) |
Pre-vaccine annual deaths (U.S., 1960) |
Cases averted or treated with 95% coverage |
Deaths averted with 95% coverage |
| Poliomyelitis | 1963 | 36,110 | 5,865 | 2,547,045 | 413,692 |
| Measles | 1969-70 | 530,217 | 440 | 34,137,129 | 28,329 |
| Mumps | 1967 | 162,344 | 39 | 10,792,317 | 2,593 |
| Rubella | 1969 | 47,745 | 17 | 3,073,981 | 1,095 |
| Varicella (chicken pox) |
1995-96 | 4,085,120 | 107 | 133,691,807 | 3,436 |
| Hepatitis A | 1996 | 117,333 | 137 | 3,674,988 | 4,291 |
| Rabies | 1974 | 18,000 | – | 10,000,000 | – |
| Adenovirus | 1964 | 11,138 | – | 375,619 | – |
| Total (U.S.) | 5,017,007 | 6,603 | 198,292,887 | 453,435 |
(Note – pre vaccine cases and deaths were adjusted for larger population size using 1960 as a baseline.)
Without vaccines, we’d see 1,000 annual deaths from measles every year. Without vaccines, we’d see nearly 10,000 annual deaths from polio. Without vaccines, we’d see 200 or more deaths this year from chickenpox, which some people brush off as a minor disease with itchy skin.
And remember, these are numbers just for the USA. Worldwide, the numbers could be 20X higher. The number of cases of diseases prevented over this time could be in the billions, while saving millions of lives. No wonder vaccines are considered one of the greatest advances of science and medicine.
The authors point out something important the diseases vaccines prevented:
It is possible that the anti-vaccination movement has arisen among younger generations, in part, because they cannot bear witness to the tragedy of disfigurement, morbidity, and death caused by viral and bacterial diseases. However, as the 2015 outbreak of measles in California reminds us, the diseases our ancestors feared so much have not gone away—they lay dormant in many parts of the world where they resurface on occasion as a constant reminder of their existence. They will return if we lower our guard and allow herd immunity to drop below threshold levels. So as a potent reminder of their devastating impact, we provide images of what poliomyelitis, measles, and smallpox (three examples among many) does to human bodies. The anti-vaccination movement is a wake-up call to reinforce defenses against the diseases that plagued humanity from the beginning.
When I was young, my parents thought it was incredibly important that I got vaccinated. Why? Simply because they remembered all the diseases that ravaged communities and young lives, and they knew that vaccines were the best protection against this times. Even I remember a handful of kids in high school who still bore the effects of polio, and I cannot imagine any parent who ever want their children to be harmed by such a disease.
In case you missed the headlines, let me remind you again. Vaccines prevented 200 million cases of disease in America over five decades. As Dr. Hayflick puts it, “there is no medication, lifestyle change, public health innovation, or medical procedure ever developed that has even come close to the life-saving, life-extending, and primary prevention benefits associated with vaccines.”
Vaccines save lives.
Citations:
- S. J. Olshansky, L. Hayflick. The Role of the WI-38 Cell Strain in Saving Lives and Reducing Morbidity. AIMS Public Health , 2017, 4(2): 127-138. doi: 10.3934/publichealth.2017.2.127
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