Tag: morbidity

We Know Vaccines Work

We know vaccines work.

How well do they work?

In addition to eradicating smallpox, did you know that vaccines have helped eliminate four other now vaccine-preventable diseases?

  1. diphtheria
  2. neonatal tetanus
  3. polio
  4. congenital rubella syndrome

And unlike measles, which was declared eliminated in 2000, we really don’t see these diseases anymore.

We Know Vaccines Work

How well do vaccines work?

Let’s look at the disease counts (morbidity data), how many kids got sick, just before we developed a vaccine and where we are now:

DiseasePre-Vax EraNow% Decrease
Smallpox110,672last case 1977 100%
Diphtheria30,508199.9%
Pertussis265,26913,43994.9%
Tetanus6012096.7%
Neonatal Tetanus1,000+0100%
Polio21,269last case 1993100%
Measles763,094372 99.9%
Mumps212,9342,25198.9%
Rubella488,796599.9%
Congenital Rubella Syndrome20,0000100%
Hib invasive18,0002799.9%
HepB300,0002,79999.1%
Perinatal HepB16,20095294.1%
Pneumococcal invasive64,40098698.5%
HepA254,51811,16695.6%
Varicella5,358,5956,89299.9%

Sandra Roush and Trudy Murphy provided us with pre-vaccine baselines for 13 vaccine-preventable diseases in their article, Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States.

“A greater than 92% decline in cases and a 99% or greater decline in deaths due to diseases prevented by vaccines recommended before 1980 were shown for diphtheria, mumps, pertussis, and tetanus. Endemic transmission of poliovirus and measles and rubella viruses has been eliminated in the United States; smallpox has been eradicated worldwide. Declines were 80% or greater for cases and deaths of most vaccine-preventable diseases targeted since 1980 including hepatitis A, acute hepatitis B, Hib, and varicella. Declines in cases and deaths of invasive S pneumoniae were 34% and 25%, respectively.”

Roush et al on Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States.

Their study, which came out in 2007, used morbidity (2006) and mortality (2004) data that was recent at the time. The data has held up very well since then, looking at 2018 statistics in the National Notifiable Infectious Diseases Weekly Tables (see below), even with talk of waning immunity for some vaccines.

But can’t you explain all of this decline away by talking about better hygiene, sanitation, and nutrition?

Of course not!

“…for those trained in pediatrics in the 1970s, Hib (Haemophilus influenzae type b) was a horror.”

Walter Orenstein, MD

The pre-vaccine era for Hib was just before 1988, when the first Hib vaccine came out. We had good hygiene, sanitation, and nutrition in the 1980s and yet, a lot of kids died from Hib meningitis and epiglottitis. At least they did until he got a vaccine to prevent it.

And if it was better hygiene and sanitation, etc., why did it affect every disease at a different time? And why hasn’t better hygiene and sanitation stopped RSV, HIV, norovirus, Zika, and all of the other non-vaccine-preventable diseases?

Although there was a decline in mortality rates at the beginning of the 20th Century for all diseases thanks to better hygiene, sanitation, and nutrition, that effect plateaued by the mid-1930s. And since a lot of people were still getting sick, remember everyone used to get measles, even if a small percentage would die, it would add up to a lot of deaths!

Vaccines aren’t perfect, but they are safe, with few risks, and work well. Get vaccinated and protected if you want to keep from getting and bringing back these now vaccine-preventable diseases.

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