We know that vaccines work, but it’s good to have data such as chickenpox has been almost eliminated in the USA because of the chickenpox vaccine. We should be dancing in the streets because of this.
Let’s take a look at this new data, but first, we need to talk about chickenpox and the vaccine. Just to make sure everyone is up-to-speed with accurate information.
Chickenpox and the Varicella vaccine
Despite the claims of the anti-vaccine crowd, chickenpox is a severe disease with some dangerous complications.
Chickenpox is an infection caused by the Varicella zoster virus (VZV). Although most cases are in children under age 15, it can attack older children and adults can get it. The virus spreads easily from person to person. (To be clear, chickenpox is not even distantly related to monkeypox.)
The classic symptom of chickenpox is an uncomfortable, itchy rash. The rash turns into fluid-filled blisters and eventually into scabs. It usually shows up on the face, chest, and back and then spreads to the rest of the body.
Other symptoms include:
- Fever
- Headache
- Tiredness
- Loss of appetite
The disease usually lasts from 5-10 days.
Unfortunately, VZV stays in the body, usually in nerve roots along the spine, and, for unknown reasons, returns as a debilitating disease called shingles, which can be prevented with another vaccine.
Before the launch of the vaccine, according to the CDC, “an average of 4 million people got chickenpox, 10,500 to 13,000 were hospitalized, and 100 to 150 died each year.” And untold numbers which eventually developed shingles decades later.
The VARIVAX chickenpox vaccine was first licensed in Japan and the USA in 1995. In the USA, the CDC recommends the first dose at age 12 through 15 months and the second dose at age 4 through 6 years.
Decline of chickenpox
In a presentation during IDWeek (ID stands for infectious diseases), Mona Marin, MD, of the CDC’s National Center for Immunization and Respiratory Diseases, reported the results of their analysis of chickenpox cases, hospitalizations, and deaths before and after the launch of the chickenpox vaccine in 1995.
Here are some key results:
- Within 10 years of initiating vaccination with one dose of the varicella vaccine in 1995, the incidence of chickenpox cases, hospitalizations and deaths declined by 71% to 91% compared to the years before the vaccine was available.
- In 2007, the CDC recommended a two-dose schedule for the vaccine because there was still limited transmission of the disease. By 2019, cases decreased by over 97%, hospitalizations decreased by 94%, and deaths decreased by 97% compared to the years before the vaccine became available in 1995. I know that this is supposed to be a fact-filled recitation of data, but those are impressive decreases.
- Among individuals under the age of 20, the results were even more impressive — cases decreased by 99%, hospitalizations by 97%, and deaths by 99%.
- Individuals over 50 years of age saw a 97% reduction in deaths from chickenpox.
- During the period studied before the introduction of the vaccine (1990-1994), the annual mortality rate from chickenpox was 0.4-0.6 per million population per year.
Summary
Over the last 25 years, vaccination resulted in 91 million cases prevented, 238,000 hospitalizations prevented, and 1,933-2,446 deaths prevented. And there is probably also an impressive number of shingles cases that were prevented because these millions of kids and young adults avoided contracting the virus which eventually leads to shingles.
This is a success story beyond anyone’s wildest imagination. And it’s all thanks to vaccines.
