Kurzgesagt – In a Nutshell - The Side Effects of Vaccines - How High is the Risk?

Short Summary

Main recommendation: vaccination is worth its risks, because the side effects of vaccines such as MMR are far less dangerous than the diseases they prevent, such as measles. The video argues that vaccines trick the immune system into creating memory cells without the dangers of a real infection, and that herd immunity, with about 95% of people around a child vaccinated, is what protects children who cannot be vaccinated.

Key Points

• Vaccines work by mimicking an infection: killed or fragmented germs, or weakened live germs, prompt the immune system to build memory cells that stay for years and speed up future responses.
• In the video's hypothetical scenario of 10 million unvaccinated children, measles would cause about 2.5 million somewhat serious effects and roughly 20,000 deaths.
• The same 10 million vaccinated children would see about 120 somewhat serious side effects, including up to 10 boys with genital inflammation and up to 10 children with encephalitis, the most serious side effect, with almost all cases treatable in developed healthcare systems.
• The autism link to vaccines comes from a single source that has been repeatedly disproven, according to the video.
• The video found only a tiny handful of documented deaths from MMR vaccine side effects out of hundreds of millions vaccinated since 1971, while 110,000 people died of measles worldwide in 2017.
• Children who cannot be vaccinated depend on herd immunity, which requires that about 95% of the people around them be vaccinated.

Details Worth Noting

• Concrete instructions: The video gives no personal step-by-step medical instructions. Its actionable advice is to vaccinate children, and if a child cannot be vaccinated because of allergy or another reason, to become a strong promoter of vaccination among the people around them so herd immunity protects that child, with about 95% of people around the child needing to be vaccinated against measles.
• The video compares vaccine risk to seatbelts: rare freak accidents exist, but most people still wear them.
• Measles figures cited: about 135 million cases per year in the 1950s before the 1963 vaccine, and 83,000 cases in Europe in 2018 despite hundreds of millions being vaccinated in the West.
• Measles complications listed in the scenario include high fever and rash in 98%, diarrhea in 8%, ear infection in 7% (which can cause permanent hearing loss), pneumonia in 6%, encephalitis in 0.1%, and SSPE in 0.025%.
• MMR side effects in the scenario include fever in about 10%, mild rash in 5%, serious allergic reaction in up to 100 children (0.001%), and encephalitis in up to 10 children (0.0001%).
• The video notes that the flu virus mutates so often that it needs a new vaccine every year, while most vaccines protect for years or a lifetime.

Bottom Line

The video's core case is a risk comparison: the rare, mostly treatable side effects of MMR are dwarfed by the serious harm of measles, so declining vaccination shifts risk onto children and communities.