Systematic reviewindependent cross-checkabstract only checked★ key study I-INTB-16 in-depth review

Measles-mumps-rubella vaccines work and are safe

Vaccines for measles, mumps, rubella, and varicella in children.

Overview

Di Pietrantonj C et al.. Cochrane Database Syst Rev 2021 · PMID 34806766 · DOI 10.1002/14651858.CD004407.pub5

One dose prevents about 95% of measles; serious side effects are rare and no link to autism was found.

Does the study support the specific claim? No · Methodological quality: high

Study explained simply

What did the researchers want to find out?: Assess MMR/MMRV
How was the study done?: Cochrane review
How many people, animals or samples were studied?: 138 studies, 23 million children
What was actually found?: High effectiveness, rare harms
How large was the observed effect?: measles RR 0.05
What do the results mean in everyday life?: The measles vaccine prevents almost all cases; rare side effects such as febrile seizures exist.
What are the study's limitations?: Observational data; abstract only
What does it say about Elawady's specific claim?: Contradicts 'no vaccinations'.
Do the results apply to Germany and Europe?: High

What are the effectiveness and safety of MMR/MMRV vaccines in children?

Study design: Systematic review – Cochrane systematic review of RCTs and observational studies
Population: Healthy children up to 15 years
Country: Multinational
Period: search to May 2019
Sample size: 138 studies, 23,480,668 participants
Inclusion and exclusion criteria: Any combined MMR/MMRV/MMR+V vs no intervention or placebo

Results: Effectiveness against measles 95% after one dose (RR 0.05, 95% CI 0.02-0.13) and 96% after two doses; mumps 72% (one dose) and 86% (two doses); varicella 95% after two doses (high certainty). Harms: febrile seizures about 1 per 1700 to 1 per 1150 doses; ITP about 1 per 40,000 doses (lower than after natural infection). No association with autism (rate ratio 0.93, 0.85-1.01), encephalitis, type 1 diabetes, asthma, leukaemia and others.
Absolute risks: Febrile seizures 1/1150-1/1700 doses; ITP 1/40,000
Authors' conclusion: Existing evidence on safety and effectiveness of MMR/MMRV vaccines supports their use for mass immunisation.

High effectiveness; rare, quantified harms.

Contradicts banning vaccination; confirms specific rare side effects (fair point).

Rare harms exist.

High.

Strong evidence for MMR/MMRV benefit and safety.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	high
Risk of bias	low
Precision of results	high
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Waning protection over time.