A new review of research, using data on over 23 million children across the world, has confirmed that the MMR vaccine is effective, safe, and not associated with an increased risk of autism.

Of course, this is not the first time the safety of the MMR/MMRV vaccine has been established. It’s been proven time and time again. However, misinformation and popular conspiracy theories about the safety of vaccines continue to rumble on, which has contributed towards a global resurgence of preventable diseases, like measles. The current global outbreak of Covid-19 may well act as a reminder to the world of the importance of successful vaccinations. 

The MMR (measles, mumps, rubella) jab is a combined vaccine that protects against all three viral infections, while the MMRV vaccine also includes a vaccine against varicella – better known as chickenpox. In a new review published by British policy institute Cochrane, researchers looked at 138 randomized and non-randomized studies, 51 of which assessed how effective the vaccines were at preventing the diseases and 87 that assessed their potential side effects. All total, the studies contained data on 23,480,668 children and their responses to the MMR or MMRV vaccine.

First up, the review found that diagnosed cases of autism were similar in vaccinated and unvaccinated children. They also found no evidence for any link between participants that received the MMR/MMRV vaccines and encephalitis, inflammatory bowel disease, Crohn's disease, cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.

”In this review, we wanted to look at evidence for specific harms that have been linked with these vaccines in public debate – often without rigorous scientific evidence as a basis,” lead author Dr Carlo Di Pietrantonj, a biostatistician from Italy’s Regional Epidemiology Unit SeREMI, said in a statement.

The vaccines were also shown to be effective at preventing diseases. One dose of vaccine was 95 percent effective in preventing measles. After two doses, effectiveness rose to around 96 percent. For mumps, the effectiveness was 72 percent after one dose and 86 percent at two doses. One dose was 89 percent effective in preventing rubella and one study found the MMRV vaccine was 95 percent effective at preventing chickenpox.

So, if these are the statistics, then where does the doubt came from? 

Much of the skepticism about the MMR vaccine can be traced back to Andrew Wakefield and his 1998 study, described by scientists as “the most damaging medical hoax of the last 100 years." The study of just 12 autistic children found a link between some of the children's autism symptoms and the MMR vaccine, even suggesting the symptoms appeared within days of the vaccination. 

It later transpired that Wakefield had falsified data and the research was subsequently retracted from the journal. It was also alleged in 2004 that Wakefield had undisclosed financial interests in finding this supposed link, with the aim to discredit the three-in-one vaccine. Wakefield has since had his medical license revoked and can no longer legally practice as a doctor in the UK.

A more recent study in 2017 linked aluminum in vaccines to autism. The study was swiftly withdrawn by the journal after scientists noticed the images had been manipulated, and one of the co-authors claimed that figures in the paper were deliberately altered before publication.