The measles, mumps and rubella (MMR) jab is a safe and effective vaccination that protects against highly infectious and potentially life-threatening diseases.
The jab is so effective that in 2017, the World Health Organisation (WHO) declared that measles had been eliminated in Britain after no indigenous cases had been recorded for three years.
But England is currently facing the largest outbreak since the 1990s, with MMR vaccine uptake in children at a 12-year low, according to NHS statistics.
Doctors fear that low vaccine uptake has been influenced by misinformation circulating on social media, particularly in groups and feeds dedicated to new parents.
Dr James Gill, a GP and honorary associate professor at Warwick Medical School, explains everything you need to know about the MMR jab, how to differentiate between fact and fiction and debunks claims being made about the vaccine’s safety and efficacy.
How does the MMR jab work?
The MMR jab is a combined vaccine that protects against measles, mumps and rubella – three diseases that can spread among unvaccinated people.
These conditions can lead to serious health issues including meningitis, hearing loss and problems during pregnancy, the NHS states.
The MMR jab is delivered in two doses to babies and young children, with the first dose delivered to one-year-olds and the second dose administered to children aged three years and four months.
Older children and adults can also get the vaccine if it was missed when they were younger.
The MMR injection is a live vaccine administered into the leg or upper arm. Your immune system responds by producing cells which recognise and remember each of the three viruses, meaning the body rapidly produces antibodies if it comes into contact with the diseases in the future.
The NHS states that 99 per cent of people will be protected against measles and rubella after two doses of the vaccine and around 88 per cent of people will be protected against mumps.
Is the vaccine safe?
“The vaccine is safe – I cannot be any clearer than that,” said Dr Gill.
Dangerous misinformation circulating on social media continues to bombard new parents, i has revealed.
Here, Dr Gill debunks the key claims that parents have voiced concern about. He states:
Contracting measles is far more dangerous than having the jab
Dr Gill said the jab has been a “victim of its own success” as measles was eradicated so people have forgotten how dangerous it can be.
For every 1,000 children who get measles worldwide, one or two will die from it, according to the US Centre for Disease Control and Prevention.
Moreover, measles is “one of the most contagious viruses to affect mankind” so reaching herd immunity is vital to curbing the current outbreak, Dr Gill said.
He added that the disease can “reactivate” in the form of subacute sclerosing panencephalitis (SSPE) up to 12 years after the initial infection.
This is a progressive neurological complication of the measles virus with a high mortality rate and no cure to date.
The MMR jab does not cause autism
Much of the misinformation in circulation echoes the panic caused by disgraced former physician Andrew Wakefield, whose fraudulent research linking the jab to autism led to a sharp decline in vaccination rates following its publication in 1998.
In 2010, the General Medical Council found Mr Wakefield had been dishonest about his research, had acted against his patients’ best interests, and had mistreated developmentally delayed children.
Medical journal The Lancet fully retracted the article and Mr Wakefield was struck off the medical register and barred from practising medicine in the UK.
Dr Gill said the link between MMR and autism is “a lie predicated on an individual who was looking to profit from those lies”.
An investigation by the journalist Brian Deer showed that Wakefield had misstated the medical history of several of the children, who had begun to show symptoms before their MMR vaccine, or a long time afterwards.
Moreover, Wakefield had a conflict of interest since he was being paid by lawyers preparing a case against the vaccine-makers.
He called for the government to return to single shots for measles, mumps and rubella but eight months earlier, he’d filed a patent application for his own measles vaccine.
Wakefield has continued to defend his research and conclusions, claiming there was no fraud.
MMR does not cause encephalitis – but measles can
Encephalitis is a rare but serious condition in which the brain becomes inflamed. It can be life-threatening and requires urgent hospital treatment.
Around one in every 1,000 children who catch measles will develop encephalitis, which can lead to disability or death. Therefore, the MMR jab is essential for preventing this.
Dr Gill said MMR is a live-attenuated vaccine, meaning the virus has been made harmless so “the body can see it, but it can’t generate the illness in itself”.
Children do not require a heavy metal detox after the MMR jab
Content has circulated on social media urging parents to put their children through a “heavy metal detox” after having the MMR jab.
Various products are sold over the internet claiming to remove “heavy metals” and “parasites” from people’s bodies – with limited scientific evidence of their efficacy.
Whether or not certain products help with detoxification, there is no evidence having the MMR jab leads to a build-up of heavy metals.
In the UK, the vaccine contains a small amount of aluminium as an adjuvant to make it work more effectively. The NHS states that there is “no evidence that the levels of aluminium we come across every day increase the risk of conditions like dementia or autism”.
The MMR vaccine does not contain mercury, also known as thiomersal, the NHS said.
Are there any side effects to the MMR jab?
The vaccine is very safe with most side effects mild and short-lived.
According to the NHS, the area where the needle goes in can be sore for a few days and some babies may feel unwell or develop a high temperature around a week after the injection. This is a very mild form of measles and the symptoms are not infectious.
Around 1 in 50 children develop a mild form of mumps around a month after the vaccine which can last up to two days. Some adult women experience painful, stiff or swollen joints up to three weeks after the rubella jab which can last up to three days.
Rare side effects of the vaccine include bruise-like sports around two weeks after the jab, which is known as idiopathic thrombocytopenic purpura (ITP).
It is estimated that ITP develops in every 1 in 24,000 doses of the MMR vaccine given – but the risk of developing ITP from measles or rubella is much higher, according to the NHS. ITP usually gets better without treatment but it is advised to contact your GP if a rash appears.
A very small number of people can have a seizure six to 11 days after the MMR jab which is caused by a high temperature in response to the measles part of the vaccine.
This only happens in about one in every 1,000 doses given and MMR-related seizures are less frequent than fits related to a measles infection, the NHS states.
Serious allergic reactions to the jab are very rare and usually happen within minutes.
Let your doctor know if you or your child is allergic to gelatine or an antibiotic called neomycin, but the vaccine is safe for those with a severe egg allergy because it is grown on chick cells, not egg white or yolk.
There is a pork-free alternative called Priorix which is just as safe and effective as MMR VaxPro.
