MMR jab used to prevent measles, mumps and rubella could help protect against COVID-19

The MMR jab used against measles, mumps and rubella could help protect against COVID-19 by boosting the immune system, lowering the risk of deadly symptoms.

According to US experts, booster vaccinations should be given to vulnerable individuals — including hospital and care home workers — first, then the public.

Research has indicated that it stops severe inflammation, or sepsis — without presenting any risk of side effects.

‘Vaccination with the MMR jab may be especially beneficial for health care workers who might easily be exposed to COVID-19, said paper author and immunologist Paul Fidel of the Louisiana State University.

‘Live attenuated vaccines seemingly have some non-specific benefits as well as immunity to the target pathogen,’ Dr Fidel explained.

‘A clinical trial with MMR in high-risk populations may provide a low-risk, high-reward preventive measure in saving lives during the pandemic.’ 

Recent events have provided indications that the hypothesis might be applicable in practice, Dr Fidel said. 

In the US Navy, the MMR jab is given to all recruits — and in an outbreak among the crew of the aircraft carrier the USS Roosevelt, milder symptoms were seen in 955 of the sailors who tested positive for COVID-19, with only one needing hospitalisation. 

In addition, epidemiological data has revealed an association between areas where people are routinely given the MMR vaccine and reduced COVID-19 death rates.

The jab is typically given to all infants at the age of around nine-months-old.

‘While we are conducting the clinical trials, I don’t think it is going to hurt anybody to have an MMR vaccine that would protect against the measles, mumps, and rubella with this potential added benefit of helping against COVID-19,’ Dr Fidel said.

Past research by the team demonstrated that a live attenuated fungal vaccine improved protection against lethal sepsis.

This was fuelled by the immune system’s long-lived ‘myeloid-derived suppressor cells’ — or MDSCs — that have been found to stop inflammation and death in animal tests.

The MMR jab should be able to induce MDSCs that inhibit or reduce the severe lung inflammation and sepsis associated with COVID-19 mortality, the team said.

According to US experts, the MMR vaccine should be given to vulnerable individuals — including hospital and care home workers — first, then the general public. Research has indicated that it stops severe inflammation, or sepsis — without side effects

Vaccines trigger non-specific immune reactions by training white blood cells in the bone marrow to function more effectively against invaders.

The fact that children have typically been recently exposed to MMR and other vaccines that prime MDSCs to limit inflammation and sepsis could explain why kids do not appear to be as severely affected by COVID-19. 

‘If adults got the MMR as a child they likely still have some level of antibodies against measles, mumps, and rubella, but probably not the myeloid-derived suppressor cells,’ said Dr Fidel.

‘While the MDSCs are long-lived, they are not life-long cells. So, a booster MMR would enhance the antibodies to measles, mumps, and rubella and re-initiate the MDSCs.’

‘We would hope that the MDSCs induced by the MMR would have a fairly good life-span to get through the critical time of the pandemic.’

The researchers have been awarded a grant to test the efficacy of MMR directly in rhesus monkeys infected with COVID-19 — which, if successful, could lead to a clinical trial.

A recent study by scientists at Cambridge University found that the key proteins in measles, mumps and rubella viruses have similarities with those in COVID-19 — with that team also suggesting the MMR jab could help fight the pandemic.