‘Concerning gaps’ in measles immunity revealed among hospital staff

8th July 2024

Some secondary healthcare staff may be putting themselves at risk of contracting measles and spreading the virus to others by opting out of vaccination, a recent medical journal correspondence has suggested.

In a letter published in The Lancet, researchers from the University of Birmingham highlighted the ‘concerning gap’ in measles immunity among healthcare workers in the UK, with as many as one in five not fully immunised against the infection.

The risk is particularly high for younger workers born after 1998, where vaccine hesitancy leaves them vulnerable to infection and may facilitate the spread of the infection.

The researchers stated that all healthcare workers who come in contact with patients should have their immune status assessed. If they are found not to have immunity, they should be offered a measles-containing vaccination, as recommended in the national measles guidelines.

In January 2024, the UK Health Security Agency declared the rapid increase in measles cases a national incident. The measles vaccination programme has successfully reduced measles transmission in the UK in the past. However, erroneous concerns about the safety of the MMR vaccine undermined this effort, resulting in a recent rise in infections.

Using data from the VIBRANT study, which looks at the immune response of healthcare workers across the UK and is a substudy of the UK SIREN study, the researchers examined the immune system of 200 healthcare workers recruited from NHS hospitals across the UK. The cohort had a median age of 51 and was 81% female.

An additional, younger cohort with a median age of 42 was also examined. The second cohort was recruited from the CoCo study and involved 413 healthcare workers, three-quarters of whom were female.

Using the anti-measles virus ELISA (IgG) – a laboratory test that can detect and measure the presence of IgG antibodies against the measles virus – the researchers determined levels of protection against measles, alongside clinical and demographic characteristics of the participants.

In both cohorts, the researchers found that measles immunity is currently suboptimal. Increasing age was linked with better immunological protection, with older healthcare workers having higher levels of immunity than younger colleagues. For every increasing year of age, the researchers found the odds ratio of returning a positive IgG result increased by 1.06.

In the first cohort of 200 participants, six (3%) had no measles immunity and eight (4%) had unclear results, meaning immunity levels could not be determined. In the second cohort of 415 younger workers, 54 (13%) were negative for measles antibodies and 31 (8%) had equivocal results.

Professor Alex Richter, professor and honorary consultant in clinical immunology at the University of Birmingham and lead author of the paper, said: ‘Our new research highlights a concerning gap in measles immunity among healthcare workers, who may unwittingly be putting themselves and vulnerable populations at avoidable risk.’

She added: ‘Healthcare workers in patient-facing roles, especially those working with children and immune-compromised individuals, are at risk of contracting and spreading measles if they are not fully immune to measles.’

The researchers suggest the fall in immunity is partly due to the success of the measles vaccination programme. With so few measles cases in the last 20 years, people who remained unvaccinated were unlikely to acquire immunity through infection. In addition, concerns about the MMR vaccine, which emerged in 1998, could account for the compromised vaccine uptake in those born after this time, the researchers added.

Dr Antonia Ho, clinical senior lecturer and consultant in infectious diseases at the MRC-University of Glasgow Centre for Virus Research and first author of the letter, advised that healthcare workers should check their vaccine history if uncertain and be offered vaccination.

She added: ‘Vaccination remains the most effective method of controlling measles. Therefore, every effort should be made to support health care workers, who are on the front lines of patient care, to ensure they are protected against measles to safeguard themselves and their patients.’

A version of this article was originally published by our sister publication Nursing in Practice.

Check MMR vaccine records as measles cases rise, UKHSA urges parents

4th May 2023

Public health officials are urging parents to check their children are up to date with MMR vaccinations after signs of a rise in measles cases.

The latest figures from 1 January to 20 April 2023 show 49 cases of measles compared to 54 cases in the whole of 2022, the UK Health Security Agency (UKHSA) said.

Most of the cases have been reported in London, although some cases have been picked up across the country and some are linked to travel abroad, the data shows.

It follows a drop in the number of children who have had one or both doses of the MMR in recent years.

The uptake for the first dose of the MMR vaccination at two years in England is currently 89% and uptake of two doses by five years is 85% – both well below the 95% target set by the World Health Organization (WHO) to achieve and maintain elimination, the UKHSA said.

Pandemic impact on MMR

Routine childhood vaccinations fell globally during the pandemic and measles is now circulating in many countries around the world with WHO officials warning that Europe is likely to see a resurgence unless countries catch-up children who missed out.

Parents of young children and teenagers are being asked to check they are up to date with their MMR vaccines, particularly before they travel this summer or attend festivals and to contact their GP practice if they believe they have missed a dose.

Dr Vanessa Saliba, consultant epidemiologist at UKHSA, said: ‘We are calling on all parents and guardians to make sure their children are up to date with their two MMR doses.

‘It’s never too late to catch up, and you can get the MMR vaccine for free on the NHS whatever your age.’

She added: ‘Measles spreads very easily and can lead to complications that require a stay in hospital and on rare occasions can cause lifelong disability or death, so it is very concerning to see cases starting to pick up this year.’

‘Uptake falls, infections rise‘

Figures published in September last year showed no routine childhood vaccination met the 95% uptake target last year in England. But there has been particularly concern about MMR with catch up campaigns already launched last autumn.

NHS director of vaccinations and screening, Steve Russell, said: ‘The MMR vaccine has helped prevent the development of potentially life-threatening illness among millions, and it is clear that when uptake falls, infections rise, so I strongly urge parents to review the status of their child’s vaccinations so they can keep them and others protected from measles, mumps and rubella.’

Last month, UKHSA’s director of public health programmes Dr Mary Ramsay said that workload around vaccine delivery ‘fell purely onto general practice’ in the past decade due to the fragmentation of the NHS.

This news story was originally published by our sister publication Pulse.