Recently, the HSE announced that there had been a spike in bacterial meningitis cases in Ireland over the Christmas period. There was widespread and continued media coverage of the announcements. This has led many concerned parents wondering if they need to get their kids vaccinated over and above what is contained within the universal primary childhood immunisation programme.
To answer this question it is important to understand what meningitis is and what causes it. Meningitis is an inflammation of the lining around the brain and spinal cord and there are two main causes- bacterial and viral meningitis.
Viral meningitis is commoner, usually occurs in young kids, and is milder and rarely fatal. It can result in severe symptoms but people unlucky enough to get it usually recover quickly. Enteroviruses, of which there are many strains, are the most frequent cause. We have no vaccines against, or specific treatment for, enteroviruses.
Bacterial meningitis, although rarer, is much more serious. It may result in septicaemia (“blood poisoning”) as well as meningitis. It can leave permanent brain damage and can be fatal, sometimes within hours. However, caught early (which is the key), it is usually curable. Adults with bacterial meningitis usually develop a headache, high temperatures, neck stiffness, aversion to light and sometimes a rash. It needs to be suspected in any adult who is unusually unwell or already unwell and getting worse, and especially if there is a change in mental status. “Typical” symptoms are not common in infants and young children. In these, any unusual unwellness or deteriorating symptoms need to be urgently evaluated. Don’t ignore your intuition! Do not wait until a rash appears- once the typical rash (i.e. rash that doesn’t disappear when you spread the skin or put a glass on it) appears, the illness is very serious and possibly beyond recovery.
N. meningitidis, of which there are several strains (A, B, C, W and Y), is the commonest cause of bacterial meningitis. In Ireland, strains B (MenB) and C (MenC) have always been the most common. After the introduction of the MenC vaccine in 2000, and in conjunction with a “catch up” programme in which the MenC vaccine was offered for free to everyone up to the age of 23, the number of MenC cases fell dramatically in Ireland- from 139 cases in 2000 to just 6 cases in 2014. The number of MenB cases has also been declining over the years, with the number of cases significantly falling even before the introduction of the MenB vaccine in October 2016. From around 300 notified MenB cases in Ireland 1999, there were less than 50 notifications in 2015. There has however been a slight increase in the case numbers due to both strains in recent times and, although the overall numbers have reduced significantly, they still remain the most predominant.
Unlike with the MenC vaccination strategy, a catch-up programme for the MenB vaccine has not yet been introduced for children born before October 2016. Parents have to pay for it in these kids if they want to avail of it and the 2 dose vaccination schedule costs about 300 euro in total. The likely reason for a national catch-up programme not to have been introduced to date is cost-effectiveness. Given the rarity of the condition and the fact that the burden of disease is generally highest in children under the age of 1, a catch-up programme for older children was probably not deemed to have been worth it.
So what was the story with the recent media announcements? Eleven cases of meningococcal meningitis were reported in Ireland between 24/12/2018 and 06/01/2019. This compares with five cases during the same period last year. As of 14/01/2019 (as per the latest national update), there had been no other confirmed cases. Among the eleven cases, different age groups were involved, different meningococcal strains were reported, different parts of the country reported the cases and there were no known links found between the cases involved. Sadly, three died but none of these were caused by strains that are covered by the vaccines in the current universal primary childhood immunisation programme (i.e. the strains were not B or C). This was not an outbreak; it probably simply represented the fact that most cases of meningitis occur in Winter and early Spring. It does remind us however of the ongoing need for vigilance for signs of meningitis and to ensure that everyone is appropriately vaccinated and up-to-date with the immunisation programme.
So should you vaccinate your child against MenB if they were born before October 1st 2016? The recent spike in cases has not yet caused the HSE to change their stance on the need for a free catch-up programme. There isn’t a national recommendation either that you should look to avail of it privately. This isn’t surprising given the strains involved in the recent media-reported cases. The current HSE advice is for parents “to ensure their children are fully vaccinated, as per the State’s Universal Immunisation Programme”.
I would certainly agree with this advice. However, MenB was thought to have accounted for around 50% of the notified meningococcal cases in 2018 (data for first 3 quarters of the year). Given the seriousness of MenB meningitis, the availability of a licensed vaccine with reasonable safety and efficacy (the vaccine is thought to be around 88% effective), and the fact that the 1-4 and the 15-24 age groups are the next most common for MenB infections to occur in (other than < 1 year old), I would advise that parents who can afford to do so should at least have a discussion with their GP about the pros and cons of getting it for their particular child. My own tendency would be to recommend it if you can afford it. For any unvaccinated child who goes on to develop MenB infection, it certainly would have been cost-effective at an individual level for them to have been vaccinated in the first place!