Recently the Australian government announced that from April 2019 the meningococcal vaccine Nimenrix will be available free to teenagers aged 14-19. This will prove to be a significant public health measure against Invasive Meningococcal Disease (IMD).
Nimenrix is a quadrivalent vaccine protecting against 4 of the 13 serogroups of the bacterium Neisseria meningitidis. The four serogroups are A, C, W and Y. The vaccine Bexsero protects against serogroup B and is presently the subject of a South Australian study. The manufacturers of the vaccine, GlaxoSmithKline have confirmed they will seek to have Bexsero listed on the National Immunisation Program once they have the study results. The ACWY vaccine has been freely available to 12 month olds since July 1st, 2018. Of these five primary strains of meningococcal disease, B and W serogroups are the most common.
The incidence of meningococcal disease and the serogroup responsible fluctuates over time. According to the National Centre for Immunisation Research and Surveillance (NCIRS), serogroup B (MenB) was the most common cause of IMD from 2006 to 2015. Over this period MenB accounted for 63% to 88% of annual notified cases where a serogroup was identified. An NCIRS fact sheet notes that since 2013 serogroup W (MenW) has increasingly caused IMD.
In that year 17.4% or 17 cases with an identified serogroup were responsible for the disease. By 2017 MenW was identified as responsible for 38.1% or 139 cases. It is also clinically interesting that the NCIRS have reported, “many of the MenW cases have been due to a single clone of meningococcus, the ST-11 strain type”. This suggests sustained person to person transmission. MenW appears to have a higher fatality rate (9.3%) than MenB (5%).
With serogroup Y there has been a “smaller but notable” increase. In 2014 there were 7.4% or 12 cases of those with an identified serogroup, increasing to 20.5% or 75 cases in 2017. IMD due to serogroup Y is more common in older Australians. 61% of the 75 notified cases in 2017 were in adults ≥ 45 years or older. The decrease in cases due to serogroup C (MenC) is an indication of the efficacy of immunisation programmes.
The MenC conjugate vaccination programme began in 2003. The number of MenC cases with an identified serogroup was 225 in 2002, falling to 14 (3.8%) in 2017. The NCIRS observe that, “serogroup A disease remains rare in Australia”. Nonetheless overall meningococcal disease and death from different serogroups has increased in recent years.
- 2015: 182 cases, 12 fatalities
- 2016: 252 cases, 11 fatalities
- 2017: 382 cases, 28 fatalities
The Fairfax article was published at 12.00am on September 25th and noted that there had been ten fatalities from meningococcal “so far this year”. A little over 44 hours later at 8.07pm on September 26th the Moree Champion reported;
Laboratory tests have confirmed meningococcal disease as the cause of death in a 25 year old woman in the New England region. The young woman collapsed at home on Saturday, September 22 and was taken to hospital by ambulance, but was unable to be revived.
Meningococcal disease can kill within 24 hours if not treated in time. The audio below is from Meningococcal Australia and addresses important points regarding infection, symptoms, prevention and treatment.
- Or download mp3 file here © Meningococcal Australia
The Meningococcal Australia website notes;
10% of those infected will die, and around 20% will have permanent disabilities — ranging from learning difficulties, sight and hearing problems, to liver and kidney failure, loss of fingers, toes and limbs and scarring caused by skin grafts.
It is important to access reputable information with respect to diseases such as Invasive Meningococcal Disease. IMD from the five primary serogroups A, C, W, Y and B can be prevented by vaccination. This makes it a target for misinformation from the anti-vaccination lobby. In Australia the most vocal group is the Australian Vaccination-risks Network, or AVN.
Meningococcal bacteria can live harmlessly in the throat and nose in 20% of people and IMD is one of the less common bacterial diseases. Antivaccinationists use this information to wrongly assert there is no need to be vaccinated. Yet the reality is that in cases of meningococcal disease the bacteria enter the bloodstream and multiply rapidly, causing septicaemia and damage to blood vessel walls. This leads to bleeding into skin tissue producing the dark purple rash associated with meningococcal disease.
Bacterial meningitis caused by meningococcal disease is the most dangerous type of meningitis. Meningitis is a serious inflammation of the meninges – the lining of the spinal cord and brain. Thus the argument that humans “naturally” carry meningococcal bacteria and should avoid vaccination is based on deceptive reasoning and is dangerously misleading.
Vaccines are demonstrably very safe. The testing of vaccines before approval for use in Australia can take over a decade. Their ingredients are well understood and are themselves tested for safety.
The introduction of the quadrivalent meningococcal vaccine Nimenrix is a positive for Australian public health.