The epidemiology of infectious diseases must consider a number of aspects of the
disease along with its control and prevention, as these will ultimately alter disease
incidence, trends and distribution within a population. For many infectious diseases, the
greatest medical tool available to combat them is vaccination. Historically, the UK has
successfully controlled invasive meningococcal disease through vaccination. As a
result, the majority of disease seen in today’s epidemiological landscape is caused by a
previously non-preventable form. Monitoring the epidemiology of invasive
meningococcal disease relies on strong surveillance systems which in turn, allow for the
evaluation of vaccination programmes. An understanding of the relationship between a
vaccination programme and its effect on the epidemiology of the targeted disease is
vital for assessing the success of a programme and gives insight into how these
programmes may be improved.
This thesis presents eight studies, presented in three sections, that used
epidemiological data to demonstrate the success of the national infant MenB
vaccination programme in England. The studies presented have provided baseline
estimates of the burden of invasive meningococcal disease (IMD) and the predicted
strain coverage of the 4CMenB vaccine against circulating strains in England prior to
the vaccine’s national introduction in September 2015. These studies also provided the
first ever estimates of 4CMenB’s vaccine effectiveness at a reduced vaccination
schedule, to that used for licensure, along with the impact on MenB disease in the
group with the highest incidence of disease, children under the age of five, who were
targeted with the vaccine. Further, these studies looked at the epidemiology and trends
of disease in vulnerable populations in England, highlighting the markedly increased risk
in a young person on long term complement inhibitor therapy and raising awareness of
the increased risk in cases who initially present with a less common presentation and its
implications for the public health and clinical management of these cases. Finally, these
studies explored cases of IMD in pregnant women in England over a four-year period
and showed that while disease during pregnancy can be severe, there was an unusual
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finding of a significantly decreased risk of IMD in pregnant women compared to nonpregnant women of a similar age.
The combined findings of these studies show the success of the first nationally funded
4CMenB immunisation programme and its subsequent effects on the epidemiology of
invasive meningococcal disease in England
