Research and analysis

Laboratory confirmed cases of invasive meningococcal infection in England: April to June 2021

Updated 25 January 2022

Applies to England

In England, the national UK Health Security Agency (UKHSA) Meningococcal Reference Unit (MRU) confirmed 17 cases of invasive meningococcal disease (IMD) between April and June 2021. IMD cases were 41% lower during these 3 months compared to the 29 cases in the equivalent period in 2020 (table 1). This low number of confirmed cases was observed across all capsular groups.

The coronavirus (COVID-19) pandemic and the implementation of social distancing measures and lockdown across the UK from 23 March 2020 has had a significant impact on the spread and detection of other infections, including IMD.

The age distribution of meningococcal capsular groups causing IMD is summarised in table 2, with capsular group B (MenB) accounting for 88% (15 of 17) of all cases, followed by MenY (n=2, 12%).

There were 15 MenB cases confirmed between April and June 2021, 32% lower than in the equivalent period in 2020 (15 cases). There were no cases of MenW or MenC disease in this quarter, compared to 4 and 2 cases, respectively, confirmed in the equivalent period in 2020. There were 2 confirmed cases of MenY during this quarter of 2021, while no cases of MenY were reported in the same period in 2020 (table 1). There were no reported cases for capsular groups A, X or Z/E, or of ungrouped/ungroupable capsular group, during the reporting period in 2021.

Between April and June 2021, MenB was responsible for 2 cases of IMD in children aged less than 5 years of age. MenB also accounted for all 11 of the cases in individuals aged between 5 and 44 years and for 4 of the 6 cases in adults aged 45 years or more (table 2).

The introduction of a routine national MenB immunisation programme for infants was began with the immunisation of infants from 1 September 2015. Vaccine coverage estimates for infant MenB immunisation across England was 91.7% for 2 doses at 12 months of age and 88.5% for the booster dose by 24 months (evaluated between April and June 2021). The 2-dose infant MenB schedule has been shown to be highly effective in preventing MenB disease in infants.

Of the 2 MenW cases confirmed between April and June 2021, 1 case was reported an in adult aged 45-64 years of age, and 1 case in an adult aged 65 or older.

The earlier increase in MenW cases, which had been previously reported, led to the introduction of MenACWY conjugate vaccine to the national immunisation programme in England.

Targeted catch-up with MenACWY vaccine began in August 2015, at which time it also replaced the existing time-limited MenC ‘freshers’ vaccination programme. MenC vaccine was also directly substituted with MenACWY vaccine in the routine adolescent school programme (school year 9 or 10) from autumn 2015.

Coverage for young people routinely offered MenACWY vaccine in the 2019 to 2020 school year and evaluated up to the end of March 2021 was 53.8%, for year 9, and 87.0% for year 10.

The impact of the MenACWY teenage and the MenB infant vaccination programmes continues to be monitored. Early assessment of the infant MenB programme and MenACWY vaccination in the 2015 school leaver cohort have been published.

All teenage cohorts remain eligible for opportunistic MenACWY vaccination until their 25th birthday and it is important that these young people continue to be encouraged to be immunised. This is particularly important if they are entering higher education institutions where their risk of disease is known to be substantially higher than that of their peers.

Table 1: Invasive meningococcal disease in England by capsular group and laboratory testing method: April to June, 2020 and 2021

Capsular groups* Culture and PCR (2020) Culture and PCR (2021) Culture only (2020) Culture only (2021) PCR only (2020) PCR only (2021) Total (2020) Total (2021)
B 5 3 6 3 11 9 22 15
C 1 0 1 0 0 0 2 0
W 0 0 0 0 4 0 4 0
Y 0 0 0 1 0 1 0 2
Other** 0 0 0 0 1 0 1 0
Total 6 3 7 4 16 10 29 17

*No cases of group A, E, X and Z were confirmed during the periods summarised in the table.

**‘Other’ includes group E and ungrouped or ungroupable. (Ungroupable refers to invasive clinical meningococcal isolates that were non-groupable, while ungrouped cases refers to culture-negative but PCR screen (ctrA) positive and negative for the 4 genogroups [B, C, W and Y] routinely tested for).

Table 2. Invasive meningococcal disease in England by capsular group* and age group at diagnosis: April to June 2021

Age groups Capsular group B Capsular group C Capsular group W Capsular group Y Total number Total percentage
<1 year 1 0 0 0 1 5.9%
1 to 4 years 1 0 0 0 1 5.9%
5 to 9 years 3 0 0 0 0 17.6%
10 to 14 years 0 0 0 0 0 0%
15 to 19 years 4 0 0 0 4 23.5%
20 to 24 years 0 0 0 0 0 0%
25 to 44 years 2 0 0 0 2 11.8%
45 to 64 years 2 0 0 01 3 17.6%
65+ years 2 0 0 1 3 17.6%
Total 15 0 0 2 17

*No cases of group A, E, X or Z were confirmed during the periods summarised in the table.