Research and analysis

Laboratory confirmed cases of invasive meningococcal infection in England: October to December 2022

Updated 25 April 2024

Applies to England

In England, the national UK Health Security Agency (UKHSA) Meningococcal Reference Unit (MRU) confirmed 102 cases of invasive meningococcal disease (IMD) between October and December 2022 (table 1) compared to 65 and 19 cases of IMD in the equivalent periods in 2021 and 2020, respectively. However, IMD cases in October and December 2022 were 45% lower than in the same pre-pandemic period in 2019 when 186 cases were reported. Most confirmed meningococcal cases between October and December 2022 were due to capsular group B (MenB) disease whilst low numbers of cases were maintained 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. From July 2021, COVID-19 containment measures were withdrawn in England and overall case numbers have gradually increased.

The age distribution of meningococcal capsular groups causing IMD is summarised in table 2, with capsular group B (MenB) accounting for 88% (90 of 102) of all cases, followed by 5 capsular group Y (MenY) cases, 1 case each of capsular group C (MenC), capsular group W (MenW) and capsular group Z (MenZ), and 4 ungrouped or ungroupable cases.

The 90 MenB cases confirmed between October and December 2022 compares with 57 and 14 cases in 2021 and 2020, respectively. MenB cases in this quarter were 22% lower than the equivalent period in 2019 when 116 cases were reported.

Five cases of MenY were reported in this quarter in 2022 compared to 0 cases in 2021 and 2020, and 20 cases in 2019. One MenC case was reported in this quarter compared to 0, 1 and 9 cases in the equivalent periods in 2021, 2020 and 2019. One case of capsular MenW was reported in this quarter compared to 3, 3 and 37 cases reported for the same quarters in 2021, 2020 and 2019, respectively. No cases of group A, E or X were confirmed in this quarter in 2022. One case of MenZ was reported in this quarter, following the 2 previously reported (1 each in 2008 and in 2007).

Between October and December 2022, MenB was responsible for 93% (68 of 73 cases) of IMD cases in individuals aged under 25 years of age and 76% (22 of 29) of cases aged 25 years and over (table 2). Forty six per percent of all cases of invasive meningococcal disease, and 48% of all MenB cases, arose in young people aged 15 to 24 years during this time.

The MenC, MenW and MenZ cases confirmed between October and December 2022, and 3 of the MenY cases, were in adults aged 25 years and older; 1 MenW case was in a child aged between 5 and 9 years, and 1 in an adult aged between 20 and 24.

Vaccination

The introduction of a routine national MenB immunisation programme for infants began with the immunisation of infants from 1 September 2015. Vaccine coverage estimates for infant MenB immunisation across England was 91.6% for 2 doses at 12 months of age and 87.8.1% for the booster dose by 24 months of age – evaluated between October and December 202 (1). The 2-dose infant MenB schedule has been shown to be highly effective in preventing MenB disease in infants and toddlers (2).

The earlier increase in MenW cases, which had been previously reported in 2015, led to the introduction of MenACWY conjugate vaccine 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 2020 to 2021 school year and evaluated up to the end of August 2021 was 69.2%, in school year 9, and 79.6% in school year 10 (3). Local arrangements are being made for catch-up for the cohorts who missed vaccination at school during periods when COVID-19 control measures were in place.

The impact of the MenACWY teenage and the MenB infant vaccination programmes continues to be monitored. Early assessments of the infant MenB programme (2,4) and MenACWY vaccination in the 2015 school leaver cohort have been published (5,6).

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 (7).

Table 1. Invasive meningococcal disease in England by capsular group and laboratory testing method: October and December, 2021 and 2022

Capsular groups*	Culture and PCR (2021)	Culture and PCR (2022)	Culture only (2021)	Culture only (2022)	PCR only (2021)	PCR only (2022)	Total (2021)	Total (2022)
B	16	18	16	21	25	51	57	90
C	0	0	0	0	0	1	0	1
W	0	0	3	1	0	0	3	1
Y	0	0	0	3	0	2	0	5
Other**	1	1	2	1	2	3	5	5
Total	17	19	21	26	27	57	65	102

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

**‘Other’ includes E, Z 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: October and December 2022

Age groups	Capsular group B	Capsular group C	Capsular group W	Capsular group Y	Capsular group Other**	Total number	Total percentage
<1 year	8	0	0	0	0	8	7.8%
1 to 4 years	8	0	0	0	0	8	7.8%
5 to 9 years	4	0	0	1	0	5	4.9%
10 to 14 years	5	0	0	0	0	5	4.9%
15 to 19 years	33	0	0	0	2	35	34.3%
20 to 24 years	10	0	0	1	1	12	11.8%
25 to 44 years	9	1	0	0	0	10	9.8%
45 to 64 years	7	0	1	1	1	10	9.8%
65+ years	6	0	0	2	1	9	8.8%
Total	90	1	1	5	5	102	–

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

**‘Other’ includes group Z 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).

References

1. Health Protection Report volume 16 issue 13 (20 December 2022) ‘Quarterly vaccination coverage statistics for children aged up to 5 years in the UK (COVER programme)’.

2. Ladhani S and others (2020) ‘Vaccination of Infants with Meningococcal Group B Vaccine (4CMenB) in England’, the New England Journal of Medicine: volume 382 number 4.

3. Health Protection Report volume 17 issue 5 (24 April 2023) ‘Meningococcal ACWY (MenACWY) vaccine coverage for the NHS adolescent vaccination programme in England, academic year 2020 to 2021’.

4. Health Protection Report volume 10 issue 37 (28 October 2016) ‘Impact of MenB vaccination programme in England’.

5. Campbell H and others (2017) ‘Emergency Meningococcal ACWY Vaccination Program for Teenagers to Control Group W Meningococcal Disease, England, 2015 to 2016’, Emerging Infectious Disease, volume 23 number 7.

6. Campbell H and others (2022). ‘Impact of an adolescent meningococcal ACWY immunisation programme to control a national outbreak of group W meningococcal disease in England: a national surveillance and modelling study’, Lancet Child Adolescent Health: volume 6 issue 2.

7. Mandal S and others (2017). ‘Risk of invasive meningococcal disease in university students in England and optimal strategies for protection using MenACWY vaccine’, Vaccine: volume 35 issue 43.