Professor Ray Borrow, Head of Vaccine Evaluation Unit, Public Health England, Manchester

1. Issues in evaluating the
impact of a new
meningococcal B vaccine
Ray Borrow
Professor of Vaccine Preventable Diseases,
Vaccine Evaluation Unit,
Public Health England,
Manchester Royal Infirmary,
Manchester, UK
ray.borrow@phe.gov.uk

2. UK and the serogroup B
challenge, introduction
• MenB polysaccharide is polysialic acid, a compound identical to that found on
the surface of human neuronal cells.
• Consequently;
(i) Poorly immunogenic.
(ii) Potential to induce an autoimmune response.
• Use subcapsular antigens, which are;
(i) Surface exposed.
(ii) Conserved.
(iii) Induce bactericidal activity.

3. http://www.inpharm.com/news/101223/novartis-meningococcal-vaccine-bexsero
• Bexsero (previously known as 4CMenB or rMenB+OMV) contains 4 main
antigens.
• Three recombinant proteins discovered by genome mining/reverse vaccinology
combined with OMV from the New Zealand outbreak strain (NZ 98/254).
Novartis investigational MenB
4CMenB vaccine (Bexsero®
)
PorA
(presented as
part of an OMV)
NadAfHBP 1 NHBA

4. Bexsero (Novartis)
clinical program
• Phase 3 studies in infant, toddlers and adolescents
complete.
• Over 5000 infants/toddlers and 2000
adolescents/adults vaccinated.
• Acceptable safety and tolerability profile in all age groups.
• Co-administered infant vaccines elicit expected immune
responses when given with Bexsero.
Bai X, Findlow J & Borrow R. Expert Opin Biol Ther 2011;11:969-85.

5. Bexsero: Proposed immunisation
schedules by population
*The safety and immunogenicity of 4CMenB in individuals older than 50 years have not been studied.
The safety and immunogenicity of 4CMenB in individuals older than 50 years have not been studied.
The proposed UK infant immunisation schedule is a primary series
at 2,3 and 4 months with a booster at 12 months of age
Information provided by Novartis Vaccines

6. Potential UK schedules
Infant schedule?
Infant schedule and catch-up?
Not recommended?
Infant & adolescent schedule?
Infant schedule, catch-up and adolescent schedule?
Adolescent schedule?

7. Predicting strain coverage
Polysaccharide based vaccines
•Simply calculated as the proportion of isolates with given polysaccharide.
•Genotypic typing information alone is insufficient to calculate coverage.
 Pfizer and Novartis have both developed assays to determine coverage
of their respective vaccines.
Subcapsular vaccines
•More complicated due to:
 Multiple protein variants (vaccine induced antibody is not equally cross-
reactive against all variants).
 Protein expression differs between isolates.

8. Meningococcal Antigen
Typing System (MATS)
concept (Novartis)
Are any of the Bexsero components in
the circulating strains:
(i) expressed to a sufficient degree,
and
(ii) similar enough to the antigens in
the vaccine such that the
antibodies generated by Bexsero
will kill the bacteria?
MATS determines the minimum amount of recognisable antigen
needed to result in bacterial killing for each of the four
components

9. Meningococcal Antigen
Typing System (MATS)
Donnelly J et al. PNAS. 2010;107:19490-5.

10. Using MATS to predict whether strains are
covered by 4CMenB. Positive Bactericidal
Thresholds (PBT): Example - fHbp
10
 Shown are the 36 fHbp
expressing strains in which
NadA, NHBA and PorA are
either absent or mismatched
Donnelly J et al. PNAS. 2010;107:19490-5.

11. Killed in SBA: infant serum pool titer ≥ 8
Not killed in SBA
 Serum pools from 13-month-olds
immunised with 4CMenB were
tested in SBA against diverse
MenB strains.
 The PBT is defined as the value
above which ≥ 80% strains are
killed in SBA, maximising
statistical predictive power.
 Separate PBT for each antigen
based on corresponding subsets
of strains with 3 of 4 antigens
absent or mismatched.
Donnelly J et al. PNAS. 2010;107:19490-5.
Using MATS to predict whether strains are
covered by 4CMenB. Positive Bactericidal
Thresholds (PBT): Example - fHbp

12. Coverage by the PorA (OMV) component of the vaccine
is determined by conventional typing, it presence by
either serotyping or genotyping of PorA P1.4
PorA coverage
PorA P1.4 (presented as
part of an OMV)
37 different variants of P1.4 (P1.4, P1.4-1 etc)
From PorA sequenced case isolates submitted
to PHE MRU (1985 to 2008), 492 belonged to
P1.4 family.
P1.4 n = 478 (97.2%) All mab +ve
P1.4-1 n = 13 (2.6%) All mab -ve
P1.4-5 n = 1 (0.2%) Mab -ve

13. Distribution of MATS relative potency for fHbp
among different invasive MenB strains sorted
by fHbp variant and peptide: Europe 2007/8
PBT with 95% CI
Box and whiskers
denote quartile
ranges for each
distribution.
VARIANT 1 VARIANT 2 VARIANT 3
Family B Family A
Strains with fHbp peptides belonging to variant 1 generally had MATS RPs > PBT.
Strains with fHbp belonging to variants 2 and 3 had MATS RPs < PBT.
Vogel U et al. Lancet Infect Dis 2013;13:416-25.

14. Distribution of MATS relative potency for NHBA
among different invasive MenB strains sorted
by NHBA peptide: Europe 2007/8
PBT with 95% CI
Box and whiskers
denote quartile
ranges for each
distribution.
Within each NHBA peptide variant, MATS RPs varied over a 5 to 10-fold range indicating significant
variation in the level of NHBA expression among isolates harboring the same peptide.
Vogel U et al. Lancet Infect Dis 2013;13:416-25.

15. 0
27%
1
23%
2
34%
3
16%
Predicted coverage of Bexsero against English and Welsh
MenB isolates 2007/08 (no of antigens)*
*> MATS PBT for fHBP, NadA and NHBA, and homologous serotype for PorA.
Overall
coverage
estimate of
72.9%
Novartis Meningococcal
Antigen Typing System (MATS)
N=535
Vogel U et al. Lancet Infect Dis 2013;13:416-25.
1
23%
0
27%
2
34%
3
16%

16. 1433 1343
1107
975 981 909
753
568 489
385 391 339 349 271 249 252 276 231 144
5 148
482
576
753
638
526
398
389
325 306
274 252
309
198 210 185
174
96
13
376
888 874
1070
1108
1065
804
738
603 721
548
697 654
596
469 498
379
203
0
500
1000
1500
2000
2500
3000
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 20122013 (To June 13)
noofcases
PCR only
Culture and PCR
Culture only
Laboratory Confirmed Cases of
Meningococcal Disease, England &
Wales - by Calendar Year
50% PCR
only
confirmed
PHE MRU unpublished data

18. If no systemic isolate?
•Cannot determine expression from non-culture PCR-based
techniques.
•Need an isolate.
•Use nasopharyngeal isolates where available.

19. Nasopharyngeal isolates
from cases
Cartwright KA, Jones DM. Value of throat swabs from index cases of
meningococcal meningitis. J Clin Pathol 1990;43:438.

20. Nasopharyngeal isolates
from cases
NICE guides do not stipulate
submission of nasopharyngeal
isolates from cases.
HPZone* prompts for collection of throat swabs for
suspected meningococcal cases.
* HPZone is a web based support tool designed to provide staff at local Health Protection Units with timely
& comprehensive information on cases, outbreaks, incidents and threats.

21. Typing data currently generated
•For cultures: Meningitis Research Foundation whole genome project.
2010/11 514 isolates
2011/12 417 isolates
•For non-culture:
•PorA
•fHbp

22. Culture vs non-culture genotyping: PorA
7-2, 4, 37 22, 14, 36
22, 9, 35-1 19-1, 15-11, 36
18-1, 3, 38 19, 15, 36
17-1, 23, 37 22, 14-6, 36-2
12-1, 9, 35-1 18-7, 9, 35-1
7, 16, 35 7, 30, 38
19-2, 13-1, 36 5-1, 10-8, 36-2
18-1, 14, 36 5, 2, 36-2
17, 16-3, 36 21, 16, 37-1
5-1, 2-2, 36-2 7-1, 1, 35-1
12-1, 16, 37-1 18-1, 34, 38
19-1, 3-5, 38 7-2, 13-1, 35-1
Other =1
Group B case isolates
2012 (Jan-Nov)
Total 223
7-2, 4, 37 22, 14, 36
22, 9, 35-1 19-1, 15-11, 36
np 18-1, 3, 38
7, 30, 38 19, 15, 36
7-1, 1, 35-1 17-1, 23, 37
5, 2, 36-2 21, 16, 37-1
22, 14-6, 36-2 5-1, 10-1, 36-2
22, 9, ? 5-1, 10-8, 36-2
7, 16, 35 17, 16-3, 36
22, 4, 37 5-1, 2-2, 36-2
12-1, 16, 37-1 18-7, 9, 35-1
other
Group B PCR+ve only
positive cases
2012 (Jan-Oct)
Total 216

23. Non-culture genotyping: fHbp
•To provide a complete picture of fHbp diversity and distribution, a
PCR-based sequencing assay has been developed to amplify and
sequence the meningococcal DNA within non-culture confirmed
samples.
•A nested-PCR protocol consisting of two consecutive PCR rounds is
used to increase the sensitivity and specificity of the assay.
•This assay is being used in an ongoing project to determine the fHbp
allele of all non-culture cases between 2011-2015.

24. Approximately half of 2011 samples have been sequenced.
The non-culture profile generally reflects that of the cultured isolates.
There is noticeably lower
incidence of fHbp peptides
2.22 (A10) and 2.25 (A15) in
the non-culture samples.
These peptide variants are
associated with groups W
and Y, respectively.
Interim non-culture fHbp results
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
2011 Culture Isolates 2011 Non-Culture (244
samples)
Other
37
47
21
22
16
45
1
19
14
25
15
13
4
Jan to June Jan to May, Nov to Dec

25. B
76.3%
Y
14.8% W
5.1% C
2.5%
other
1.0%
cnl/NG
0.4%
2010/11 isolates
B
83.8%
Y
8.3%
W
3.5%
C
2.3%
other
0.2%
cnl/NG
2.0%
2010/11 allCulture only Culture/non-culture
Capsular group for culture only
proven versus culture/non-culture
laboratory confirmed cases, 2010/11
Lucidarme J et al. The Meningitis Research Foundation Meningococcal Genome Library.
Neisserialvaccines2013, Varadero, Cuba, May 2013.

26. 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
clonal complex (n)
NK
>66
26-65
16-25
6-15
3-5
2
1
<1
Y W
Age (years)
Clonal complex versus age group
Lucidarme J et al. The Meningitis Research Foundation Meningococcal Genome Library.
Neisserialvaccines2013, Varadero, Cuba, May 2013.

27. Post-licensure studies of
meningococcal serogroup B
vaccine, Bexsero®
•Descriptive studies
•Effectiveness studies

28. Descriptive studies
•Summary of the epidemiology of meningococcal disease, by
vaccination status, age, etc.
•Focus on the epidemiology not only of meningococcal
serogroup B, but, also include other serogroups.
- evaluate cross protection against other serogroups.
- any capsule replacement after introduction of the
vaccine.

29. Effectiveness studies
•Analyses for effectiveness of 4CMenB will be performed prospectively
eg by the screening method.
•The screening method has been used to successfully assess
meningococcal serogroup C conjugate vaccine1, Haemophilus
influenzae type b conjugate vaccine2 , and influenza vaccine3
effectiveness in the UK.
•The screening method is based on a comparison of the proportion
vaccinated among the cases and the population and control is achieved
by using an estimate of vaccine coverage.
•If the screening method is inapplicable then a case control method
would be used.
1. Trotter CL et al. Lancet 2004;364:365-7.
2. Ramsay ME et al. J Infect Dis 2003;188:481-5.
3. Fleming DM et al. J Epidemiol Community Health 2010;64:1062-7.

30. A case of N. meningitidis is defined by culture of N.
meningitidis or identification of meningococcal DNA from a
normally sterile site.
Cases can be further classified as:
1) A case of serogroup B N. meningitidis is defined as isolation
of serogroup B N. meningitidis or positive capsular group B
specific PCR from a normally sterile site.
Definitions - 1

31. Definitions - 2
2) A serogroup B Bexsero-vaccine-type confirmed case can
be defined as either:
 Isolation of serogroup B N. meningitidis with at least one vaccine antigen above
the positive bactericidal threshold (PBT) as measured by the MATS assay from a
normally sterile site, or
Positive for meningococcal DNA and capsular group B specific PCR on a
normally sterile site plus isolation from a throat swab of serogroup B N.
meningitidis with at least one vaccine antigen above the PBT as measured by the
MATS assay, or
Positive for meningococcal DNA and capsular group B specific PCR on a
normally sterile site and PorA P1.4 identified on genosubtyping.

32. 3) Non-serogroup B Bexsero-vaccine-type confirmed case is
defined as either:
 Isolation of non-B serogroup N. meningitidis with at least one vaccine antigen
above the PBT as measured by the MATS assay from a normally sterile site, or
Positive for meningococcal DNA and non-B serogroup specific PCR on a
normally sterile site plus isolation from a throat swab of the same serogroup N.
meningitidis with at least one vaccine antigen above the PBT as measured by
the MATS assay, or
 Positive for meningococcal DNA and non-B serogroup specific PCR on a
normally sterile site and PorA P1.4 identified on genosubtyping.
Definitions - 3

33. Definition of a Bexsero
vaccine failure
A confirmed case as defined above and …
… the confirmation that the patient was age appropriately
and fully vaccinated as recommended and with 1 month
delay for a full effect of the immunisation.

34. Clinical case of
N. meningitidis
Reported to PHE MRU
Serogroup B
vaccine-type
Serogroup B
Non-serogroup B
vaccine-type
No
N. meningitidis
confirmation
PCR only
confirmed N.
meningitidis from
sterile site
Culture confirmed
N. meningitidis from
sterile site
MATS on
throat swab
PorA P1.4
genotyping
MATS on
sterile site
Case identification

35. Carriage studies - 1
Reduction in capsular group C carriage following
introduction of meningococcal serogroup C conjugate
vaccines
0
1
2
3
0
2
4
6
8
10
0
5
10
15
20
25
0
2
4
6
8
10
Meningococci
(% of isolates)
1999 2000 2001
Serogroup C
Serogroup YSerogroup B
Serogroup W
-71% -81%
Maiden MC et al. J Infect Dis. 2008;197:737-43.

36. Carriage studies - 2
•A phase III study (NCT01214850) enrolled 2968 students in 10 universities
across England from September-December 2010.
•Students received either one dose of a licensed quadrivalent meningococcal
conjugate vaccine, Menveo® (n = 956) followed by saline placebo, or two doses
of either meningococcal Bexsero® (n = 932) or Ixiaro® (n = 948).
•Oropharyngeal samples were taken before vaccination and at 5 subsequent
visits over one year.
•Primary analysis at one month after the vaccination series did not reveal
significant impact of either vaccine however across the cumulative later
timepoints:
 Menveo was associated with a carriage-reduction efficacy of 38.0% (95% CI:
15.9 – 54.2) against serogroup Y.
 Bexsero was associated with a decrease in carriage of genogroup
MenBCWY strains (24.2% [95% CI: 7.8 – 37.6].
Read R et al. ESPID 2013

37. Seroprevalence studies - 1
Ishola D, Borrow R, Findlow H, et al. Clin Vaccine Immunol 2012; 19:1126-30.
0
10
20
30
40
50
60
70
80
90
100
<6mths
6-11mths
1-4yrs
5-9yrs
10-14yrs
15-19yrs
20-24yrs
25-34yrs
35-44yrs
45-54yrs
55-64yrs
65+yrs
%withSBAtitre>=8
1996-99 2000-2004 2009
Proportions of sera with MenC SBA titres ≥8 by age in
England & Wales, pre and post-introduction of MCC
vaccines

38. Seroprevalence studies - 2
0
10
20
30
40
50
60
70
80
<0.3
0.3-0.59
0.6-0.99
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
1920-2425-3435-4445-5455-64
65+
age (years)
incidenceper100,000peryear
0%
10%
20%
30%
40%
50%
60%
%withSBAtitres>=4
incidence group B per 100,000 per year
SBA>=4
Age-specific incidence of group B disease compared to the
percentage of individuals with SBA ≥4 against strain
NZ98/254 (B:4:P1.7-2,4)
Trotter C, Findlow J, Balmer P, Holland A, Barchha R, Hamer N, Andrews N, Miller E, Borrow R. Clin Vaccine
Immunol 2007; May 9; 14:863-8.
• For Bexsero use strains 44/76-SL (fHbp); 5/99 (NadA); NZ98/254 (PorA).
• No useable strain for NHBA for seroprevalence studies though a UK NHBA
MATS +ve/fHbp & NadA MATS -ve with mismatched PorA is being investigated.

39. Conclusions
•Approximately 50% of cases cultured confirmed thus can fully characterise
utilising MATS.
•Non-culture confirmed cases:
- Nasopharyngeal isolates
- Non-culture PorA, P1.4
- non-culture fHbp but no information on expression
•Need means of quantifying expression levels direct from non-culture PCR
positive samples.
•Both nasopharyngeal carriage and seroprevalence need to be monitored.