PMID- 33857245
OWN - NLM
STAT- MEDLINE
DCOM- 20210924
LR  - 20210924
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 16
IP  - 4
DP  - 2021
TI  - Seroprevalence of meningococcal serogroup C bactericidal antibodies in the 
      Portuguese population, a decade after vaccine introduction in the National 
      Immunisation Programme.
PG  - e0250103
LID - 10.1371/journal.pone.0250103 [doi]
LID - e0250103
AB  - BACKGROUND: The incidence of invasive meningococcal disease due to serogroup C 
      (MenC) decreased in Portugal since the introduction of the conjugate vaccine 
      (MCC) in the free market in 2001 and in the National Immunisation Plan in 2006. 
      Considering the potential waning of the antibody response reported in the 
      literature, the different vaccination schemes that were used in our country over 
      the past decade, and that Neisseria meningitidis serogroup C continues to 
      circulate, the Portuguese population may currently be at increased risk of 
      infection. In the absence of national data, we evaluated the seroprotection level 
      of the Portuguese population against MenC, in order to identify the protected 
      fraction of the population and ponder on the necessity of a booster dose of the 
      MCC vaccine. METHODS: We measured serum bactericidal antibody levels against MenC 
      in a representative sample of the population (n = 1500) aged 2-64 years who 
      participated in the 2015/2016 National Serological Survey. RESULTS: A total of 
      31.1% (466/1500, 95%CI: 29-33%) of the individuals studied were protected against 
      MenC. The geometric mean titre was 6.5. The proportion of seroprotected was 
      particularly low in children aged 2-4 years (<16%) who received a single dose of 
      the vaccine at 12 months of age (vaccination strategy since 2012). The proportion 
      of seroprotected was higher (44.7% to 53.5%) in adolescent and young adults 
      (15-24 years of age), resulting from vaccination during the catch-up campaign at 
      5-15 years of age. The highest protection rates were observed when the vaccine 
      was administered during adolescence. CONCLUSION: The small fraction of population 
      seroprotected, combined with the already known waning effect of the antibody 
      response over time, may indicate that the Portuguese population will become 
      progressively more exposed to the risk of infection. Taking in consideration our 
      results, we recommend to change the current vaccination strategy and introduce a 
      booster dose of the MCC vaccine during adolescence.
FAU - Goncalves, Paulo
AU  - Goncalves P
AUID- ORCID: 0000-0002-4633-6306
AD  - National Institute of Health Doutor Ricardo Jorge, Lisboa, Portugal.
AD  - European Programme for Public Health Microbiology Training (EUPHEM), European 
      Centre for Disease Prevention and Control, Stockholm, Sweden.
FAU - Saez-Lopez, Emma
AU  - Saez-Lopez E
AD  - European Programme for Public Health Microbiology Training (EUPHEM), European 
      Centre for Disease Prevention and Control, Stockholm, Sweden.
FAU - Carneiro, Sofia
AU  - Carneiro S
AD  - National Institute of Health Doutor Ricardo Jorge, Lisboa, Portugal.
FAU - Simoes, Maria Joao
AU  - Simoes MJ
AD  - National Institute of Health Doutor Ricardo Jorge, Lisboa, Portugal.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20210415
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 0 (Meningococcal Vaccines)
SB  - IM
MH  - Adolescent
MH  - Child
MH  - Child, Preschool
MH  - Cross-Sectional Studies
MH  - Female
MH  - Humans
MH  - *Immunization Programs
MH  - Male
MH  - Meningococcal Infections/*epidemiology/immunology/prevention & control
MH  - Meningococcal Vaccines/*immunology
MH  - Neisseria meningitidis, Serogroup C/*immunology
MH  - Portugal
MH  - Retrospective Studies
MH  - Seroepidemiologic Studies
MH  - Young Adult
PMC - PMC8049472
COIS- The authors have declared that no competing interests exist.
EDAT- 2021/04/16 06:00
MHDA- 2021/09/25 06:00
PMCR- 2021/04/15
CRDT- 2021/04/15 17:27
PHST- 2020/10/29 00:00 [received]
PHST- 2021/03/30 00:00 [accepted]
PHST- 2021/04/15 17:27 [entrez]
PHST- 2021/04/16 06:00 [pubmed]
PHST- 2021/09/25 06:00 [medline]
PHST- 2021/04/15 00:00 [pmc-release]
AID - PONE-D-20-34068 [pii]
AID - 10.1371/journal.pone.0250103 [doi]
PST - epublish
SO  - PLoS One. 2021 Apr 15;16(4):e0250103. doi: 10.1371/journal.pone.0250103. 
      eCollection 2021.