Swart E M, van Gageldonk P G M, de Melker H E, van der Klis F R, Berbers G A M, Mollema L
Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands.
PLoS One. 2016 Feb 10;11(2):e0148605. doi: 10.1371/journal.pone.0148605. eCollection 2016.
To evaluate the National Immunisation Programme (NIP) a population-based cross-sectional seroepidemiological study was performed in the Netherlands. We assessed diphtheria antitoxin levels in the general Dutch population and in low vaccination coverage (LVC) areas where a relatively high proportion of orthodox Protestants live who decline vaccination based on religious grounds. Results were compared with a nationwide seroepidemiological study performed 11 years earlier.
In 2006/2007 a national serum bank was established. Blood samples were tested for diphtheria antitoxin IgG concentrations using a multiplex immunoassay for 6383 participants from the national sample (NS) and 1518 participants from LVC municipalities. A cut-off above 0.01 international units per ml (IU/ml) was used as minimum protective level.
In the NS 91% of the population had antibody levels above 0.01 IU/ml compared to 88% in the 1995/1996 serosurvey (p<0.05). On average, 82% (vs. 78% in the 1995/1996 serosurvey, p<0.05) of individuals from the NS born before introduction of diphtheria vaccination in the NIP and 46% (vs. 37% in the 1995/1996 serosurvey, p = 0.11) of orthodox Protestants living in LVC areas had antibody levels above 0.01 IU/ml. Linear regression analysis among fully immunized individuals (six vaccinations) without evidence of revaccination indicated a continuous decline in antibodies in both serosurveys, but geometric mean antibodies remained well above 0.01 IU/ml in all age groups.
The NIP provides long-term protection against diphtheria, although antibody levels decline after vaccination. As a result of natural waning immunity, a substantial proportion of individuals born before introduction of diphtheria vaccination in the NIP lack adequate levels of diphtheria antibodies. Susceptibility due to lack of vaccination is highest among strictly orthodox Protestants. The potential risk of spread of diphtheria within the geographically clustered orthodox Protestant community after introduction in the Netherlands has not disappeared, despite national long-term high vaccination coverage.
为评估国家免疫规划（NIP），在荷兰开展了一项基于人群的横断面血清流行病学研究。我们评估了荷兰普通人群以及低疫苗接种覆盖率（LVC）地区的白喉抗毒素水平，在这些地区居住着相对较高比例基于宗教原因拒绝接种疫苗的东正教新教徒。将结果与11年前进行的一项全国血清流行病学研究进行了比较。
2006/2007年建立了一个国家血清库。使用多重免疫测定法检测了来自全国样本（NS）的6383名参与者和来自LVC市的1518名参与者的血样中的白喉抗毒素IgG浓度。每毫升高于0.01国际单位（IU/ml）的临界值被用作最低保护水平。
在全国样本中，91%的人群抗体水平高于0.01 IU/ml，而在1995/1996年血清学调查中这一比例为88%（p<0.05）。平均而言，在国家免疫规划中白喉疫苗接种引入之前出生的全国样本个体中，82%（1995/1996年血清学调查中为78%，p<0.05）以及居住在LVC地区的东正教新教徒中有46%（1995/1996年血清学调查中为37%，p = 0.11）的抗体水平高于0.01 IU/ml。在没有再次接种证据的完全免疫个体（接种六次）中进行的线性回归分析表明，在两次血清学调查中抗体水平均持续下降，但所有年龄组的几何平均抗体水平仍远高于0.01 IU/ml。
国家免疫规划提供了对白喉的长期保护，尽管接种疫苗后抗体水平会下降。由于自然免疫力减弱，在国家免疫规划中白喉疫苗接种引入之前出生的相当一部分个体缺乏足够水平的白喉抗体。在严格的东正教新教徒中，因未接种疫苗导致的易感性最高。尽管荷兰全国长期保持高疫苗接种覆盖率，但在荷兰引入白喉后，白喉在地理上聚集的东正教新教社区内传播的潜在风险并未消除。
