Tetanus-diphtheria vaccination in adults: the long-term persistence of antibodies is not dependent on polyclonal B-cell activation and the defective response to diphtheria toxoid re-vaccination is associated to HLADRB1∗01

Safety of Multiple Vaccinations and Durability of Vaccine-Induced Antibodies in an Italian Military Cohort 5 Years after Immunization

“…The analysis with the method of Hammarlund et al has been calculated in two ways, as described in materials and methods. The different methods provided similar results showing an increased estimation of durability for menPs antibodies compared with our previous study [ 5 ], and a reduced estimation for tetanus, diphtheria [ 6 ], and polio 1 and 3 [ 7 ]. However, the persistence of anti-menPsA antibodies in the subjects of group 2 and of anti-HAV in those immunized with the HAV vaccine could not be calculated, because the respective curves were slightly ascending.…”

“…We had already the opportunity to explore this possible mechanism of memory maintaining in 56 individuals of our military cohort, not recently boosted for tetanus/diphtheria toxoids but recently boosted with other not correlated vaccines and analyzed with anti-diphtheria antibodies only, as a read-out system, considering that anti-tetanus antibodies may be influenced by possible accesses to the emergency room. The results did not support the thesis, since in only 4/56 subjects (7%) the specific antibodies were doubled compared to T0 levels [ 6 ]. In the current study we wanted to deepen this topic, by comparing the response to measles, mumps, and rubella antigens in 10 subjects who had, and 10 subjects who had not, received vaccine boosters other than MMR between T2 and T3.…”

“…The current study, by adding a new distant point to the monitoring of post-vaccine antibody levels, has allowed to better calculate the durability of vaccine-induced antibodies. In fact, this has been analyzed not only with the method of Hammarlund et al [ 21 ], which has already been used in the published studies of this cohort [ 5 , 6 , 7 ] but it was also estimated (considering a linear decay) by the study of the slope of the line passing through the GMCs at T2 and T3 and the point of the intersection with the threshold line for protection. The analysis with the method of Hammarlund et al has been calculated in two ways, as described in materials and methods.…”

“…As previously reported [ 6 ], serum antibodies were examined by enzyme-linked immunosorbent assay (ELISA) commercial kits: NovaLisaTM Clostridium tetani toxin IgG-ELISA and Corynebacterium diphtheriae toxin 5S—IgG plus—ELISA (NovaTech Immunodiagnostica GmbH, Dietzenbach, Germany). Antibody concentrations 0.1 IU/mL were considered protective [ 15 ].…”

“…In the attempt to provide a further contribution in this field, we analyzed a military cohort composed of two different groups, group 1 was formed of military students at the military schools, thus newly enrolled and vaccinated, and stably operating in the national borders for at least 3 years, corresponding to the minimum length of the training period, and group 2 of older military individuals, periodically engaged in a 9-month operational activity abroad (Lebanon). Previous studies have allowed establishing that no autoimmune/lymphoproliferative phenomena could be observed up to 9-month post-vaccination in both groups [ 4 ]; moreover, the specific immune response to meningococcal tetravalent polysaccharide vaccine [ 5 ], tetanus/diphtheria [ 6 ] and viral vaccines, including hepatitis A virus (HAV), measles, mumps, and rubella (MMR), polio and influenza [ 7 ] was excellent and long durable.…”