Hepatitis B vaccination: long-term follow-up of the immune response of preterm infants and comparison of two vaccination protocols

Background: We conducted a 3-year follow-up study of long-term antibody persistence following vaccination of low-risk preterm infants with recombinant hepatitis B vaccine (HBV). Two three-dose protocols were compared: vaccination beginning within 24 h of birth to initial vaccination delayed until a weight of 2,000 g was reached. Patients and Methods: The study population included 136 children, divided into three groups: children born prematurely (≤ 35 weeks, n = 57), children born at term (≥ 37 weeks, n = 39), both groups receiving the first dose of HBV within 24 h of birth, and children born prematurely (≤ 35 weeks, n = 40), who received the first dose of HBV when a weight of 2,000 g was reached. All infants received the second hepatitis vaccination 1 month after the first, and the third dose 6 months after the first. Hepatitis B surface antibody (AntiHBs) was measured at an age of 3–3.5 years (at least 2.5 years after completion of the three-dose HBV series). An AntiHBs level of ≥ 10 IU/l was considered positive. Results: At 3–3.5 years of age, a higher percentage of the premature-delayed vaccination group had a positive AntiHBs level (92.5%) compared to both the premature (54.5%, p < 0.001) and full-term groups (71.8%, p < 0.05) vaccinated soon after birth. The premature-delayed vaccination group also had a significantly higher geometric mean concentration (GMC) (119 vs 14.2 IU/l, p < 0.001 and 119 vs 32.7 IU/l, p < 0.005, respectively). Conclusion: Delaying vaccination of premature infants against hepatitis B until a weight of 2,000 g was reached resulted in both a significantly higher percentage of children with positive antibody levels and a significantly higher GMC at 3–3.5 years of age as compared to early-vaccinated preterm and full-term infants. The known short-term advantage of delayed vaccination of preterm infants was shown to persist for at least the first 3 years of life. Received: July 12, 2001 · Revision accepted: January 8, 2002     

Vaccines for Health Care Personnel

Medical Center Occupational Health (MCOH) programs must protect health care personnel (HCP) against the occupational risk of vaccine-preventable diseases. This thematic review outlines the rationale for the use of recommended vaccines in HCP; summarizes the available evidence regarding vaccine effectiveness, administration, and assessment of immunity; and provides guidance for MCOH programs navigating challenging situations.     

Maternal immunization: where are we now and how to move forward?

Pregnancy and the postpartum period are associated with elevated risks to both mother and infant from infectious disease. Vaccination of pregnant women, also called maternal immunization, has the potential to protect pregnant women, foetuses and infants from several vaccine-preventable diseases. Maternal immunoglobulin G antibodies are actively transferred through the placenta to provide passive immunity to new-borns during the first months of life, until the time for infant vaccinations or until the period of greatest susceptibility has passed. Currently, inactivated influenza, tetanus, and pertussis vaccines are recommended during pregnancy in many countries, but other vaccines may also be administered to pregnant women when risk factors are present. Several new vaccines with a specific indication for use during pregnancy are under development (e.g. respiratory syncytial virus and group B streptococcus vaccines). Years of experience suggest that maternal immunization against influenza, tetanus or pertussis has an acceptable safety profile, is well tolerated, effective and confers significant benefits to pregnant women and their infants. This review describes the principles of maternal immunization and provides an update of the recent evidence regarding the use and timing of maternal immunization. Finally, the barriers preventing wider vaccination coverage and the current limitations in addressing these are also described (Supplementary Material).

• Key messages

• Maternal immunization gives pregnant women greater protection against infectious diseases; induces high levels of maternal antibodies that can be transferred to the foetus; and helps protect new-borns during their first months of life, until they are old enough to be vaccinated.

• Pregnant women and new-borns are more vulnerable to infectious diseases than the overall population; nevertheless, vaccination rates are often low in pregnant women.

• This review provides an update of the recent evidence regarding the use and timing of maternal immunization and describes the barriers preventing wider vaccination uptake and the current limitations in addressing these.

     

Serogroup W Meningitis Outbreak at the Subdistrict Level,Burkina Faso, 2012

In 2012, Neisseria meningitidis serogroup W caused a widespread meningitis epidemic in Burkina Faso. We describe the dynamic of the epidemic at the subdistrict level. Disease detection at this scale allows for a timelier response, which is critical in the new epidemiologic landscape created in Africa by the N. meningitidis A conjugate vaccine.     

Redesigned immunization card and center-based education to reduce childhood immunization dropouts in urban Pakistan: a randomized controlled trial

In Pakistan during 2000-2004, about 11-13% of children who received the first dose of diphtheria-pertussis-tetanus (DPT1) failed to complete its third dose (DPT3). We assessed the effect of a redesigned immunization card and center-based education to mothers on DPT3 completion. We enrolled 1500 mother-child units at DPT1, randomized them to three intervention and one standard care groups, and recorded their DPT3 visits during a 90-day follow-up. In multivariable analysis, a significant increase of 31% (adjusted RR=1.31, 95% CI=1.18-1.46) in DPT3 completion was estimated in the group that received both redesigned card and center-based education compared with the standard care group.     

Delivery to the lower respiratory tract is required for effective immunization with Newcastle disease virus-vectored vaccines intended for humans

Newcastle disease virus (NDV), an avian virus, is being evaluated for the development of vectored human vaccines against emerging pathogens. Previous studies of NDV-vectored vaccines in a mouse model suggested their potency after delivery by injection or by the intranasal route. We compared the efficacy of various routes of delivery of NDV-vectored vaccines in a non-human primate model. While delivery of an NDV-vectored vaccine by the combined intranasal/intratracheal route elicited protective immune responses, delivery by the subcutaneous route or the intranasal route alone elicited limited or no protective immune responses, suggesting the necessity for vaccine delivery to the lower respiratory tract. Furthermore, direct comparison of a vaccine based on an NDV mesogenic strain (NDV-BC) with a similarly designed NDV vector based on a modified lentogenic strain carrying a polybasic F cleavage site (NDV-VF) suggested that the two NDV strains were similar in immunogenicity and were equally protective.     

Integration of insecticide-treated net distribution into routine immunization services in Malawi: a pilot study

Objectives  To determine the feasibility of distributing insecticide-treated nets (ITNs) through routine immunization services, to increase ownership and use of ITNs among high-risk groups, whereas maintaining or improving timely completion of routine vaccinations.
Methods  Free ITNs were provided with timely completion of routine vaccinations in two intervention districts in southern Malawi for 15 months. Cross-sectional baseline and follow-up household surveys were conducted in the two intervention districts and one control district.
Results  Insecticide-treated nets utilization among children aged 12–23 months roughly doubled in the two intervention districts and did not change in the control district. Timely vaccination coverage increased in all three districts. The percentage of children aged 12–23 months who were both fully vaccinated by 12 months and slept under an ITN the night prior to the interview increased from 10–14% at baseline to 40–44% at follow-up in the intervention districts ( P  < 0.001), but did not change significantly in the control district.
Conclusions  This study is the first to evaluate the provision of free ITNs at completion of a child's primary vaccination series, demonstrating that such a linkage is both feasible and can result in improved coverage with the combined services. Additional studies are needed to determine whether such a model is effective in other countries, and whether integration of other health services with immunization delivery could also be synergistic.     

Prevention of the murine model of biliary atresia after live rotavirus vaccination of dams

Purpose

Biliary atresia (BA) is a neonatal disease that results in the obliteration of the biliary tree. The murine model of BA has been established where rhesus rotavirus (RRV) infection of newborn mice leads to an obstructive cholangiopathy. We determined whether maternal postconception rotavirus vaccination could prevent the murine model of BA.

Materials and Methods

Female mice were mated and injected intraperitoneally with one of the following materials: purified rotavirus strains RRV or Wa, high or low-dose Rotateq (Merck and Co Inc, Whitehouse Station, NJ) (a pentavalent rotavirus vaccine [PRV]), purified recombinant viral antigens of rotavirus (VP6) or influenza (NP), or saline. B-cell-deficient females also underwent postconception PRV injection.

Results

Maternal vaccination with PRV improves survival of pups infected with RRV. Serum rotavirus IgG, but not IgA, levels were increased in pups delivered from dams who received RRV, Wa, PRV, or VP6, but in the case of the Wa, PRV, and VP6 groups, these antibodies were not neutralizing. Postconception injection of high-dose PRV did not improve survival of pups born to B-cell-deficient dams.

Conclusion

Maternal vaccination against RRV can prevent the rotavirus-induced murine model of BA in newborn mouse pups.     

Brain tumor therapy by combined vaccination and antisense oligonucleotide delivery with nanoparticles

We examined a “double-punch” approach to overcome the escape of glioblastoma cells to the immune surveillance: increasing the immune systems activation by an active specific immunization (ASI) with Newcastle-Disease-Virus infected tumor cells and blocking the TGF-β production by delivery of TGF-β antisense oligonucleotides using polybutyl cyanoacrylate nanoparticles (NPs). Gene delivery was first evaluated using the CMV-β-gal plasmid as a reporter gene. Fischer rats received implantation of glioblastoma cells into the brain and were then treated with combined ASI/NP-anti-TGF-β formulation. Massive staining of tumor cells was seen after NP delivery of the plasmid β-galactosidase, indicating gene transfer by nanoparticles to tumor cells. When treated with NP-anti-TGF-β after having been immunized, the rats survived longer than untreated controls, had reduced TGF-β-levels and showed increased rates of activated CD25+ T cells. In summary, nanoparticles are useful to deliver plasmids and antisense oligonucleotides to brain tumors. A combined immunization/gene delivery of TGF-β antisense oligonucleotides may be a promising approach for brain tumor therapy.