DTaP-IPV/Hib vaccine (Pentacel)

The combination vaccine diphtheria and tetanus toxoids and acellular pertussis adsorbed, inactivated poliovirus and Haemophilus b conjugate (tetanus toxoid conjugate) vaccine (DTaP-IPV/Hib), which has been exclusively used in Canada for more than 10 years, is the first DTaP-based vaccine approved in the US that includes both poliovirus and Haemophilus influenzae type b (Hib) antigens. In clinical trials, the combined DTaP-IPV/Hib vaccine induced high immunogenecity against all of the vaccine antigens, including Hib. Administration of the DTaP-IPV/Hib vaccine as a four-dose series in infants provided high levels of seroprotection against diphtheria and tetanus toxoids, poliovirus types 1, 2, and 3, and Hib polyribosyl-ribitol-phosphate capsular polysaccharide conjugated to tetanus toxoid (PRP-T). Immune responses produced after doses 3 and 4 of DTaP-IPV/Hib vaccine were noninferior to those seen with separately administered DTaP, inactivated poliovirus, and Hib vaccines, apart from those against PRP-T in one study. Seroconversion rates for the five pertussis components in DTaP-IPV/Hib vaccine were noninferior to those seen in infants receiving the separately administered vaccines. A serology bridging study showed the noninferiority of four doses of DTaP-IPV/Hib vaccine to three doses of a DTaP vaccine in terms of seroconversion rates for filamentous hemagglutinin and fimbriae 2 and 3, but not pertactin. There were no clinically relevant changes in the immunogenicity of DTaP-IPV/Hib when coadministered with pneumococcal-7-valent-CRM197 vaccine or measles, mumps, and rubella vaccine and varicella zoster vaccine at 15 months. The tolerability profile of DTaP-IPV/Hib vaccine was generally similar to that of separately administered DTaP, IPV, and Hib vaccines.     

Haemophilus influenzae type b (Hib) vaccine: an effective control strategy in India

Haemophilus influenzae type b (Hib) is an encapsulated, non-motile and non-spore-forming Gram-negative coccobacillus which causes severe pneumonia, meningitis and other life threatening illnesses. Hib disease affects almost exclusively (95%) children aged less than 5 years throughout the world. The mean age of onset is 6-24 months after which it declines gradually until age 5 years. The World Health Organization (WHO) estimates that Hib is responsible for 3 million cases of serious illnesses and approximately 386,000 deaths worldwide each year in children aged under 5 years. In the latest position paper on Hib vaccine, WHO recommended the inclusion of Hib conjugate vaccines in all routine infant immunization programs without waiting for local disease-burden data. The WHO and the Global Alliance for Vaccine Immunization (GAVI) have been working to expand supplies of Hib vaccine, reduce vaccine cost, and assist especially low-income countries with vaccine introduction. Hib vaccine is safe, highly effective and readily available in the market. Hib vaccine has been shown to be > 95% efficacious in diverse populations around the world. Globally, hundreds of millions of doses of Hib vaccine have been administered in the last 2 decades. More than 160 countries are using Hib vaccine in national immunization programmes and around 25 countries planning to introduce. Hib vaccination fits into the India's national immunization schedule.     

Immunologic response to Hib tetanus toxoid conjugated vaccine coadministered with DTPa either mixed or in two separate injections in toddlers not primed with Hib vaccine

This open randomized study compared the immunogenicity and safety of a diphtheria-tetanus-acellular pertussis (DTPa) and H. influenzae polyribosylribitol phosphate conjugated to the tetanus toxoid (Hib-PRP-T) vaccine (mixed prior to administration) with separate injections of DTPa and Hib vaccines in toddlers aged two years. A total of 119 children (60 mixed; 59 separate administration), primed with DTPw, but not with Hib vaccine were enrolled. Prior to immunization only 10.3% of toddlers had anti-PRP antibody titres > or =1.0 microg/ml, compared with all children on Days 7 and 30. The anti-PRP and anti-tetanus antibody geometric mean concentrations were lower after the combined DTPa/Hib vaccine compared to separately administered vaccines (47.16 microg/ml vs 78.36 microg/ml and 24.95 IU/ml vs 40.63 IU/ml, respectively). One month after vaccination all children had anti-tetanus and anti-diphtheria antibody titres above the protective level of > or =0.1 IU/ml. The rates of recorded adverse events were similar and mostly mild or moderate in intensity whether the vaccines were combined as a single injection or given separately. We conclude that in 2-year old children, previously not immunized against Hib, a single dose of DTPa and Hib was safe and highly immunogenic irrespective of whether it was given as a combined vaccine or separate injections. Although the increase in anti-T and early (7-10 days after) anti-PRP concentrations was greater when the vaccine components were given separately than after combined administration, the DTPa/Hib combined vaccine would provide an effective method of delivering primary Hib vaccination in unprimed toddlers.     

Zoster vaccine live (Oka/Merck)

A subcutaneously administered, live, high-titre (18,700-60,000 plaque-forming units per dose) varicella zoster virus (VZV) vaccine (zoster vaccine) of the Oka/Merck strain has been evaluated for the prevention of herpes zoster and the reduction of zoster-associated pain in adults aged > or =60 years. Zoster vaccine, when compared with placebo, reduced the burden of herpes zoster illness by 61%, the incidence of herpes zoster by 51% and the incidence of postherpetic neuralgia by 67% during more than 3 years of surveillance. The zoster vaccine caused an initial 1.7-fold rise in VZV antibody titre after 6 weeks that declined progressively over 3 years. Increases in gamma-interferon-secreting peripheral blood mononuclear cells were 2.2-fold greater with the zoster vaccine than with placebo 6 weeks after vaccination. Zoster vaccine was generally well tolerated. The most frequently reported adverse reactions following vaccination were injection-site reactions; the only systemic adverse event with zoster vaccine that differed significantly in incidence from that with placebo was headache.     

A new DTPw-HBV/Hib vaccine is immunogenic and safe when administered according to the EPI (Expanded Programme for Immunization) schedule and following hepatitis B vaccination at birth

New combination vaccines and reliable sources of vaccine components are essential to ensure the success of mass immunisation programmes in the 21st century. We evaluated a new combined diphtheria-tetanus-whole-cell-pertussis-hepatitis B vaccine, extemporaneously mixed with a Haemophilus influenzae type b conjugate vaccine (DTPw-HBV/Hib) containing 2.5 microg PRP in 913 Philippino infants, administered according to the EPI schedule at 6, 10 and 14 weeks of age after a birth dose of hepatitis B vaccine (HBV; trial DTPw-HBV/Hib-001). One month after the third dose of DTPw-HBV/Hib (N = 182), 99.4% and 94.2% of subjects had anti-PRP antibody levels > or =0.15 microg/mL and > or =1.0 microg/mL, respectively. In addition, 95.9%, 100.0% and 87.6% of subjects had seroprotective antibody concentrations against diphtheria, tetanus and hepatitis B, respectively. The seroprotection rate to hepatitis B increased significantly to 94.3% in subjects who received a dose of HBV at birth. The pertussis vaccine response rate was > or =95%. Seroprotection/vaccine response rates to all antigens after DTPw-HBV/Hib were at least as good as those observed after vaccination with GSK Biologicals' licensed Tritanrix HepB/Hiberix (containing 10 microg PRP) which was used as comparator. Although redness >20 mm in diameter and fever > or = 37.5 degrees C (axillary route) occurred more often after the new DTPw-HBV/Hib vaccine (p < 0.05), other Grade 3 adverse events occurred similarly between the groups. The new DTPw-HBV/Hib vaccine was as immunogenic and well tolerated as the licensed control vaccine when administered according to the immunologically challenging EPI schedule. A birth dose of HBV is important to maximize protection against hepatitis B in endemic regions where the EPI schedule is in place.     

Meningitis C vaccine (North American vaccine)

North American Vaccine Inc (NAVI) has launched a conjugate polysaccharide vaccinefor the prevention of meningitis caused by group C meningococcal bacteria [433475]. The vaccine is based upon conjugate technology, incorporating the serogroup C polysaccharide (CPS) of all three major serogroups. Antibody-dependent, complement-mediated activity was demonstrated in mice and non-human primates, with no detectable adverse effects [277193]. Approval was filed for in the UK in January 2000 [353305]. In July 2000, Baxter received approval for NeisVac-C in the UK, and by September 2000 the vaccine was expected to be incorporated into the NHS's immunization campaign against meningitis C [381225]. NeisVac-C will initially appear labeled from NAVI; Baxter completed its acquisition of NAVI in June 2000 [375389]. Baxter estimates the worldwide global market for the vaccine at US $600 million per year [376204].     

A new DTPw-HBV/Hib vaccine: immune memory after primary vaccination and booster dosing in the second year of life

The response to booster vaccination at 15-18 months of age and the presence of immune memory in 10-month old children, primed with a new combined diphtheria-tetanus-hepatitis B-whole cell pertussis vaccine extemporaneously mixed with Haemophilus influenzae type b-tetanus toxoid conjugate (DTPw-HBV/Hib) from new antigen sources and containing 2.5 microg polyribosyl-ribitol-phosphate (PRP) was assessed. Primary vaccination with the new DTPw-HBV/Hib vaccine was immunogenic and of comparable tolerability to commercially available Tritanrix HepB/Hiberix. Children were boosted with DTPw-HBV, DTPw-HBV/Hib or separate DTPw-HBV+Hiberix. Immune memory was assessed through administration of 10 microg PRP polysaccharide. Anti-PRP antibody GMCs increased substantially after the challenge in DTPw-HBV/Hib-primed subjects indicating the presence of immune memory. One month after the booster dose, 100% of subjects had seroprotective antibody concentrations against PRP, diphtheria and tetanus, >95% were seroprotected against hepatitis B, > or =94.0% had a pertussis booster response. Substantial increases in antibody GMCs against all antigens were observed. Swelling >20 mm was the most common Grade 3 solicited symptom reported (up to 26.0% of subjects). Fever >39.5 degrees C was uncommon (>2.5%). Eleven large swelling reactions were reported; none involved an adjacent joint. One serious adverse event occurred that was considered unrelated to vaccination. This new DTPw-HBV/Hib vaccine with new vaccine components and 2.5 microg PRP induced effective priming against Hib evidenced by a vigorous anamnestic response on exposure to PRP polysaccharide. The booster dose was immunogenic and the safety profile was acceptable. Combined DTPw-HBV and DTPw-HBV/Hib vaccines using new vaccine antigen sources will promote continued supply of combined DTPw-based vaccines to global mass vaccination campaigns.     

Rotavirus vaccine (RotaTeq)

RotaTeq is a live, oral, pentavalent human-bovine reassortant rotavirus vaccine approved for use in the prevention of G1-G4 rotavirus gastroenteritis in infants and children. Rotavirus vaccine demonstrated good immunogenicity in healthy infants. Three oral doses of rotavirus vaccine had a protective efficacy against G1-G4 rotavirus gastroenteritis of any severity of 74%, and a protective efficacy against severe G1-G4 rotavirus gastroenteritis of 98%, in the randomized, double-blind, placebo-controlled, multicenter REST (Rotavirus Efficacy and Safety Trial) study; the per-protocol efficacy analysis included >4500 infants. Healthcare resource use was reduced by rotavirus vaccine, with a 94.5% reduction in the incidence of hospitalization or emergency department care because of G1-G4 rotavirus gastroenteritis. This analysis of the REST trial included >57,000 infants. Rotavirus vaccine did not increase the risk of intussusception within 42 days of any dose, according to an analysis of the REST trial including almost 70,000 infants. Rotavirus vaccine and placebo were associated with serious adverse events in <3% of infants in either group.     

Rotavirus vaccine RIX4414 (Rotarix)

RIX4414 is a human, live attenuated rotavirus vaccine containing a rotavirus strain of G1P[8] specificity; it is administered orally using a two-dose schedule. RIX4414 showed good immunogenicity in healthy infants in several well designed trials in terms of both seroconversion rates and vaccine take. Moreover, RIX4414 did not impair the immune response of infants to other vaccines. RIX4414 provided significant protection against severe rotavirus gastroenteritis. In a subgroup analysis (n = 20 169) of a large (n = 63 225), well designed, placebo-controlled, phase III trial (conducted in Latin America and Finland), the efficacy of RIX4414 against severe rotavirus gastroenteritis was 85% in healthy infants, with an efficacy against hospitalization for severe rotavirus gastroenteritis of 85%. RIX4414 provided cross-protection against non-G1 serotypes containing the P[8] antigen. Moreover, in this trial, RIX4414 had a protective efficacy against severe gastroenteritis of any cause of 40%, with an efficacy against hospitalization because of severe gastroenteritis of any cause of 42%. In another well designed, placebo-controlled, phase III trial (conducted in Europe; n = 3874), RIX4414 had an efficacy against rotavirus gastroenteritis of any severity of 87%, an efficacy against severe rotavirus gastroenteritis of 96%, and an efficacy against hospitalization because of rotavirus gastroenteritis of 100%. RIX4414 protected against rotavirus gastroenteritis from the first dose onwards. A meta-analysis revealed that RIX4414 had a protective efficacy against rotavirus gastroenteritis of any severity caused by the G2P[4] serotype of 81% and against severe rotavirus gastroenteritis caused by the G2P[4] serotype of 71%. RIX4414 was generally well tolerated in healthy infants. The vaccine did not appear to be associated with an increased risk of intussusception.     

Crossover vaccination with quadrivalent meningococcal vaccine (against A/C/Y/W-135) following recent application of bivalent meningococcal vaccine (against A/C): assessment of safety and side effect profile

BACKGROUND: Until May 2000, bivalent A/C meningococcal vaccine was the only available vaccine in Singapore for hajj travelers to Saudi Arabia. Recent worldwide reports of serogroup W-135 meningococcal meningitis associated with hajj returnees necessitated switching to quadrivalent A/C/Y/W-135 vaccine and crossover vaccination of travelers to Saudi Arabia. No safety data are available for quadrivalent vaccine following recent vaccination with bivalent vaccine. We assessed the safety and side effect profile of bivalent, quadrivalent, and quadrivalent meningococcal vaccine after recent vaccination with bivalent vaccine. METHODS: A postvaccination telephone questionnaire survey was performed for all travelers who received either bivalent (B), quadrivalent (Q), or quadrivalent with recent (as defined by less than 6 months before) bivalent meningococcal vaccine (BQ) between 22 May and 8 June 2000 in preparation for the umrah (minor pilgrimage). Patients were asked about local reactions (pain, erythema, swelling at injection site graded in mild, moderate, and severe) and systemic reactions (fever, headache, graded in mild and severe). RESULTS: Of 546 persons vaccinated, 323 were interviewed. Median time interval between interview and vaccination was 10 days. Of those interviewed, 64 patients received bivalent (B), 213 quadrivalent (Q), and 46 quadrivalent after recent bivalent vaccine (BQ). The median interval time between previous bivalent and quadrivalent vaccine was 5 weeks. There was no statistically significant difference in the prevalence of side effects between the three groups. Mild pain at injection site was recorded in B as 21.8%, Q as 23%, BQ as 21.7%; low grade fever in B as 7.8%, Q as 9.8%, and BQ as 15.2%. CONCLUSIONS: Bivalent and quadrivalent meningococcal vaccine are well tolerated. Crossover vaccination of quadrivalent meningococcal vaccine after recent vaccination with bivalent vaccine does not increase the prevalence of adverse reactions and is therefore safe.     

重组人乳头瘤病毒双价(16/18型)疫苗免疫原性评价方法的研究

目的:探讨重组人乳头瘤病毒双价(16/18型)候选疫苗免疫原性评价方法。方法:对以假病毒为基础的中和实验(Zs-Green法)测定血清中和滴度,以微球为基础建立的Luminex法测定中和滴度和ELISA法测定抗体滴度的3种方法进行相关性研究以及体内效价测定(ED50法)和体外相对效力测定(IVRP法)的相关性分析,同时对5种免疫原性的评价方法进行重复性验证。结果:ZsGreen法、Luminex法测定的中和滴度和ELISA法测定的抗体滴度检测结果表明:滴度值呈明显的剂量效应以及侯选疫苗具有良好的免疫原性。采用SPSS统计软件分析,对于HPV 16L1 ZsGreen法、Luminex法和ELISA法的相关系数分别为0.791,0.800,0.747(Spearman相关系数)和HPV 18L1的相关系数分别为0.734,0.625,0.634(Spearman相关系数)。并且ED50法和IVRP法具有一定的相关性。5种方法重复性验证的RSD分别为:5.3%(ZsGreen)、5.2%(Luminex)、8.0%(ELISA)、32.3%(ED50)、6.3%(IVRP)。结论:建立的HPV 16和HPV 18...