Oral Poliomyelitis Vaccine Research Articles

Poliomyelitis eradication in China: 1953-2012.

Poliomyelitis has historically been endemic in China and has been considered an important cause of disability and death. We reviewed strategies and measures of poliomyelitis control and eradication from 1953 to 2012. Data from notifiable disease and routine immunization reporting systems and acute flaccid paralysis (AFP) surveillance were analyzed. About 20 000 poliomyelitis cases were reported annually in the prevaccine era. During 1965-1977, live, attenuated oral poliomyelitis vaccine (OPV) was administered to children through annual mass campaigns in the winter, and the number of poliomyelitis cases started to decline. A cold chain system was established during 1982, and OPV coverage increased during the early stage of the Expanded Programme on Immunization, from 1978 to 1988. Between 1989 and 1999, routine immunization was strengthened, supplementary immunization activities (SIAs) were conducted, and the AFP surveillance system was established. China reported a last indigenous poliomyelitis case in 1994 and was certified as free of polio in 2000. To maintain its polio-free status, China kept >90% coverage of 3 doses of OPV, conducted SIAs in high-risk areas, and maintained high-quality of AFP surveillance. China succeeded in stopping the outbreak in Xinjiang in 2011. China's polio-free status was achieved and maintained through strengthening routine immunization and implementing SIAs and AFP surveillance.

The challenge of changing the inactivated poliomyelitis vaccine in Latin America: declaration of the Latin American Society of Pediatric Infectious Diseases (SLIPE).

Even though we have already covered 99% of the path to eradicate poliomyelitis from the world, this disease is still causing paralysis in children. Its eradication means not only the end of wild poliovirus circulation, but vaccine-derived poliovirus circulation as well. Taking into account different factors such as: current epidemiological data, adverse events of the attenuated oral poliomyelitis vaccine (OPV), the availability of an injectable inactivated vaccine (IPV) without the potential of causing the severe adverse events of the oral vaccine (OPV), the efficacy and effectiveness of the IPV in several countries of the world where it has been used for several years, the rationale of changing the vaccination schedule in different Latin American countries; the Latin American Society of Pediatric Infectious Diseases (SLIPE) announces its recommendation of switching to IPV in Latin America, by this Declaration, with an Action Plan for 2014-2015 period as regards vaccination against polio policies in Latin America. 1. The optimal proposed schedule consists of four IPV doses (three doses in the primary schedule plus a booster dose), whether IPV is combined or not with other indicated vaccines in the immunization program of the country. During the OPV to IPV transition phase, an alternative schedule is acceptable; 2. Countries should set optimal strategies in order to maintain and improve vaccination coverage, and implement a nominal immunization registry; 3. Improving the Epidemiological Surveillance of Acute Flaccid Paralysis (AFP) and setting up an environmental surveillance program; 4. Setting up strategies for introducing IPV in National Immunization Programs, such as communicating properly with the population, among others; 5. Bringing scientific societies closer to decision makers; 6. Ensuring optimal supply and prices for IPV introduction; 7. Training vaccination teams; 8. Enhancing the distribution and storing logistics of vaccines. In addition to the scientific evidence, the countries that have not yet decided to switch to IPV should consider the implications of equity and social justice.

Predictors of optional immunization uptake in an urban south Indian population

BackgroundIn Tamil Nadu, India, bacille Calmette–Guérin, diphtheria–tetanus–pertussis, oral poliomyelitis, hepatitis B, and measles vaccines are part of the routine immunization schedule and are available free from government health centers. All other vaccines are optional and available in the private sector at a cost to families. This study assesses immunization rates of routine and optional vaccines and examines parental attitudes toward vaccines in Pallavapuram, Tamil Nadu. MethodsThe cluster sampling method was used to estimate immunization coverage. Seven children 18 to 36 months old were selected from 30 clusters for a total sample of 210 children. Demographics and vaccination data were collected from interviews and immunization records. Predictors of vaccination status were identified with logistic regression models. In addition, 21 parents participated in semi-structured interviews regarding their attitudes toward vaccination. Interviews were analyzed qualitatively for themes. ResultsEighty one percent of children were fully immunized with routine vaccines. However, only 21% received all “major” optional vaccines, defined as 3 doses of Haemophilus influenzae type b vaccine, one dose of measles, mumps, rubella vaccine, and one dose of varicella zoster virus vaccine. Birth in a private hospital (OR 5.6, 95% CI 1.3 to 22.9, P<0.01), higher income (P=0.03), and maternal completion of high school (OR 6.4, 95% CI 1.5 to 27.6, P<0.01) were significant predictors of receiving all major optional vaccines. Elucidated themes from interviews included (1) strong parental support for immunizations, (2) low concern for side effects, and (3) low uptake of optional vaccines due to high cost and lack of awareness. ConclusionsCoverage of optional vaccines is low despite positive attitudes toward immunizations. Efforts to reduce cost and increase awareness of these vaccines particularly among low-income families or to include these vaccines in the routine schedule may increase uptake and reduce morbidity and mortality from vaccine-preventable diseases.

Routine childhood vaccination programme coverage, El Salvador, 2011—In search of timeliness

While assessing immunization programmes, not only vaccination coverage is important, but also timely receipt of vaccines. We estimated both vaccination coverage and timeliness, as well as reasons for non-vaccination, and identified predictors of delayed or missed vaccination, for vaccines of the first two years of age, in El Salvador.We conducted a cluster survey among children aged 23–59 months. Caregivers were interviewed about the child immunization status and their attitudes towards immunization. Vaccination dates were obtained from children immunization cards at home or at health facilities. We referred to the 2006 vaccination schedule for children below two years: one dose of BCG (Bacillus Calmette-Guérin) at birth; rotavirus at two and four months; three doses of pentavalent – DTP (diphtheria-tetanus-pertussis), hepatitis B, and Haemophilus influenzae type b (Hib) – and of oral poliomyelitis vaccine (polio) at two, four, and six months; first MMR (measles-mumps-rubella) at 12 months; and first boosters of DTP and OPV at 18 months. Timeliness was assessed with Kaplan–Meier analysis; Cox and logistic regression were used to identify predictors of vaccination.We surveyed 2550 children. Coverage was highest for BCG (991%; 95% CI: 98.8–99.5) and lowest for rotavirus, especially second dose (86.3%; 95% CI: 84.2–88.4). The first doses of MMR and DTP had 991% (95% CI: 98.5–99.6) and 977% (95% CI: 970–985), respectively. Overall coverage was 837% (95% CI: 81.4–86.0); 96.4% (95% CI: 95.4–97.5), excluding rotavirus. However, only 26.7% (95% CI: 24.7–28.8) were vaccinated within the age interval recommended by the Expanded Programme on Immunization. Being employed and using the bus for transport to the health facility were associated with age-inappropriate vaccinations; while living in households with only two residents and in the “Paracentral”, “Occidental”, and “Oriental” regions was associated with age-appropriate vaccinations. Vaccination coverage was high in El Salvador, but general timeliness and rotavirus uptake could be improved.

Poliomyelitis eradication: Rhetoric or reality

Since the launch of Global Polio Eradication Initiative in 1988, disease burden has been reduced by more than 99% globally. Lately, India has witnessed a year without a case of poliomyelitis. It no longer stands endemic and is being regarded as a model for polio eradication efforts in other low income endemic countries: Pakistan, Nigeria and Afghanistan. The near elimination of wild polio virus in India has set forth new challenges of vaccine derived polio virus and need for newer strategies in oral poliomyelitis vaccine cessation preparatory phase. Stricter surveillance measures are needed to check for importations, any spread of virus in migratory populations and rapid containment of newly found virus. No stone should be left unturned in this last ditch effort for extermination of polio virus form environmental circulation. India's battle against polio will be cited as the biggest public health achievement or the most expensive public health failure.

Stability study of razi trivalent and monovalent oral poliomyelitis vaccine.

Stability studies play a critical role in assuring product quality at all points in the vaccine life cycle. These studies used to determine vaccine expiry date and vaccine efficacy. Accelerated stability and long term stability study performed for three batches of trivalent oral poliomyelitis vaccine (OPV) and three batches of monovalent OPV (type1) manufactured by Razi institute. After sampling, the samples tested intervals in months for long term stability and after 48h incubation in 37 0C for accelerated stability. All of quantitative and qualitative control tests including Potency, Sterility, Mycoplasma detection and Physicochemical testes performed in each period. Potency test for trivalent OPV (tOPV) in three batches of vaccines until 26 months and in two batches, until 27 months after production, met the specification. Potency test for monovalent OPV (mOPV) in all batches of vaccines until 18 month after production met the specification. Sterility, mycoplasma and physicochemical testes on these samples for mOPV and tOPV until expiry date and after that, passed. All batches of vaccines in accelerated stability met the specification after incubation and the reduction titer of vaccines was less than 0.5(-LogCCID50/dose). Results of this research indicated razi polio vaccines are stable for 24 months if the cold chain considered properly.

Haemophilus influenzae type b combination vaccines and atopic disorders: A prospective cohort study

Epidemiologic evidence for an association between vaccinations and atopy development is inconsistent. We evaluated the influence of Haemophilus influenzae type b (Hib) combination vaccines in 6-month-old infants on the prevalence of atopic disorders in 18-month-old children. We used multistage, stratified systematic sampling to recruit 24,200 mother-newborn pairs from the Taiwan national birth registration in 2005. Vaccination status was ascertained through official vaccine cards, while risk factors for atopic disorders were gathered by questionnaires at 6 months of age. Information about development of atopic dermatitis (AD) and recurrent wheezing was collected at 18 months of age. The relationship between atopic disorders and Hib combination vaccines, diphtheria-pertussis-tetanus-Hib and oral poliomyelitis vaccines (DPT-Hib&OPV) and DPT-Hib-inactivated poliomyelitis vaccines (DPT-Hib-IPV), were estimated by multiple logistic regression. A total of 19,968 children completed the follow-up and participated in the study. AD was noted in 1584 (7.9%) infants while recurrent wheezing was found in 1220 (6.1%) infants. The adjusted odds ratios (ORs) (95% CI) for the development of AD in the DPT-Hib&OPV and DPT-Hib-IPV vaccination groups were given as 1.38 (1.15-1.65) and 1.49 (1.29-1.72), compared to those without Hib vaccination (DTP&OPV vaccination). However, the association between DPT-Hib&OPV and DPT-Hib-IPV vaccinations and recurrent wheezing failed to reach statistical significance. There is a potential risk for AD after receiving Hib combination vaccines. Hib vaccination is important to the public health, and therefore the observation requires further investigations.

Birth of a Cold War Vaccine

The article presents a historical overview of the development of the oral trivalent poliomyelitis vaccine by virologist Albert B. Sabin in the 1950s. Particular focus is given to the successful research collaboration between Sabin and Russian virologist Mikhail P. Chumakov to test the efficacy of the live oral vaccine, despite rising Cold War tensions between the U.S. and the Soviet Union. Other topics discussed include Sabin's rivalry with injectable poliovirus vaccine inventor Jonas Salk, U.S. Federal Bureau of Investigations (FBI) scrutiny of Sabin's political views, and the acceptance of the Soviet clinical trial results by scientists in Western countries and the World Health Organization (WHO). INSET: IN BRIEF.

HEADS UP

HEADS UP

HEADS UP

The global campaign has resulted in a 99% decline in paralytic poliomyelitis since 1988, using, predominantly, trivalent oral polio vaccine (OPV). While poliovirus type 2 has been eradicated, endemic disease with type 1 and 3 polioviruses persists in some areas, notably in India and Nigeria. This is because of low vaccine coverage, although low efficacy of trivalent OPV may also be responsible. Two recent studies compared monovalent and trivalent OPV.1,2 In Nigeria,1 a case control study of 3624 persons with type 1 paralytic poliomyelitis estimated the field effectiveness of one dose of either monovalent type 1 vaccine or trivalent vaccine to be 67% and 16%, respectively. Trivalent OPV was only 18% effective against type 3 paralytic poliomyelitis, but too few doses of monovalent type 3 vaccine were given to assess its effectiveness.1 In Egypt,2 the immunogenicity of a birth dose of oral monovalent type 1 vaccine was superior to trivalent OPV; 55% and 32% seroconversion rates, respectively. In addition, fewer babies who received the monovalent vaccine shed type 1 virus after a challenge dose of oral monovalent vaccine at 30 days of age (26% vs. 42% with trivalent OPV). These two studies support the potential benefit of using monovalent oral poliomyelitis vaccines to eliminate disease transmission in remaining endemic areas. However, maintaining high vaccine coverage, with whatever vaccines are used, remains a challenge. Submitted by: Dr. Kristine Macartney (kristinm@chw.edu.au) This is an extremely important paper. The usual reasons for not continuing antibiotic treatment in newborns with sterile blood cultures was to prevent selection of resistant organisms and to prevent systemic fungal infection. This is a large 4-year, retrospective, multi-centre cohort study of extremely low-birthweight babies (<1000 g). Included babies (n= 4039) received antibiotics within 3 days of birth, had sterile blood cultures and survived for 5 days or more. Babies who received prolonged antibiotic therapy, defined as five or more days of antibiotics, despite negative blood cultures, were compared with babies whose antibiotics were stopped earlier. There was predictable selection bias: babies who received prolonged antibiotics were sicker, less mature, had lower Apgar scores, and were more likely to be black. However, after adjusting for these factors in multivariate analyses, babies given prolonged antibiotics had increased mortality (odds ratio (OR) 1.46, 95% confidence interval (CI)=1.19 to 1.78). In addition, of those babies intubated for 7 days, prolonged antibiotics were associated with increased mortality (OR 1.42, 1.13 to 1.80), and increased incidence of necrotising enterocolitis (OR 1.50, 1.11 to 2.02). Only 22 babies needed to be treated (Number Needed to Harm) with prolonged antibiotics for one extra baby to die, or develop NEC. Causes of death were unspecified, and mechanism of harm from prolonged antibiotics remains unknown. However, the authors speculate that alteration of bowel microflora may contribute. Of particular interest, a Cochrane review reported that probiotics can protect newborns against NEC and death, perhaps through a similar mechanism. (http://www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD005496/frame.html). Link: http://www.pediatrics.org/cgi/content/full/123/1/58 Submitted by: David Isaacs, davidi@chw.edu.au Warts are known to be common in primary schoolchildren. Generations of schoolchildren have been forced by schools to wear footwear at the swimming pool or in showers to prevent transmission. A Dutch study examined the hands and feet of 1465 children aged 4 to 12 years and found that 33% of children had warts. Plantar warts were commonest (20% of children), while 9% had hand warts and 4% had both. A questionnaire, answered by 76% of parents, found no correlation between environmental factors connected to barefoot activities, public showers or swimming pool visits, and the presence of warts. Children with a family member with warts had twice the risk of having warts and the other risk factor was a high prevalence of warts in the child's school class. There are good safety reasons for children to wear footwear in showers and by the pool, but preventing warts is not one of them. Submitted by David Isaacs (davidi@chw.edu.au)

Immunization status and risk factors of migrant children in densely populated areas of Beijing, China

Objective To properly evaluate the immunization status and determine risk factors of migrant children in 23 densely populated towns and townships in Beijing. Methods A household cluster sampling survey was implemented and standard face-to-face interviews were conducted with 1820 migrant children aged 12–35 months. Demographic characteristics of the child and primary caregiver, the child's migrant characteristics, the primary caregiver's knowledge and attitude toward immunization, information about immunization services provided by the local clinic, and the child's immunization history were obtained. Weighted up-to-date (UTD) and age-appropriate immunization rates for the following four vaccines were assessed: three doses of diphtheria, tetanus and pertussis combined vaccine (DTP); three doses of oral poliomyelitis vaccine (OPV); three doses of hepatitis B vaccine (HepB); and one dose of Measles-containing vaccine (MCV). Weighted UTD and age-appropriate immunization rates for the overall series of these four vaccines (the 3:3:3:1 immunization series) were also estimated. Risk factors for not being UTD, being invalid and being delayed for the 3:3:3:1 immunization series were explored using both single-level and multi-level multinomial logistic regression models. Results For each antigen, the weighted UTD immunization rate was above 83%, but the age-appropriate immunization coverages for HepB, OPV, DPT, and MCV were only 45.6%, 49.6%, 50.8% and 54.7%, respectively. The 1st dose was most likely to be invalid or delayed within HepB, OPV and DPT series. For the 3:3:3:1 immunization series, the weighted UTD and age-appropriate immunization rates were 78.1% and 20.5%, respectively. Immunization status of migrant children tended to be homogenous within a village and therefore, multi-level model was more appropriate for assessing risk factors. Besides demographic characteristics, several other factors were significantly associated with age-appropriate immunization coverage. These factors included: the child's migrant characteristics; the primary caregiver's awareness of the importance of vaccination, and outreach services provided by immunization clinics including notification services and supplementary immunization activities (SIAs). The frequency and duration of clinical immunization sessions significantly influenced the UTD immunization rate but not the age-appropriate immunization rate. The degree of the primary caregiver's satisfaction with clinic services and convenience to vaccination clinic had no impact on the child's immunization status. Conclusion Alarmingly low age-appropriate immunization coverage of migrant children in densely populated areas demanded immediate intervention. Community context was an important factor to a migrant child's vaccination status and should be considered when taking measures. Strategies to strengthen outreach immunization service need to be developed to effectively improve the age-appropriate immunization coverage of migrant children.

Using PCR and culture methods for Mycoplasma testing

Mycoplasma contaminants can be considered important not only for their roles as pathogens but also they may indicate that insufficient care has been taken during vaccine manufacture or quality control. The purpose of this study was to test the poliomyelitis vaccines for Mycoplasma by culture and polymerase chain reaction (PCR) methods. During 2008 to 2009, a total of 47 lots of oral poliomyelitis vaccines were produced by Razi Vaccine and Serum Research Institute (RVSRI) in Iran. They were evaluated by culture and PCR for detection of Mycoplasma. In culture method, PPLO broth and PPLO agar medium were used and in PCR method, universal primers that were selected from the region 16S ribosomal RNA of Mycoplasmas were applied. In culture method, no changes on pH and color in PPLO broth tubes and no colony growth on PPLO agar plates were seen. In PCR method, Mycoplasma DNA was not detected in any of the tested vaccines. It was concluded that the current culture method for Mycoplasmas is reliable to detect viable Mycoplasmas in oral poliomyelitis vaccines, but our results confirmed the use of PCR assay as an efficient supplement to culture method.

Antibody persistence in UK pre-school children following primary series with an acellular pertussis-containing pentavalent vaccine given concomitantly with meningococcal group C conjugate vaccine, and response to a booster dose of an acellular pertussis-containing quadrivalent vaccine

This open-label, randomised, controlled study examined antibody persistence following infant vaccination at 2, 3 and 4 months of age with either an acellular pertussis, diphtheria, tetanus, inactivated poliovirus, Haemophilus influenzae type b (DT 5aP-IPV-Hib; Pediacel ®) or a whole-cell pertussis (DTwP//Hib + oral poliomyelitis vaccine [OPV]) combination vaccine, given concomitantly with meningococcal serogroup C conjugate (MCC) vaccine, followed by a Hib booster at approximately 15 months of age. Immune responses were sustained to 3.5–4.5 years of age for all antigens contained in Pediacel. Administration of an acellular pertussis-containing quadrivalent pre-school booster (Td 5ap-IPV; Repevax ®), with or without measles, mumps and rubella (M-M-R™II) vaccine, induced robust antibody responses indicative of protection, regardless of the vaccine used for the primary series. Reactogenicity of Repevax was acceptable and consistent with previous experience.

Effectiveness of inactivated poliomyelitis vaccine for primary vaccination

To study the immunological effectiveness of inactivated poliomyelitis vaccine (IPV) for children's primary vaccination in China and to compare with the oral poliomyelitis vaccine (OPV) used in routine vaccination. The 2-month-old children were randomly immunized with IPV and OPV, with 208 subjects in each group. The pre- and post-vaccination blood samples were collected. Micro-neutralization method was used to measure the antibody response against 3 types of polioviruses. chi2 test was used to evaluate the statistical difference of protection rates between two groups, while the antibody titers were transformed by logarithm and analyzed by Z-test. P < 0.05 was always used to define the significance of analysis. After 3 doses of immunization, the protection rates in IPV group reached to 100.0% (186/186), 97.3% (181/186), 98.9% (184/186) for poliovirus type 1, 2, 3, respectively, and in OPV group were 97.4% (188/193), 100.0% (193/193), 95.3% (184/193), respectively. The geometry mean titers (GMTs) were 151.2, 86.7, 211.3 for IPV group; and 1089.5, 538.2, 203.7 for OPV group. IPV showed comparable protection rates with OPV for type 1 and 2 (chi2(I) = 2.991, P = 0.084; chi2(II) = 3.512, P = 0.061), while type 3 was higher than OPV (chi2(III) = 4.143, P = 0.042). The GMT of type 1 and 2 in IPV group were lower than OPV group (Z(I) = 12.537, P = 0.000; Z(II) = 13.415, P = 0.000), while the GMT of type 3 were comparable in two groups (Z(III) = 0.067, P = 0.947). IPV showed roughly comparable immunological effectiveness in young children. The protection rates for type 1 and 2 were similar to OPV, while type 3 was higher than in OPV group; In terms of GMT,type 1 and 2 in IPV group were lower than OPV, but type 3 were comparable to OPV group.

Reversion to the Neurovilurent Genome Sequence of Polio Vaccine Virus Isolated from Community-Acquired Meningitis

Neurologic complication associated with the use of live attenuated oral poliomyelitis vaccine is uncommon, but vaccine-associated paralytic poliomyelitis in recipients or contacts has sometimes been reported. We report here a com- munity-acquired aseptic meningitis case and the genetic investigation of the isolated poliovirus type 2. The results of the genetic analysis indicate that the mechanism of this meningitis could be the result of the reversion of the virus during rep- lication in the other vaccine recipients, suggesting a quest for revising the current vaccination program.

Age at presentation for infant immunization in Nigeria: Implications for hepatitis B immunization

Hepatitis B virus (HBV) infects 2 billion people worldwide. It is highly endemic in sub-Saharan Africa, with the majority of infections acquired during early childhood. Globally, over 25% of people who acquire HBV infection in childhood develop cirrhosis and hepatocellular carcinoma in adulthood. In Nigeria, the prevalence rate of HBV infection in children ranges from 19.3% to 46%. The hepatitis B vaccine has been available since 1982 for the prevention of HBV infection, and is recommended by the World Health Organization (WHO) for inclusion in the routine immunization of all children using one of three schedules. The hepatitis B vaccination schedule as adopted by the Expanded Programme on Immunization (EPI) and the Nigerian National Programme on Immunization (NPI) requires three contacts: as soon as possible after birth, at 6 weeks of age and at 14 weeks of age. This schedule is the second of the WHO options. It is also recommended that Bacille Calmette Guerin and oral poliomyelitis vaccine should be given at birth. Nigeria approved the inclusion of hepatitis B vaccine in the national immunization programme in 1995, but the vaccine only became widely available in 2004. Age at commencement of the hepatitis B immunization schedule has been

Long-term anti-rabies antibody persistence following intramuscular or low-dose intradermal vaccination of young Vietnamese children

Vietnamese children received purified Vero cell rabies vaccine 1 year after a primary series (Y0) and again 5 years later (Y5), either as intramuscular or 1/5th dose intradermal injections concomitant with diphtheria, tetanus, pertussis and oral poliomyelitis vaccines. Antibody levels were assayed annually for 5 years. All subjects in both groups had anti-rabies antibody titres considered protective after the Y0 booster. Rabies seroprotection rates and geometric mean titres gradually decreased similarly in both groups. Seroprotection after the Y5 booster was 100% in both groups. Satisfactory immunogenicity, long-term antibody persistence and an anamnestic response were conferred by both routes, greatly simplifying any future post-exposure prophylaxis.

Segurança, imunogenicidade e eficácia protetora de duas doses da vacina RIX4414 contendo rotavírus atenuado de origem humana

OBJECTIVE: To determine the safety, immunogenicity and efficacy of two doses of rotavirus vaccine in healthy Brazilian infants. METHODS: A randomized, multicenter, double-blind, placebo-controlled trial was conducted in Brazil, Mexico and Venezuela. Infants received two oral doses of vaccine or placebo at 2 and 4 months of age, concurrently with routine immunizations, except for oral poliomyelitis vaccine (OPV). This paper reports results from Belem, Brazil, where the number of subjects per group and the viral vaccine titers were: 194 (104.7 focus forming units - FFU), 196 (105.2 FFU), 194 (105.8 FFU) and 194 (placebo). Anti-rotavirus (anti-RV) antibody response was assessed in 307 subjects. Clinical severity of gastroenteritis episodes was measured using a 20-point scoring system with a score of > 11 defined as severe GE. RESULTS: The rates of solicited general symptoms were similar in vaccine and placebo recipients. At 2 months after the second dose, a serum IgA response to RV occurred in 54.7 to 74.4% of vaccinees. No interference was seen in the immunogenicity of routine vaccines. Vaccine efficacy against any rotavirus gastroenteritis (RVGE) was 63.5% (95%CI 20.8-84.4) for the highest concentration (105.8 FFU). Efficacy was 81.5% (95%CI 44.5-95.4) against severe RVGE. At its highest concentration (105.8 FFU), RIX4414 provided 79.8% (95%CI 26.4-96.3) protection against severe RVGE by G9 strain. CONCLUSIONS: RIX4414 was highly immunogenic with a low reactogenicity profile and did not interfere with seroresponse to diptheria, tetanus, pertussis, hepatitis B and Hib antigens. Two doses of RIX4414 provided significant protection against severe GE caused by RV.

Safety, immunogenicity, and protective efficacy of two doses of RIX4414 live attenuated human rotavirus vaccine in healthy Brazilian infants

To determine the safety, immunogenicity and efficacy of two doses of rotavirus vaccine in healthy Brazilian infants. A randomized, multicenter, double-blind, placebo-controlled trial was conducted in Brazil, Mexico and Venezuela. Infants received two oral doses of vaccine or placebo at 2 and 4 months of age, concurrently with routine immunizations, except for oral poliomyelitis vaccine (OPV). This paper reports results from Belém, Brazil, where the number of subjects per group and the viral vaccine titers were: 194 (10(4.7) focus forming units - FFU), 196 (10(5.2) FFU), 194 (10(5.8) FFU) and 194 (placebo). Anti-rotavirus (anti-RV) antibody response was assessed in 307 subjects. Clinical severity of gastroenteritis episodes was measured using a 20-point scoring system with a score of >or= 11 defined as severe GE. The rates of solicited general symptoms were similar in vaccine and placebo recipients. At 2 months after the second dose, a serum IgA response to RV occurred in 54.7 to 74.4% of vaccinees. No interference was seen in the immunogenicity of routine vaccines. Vaccine efficacy against any rotavirus gastroenteritis (RVGE) was 63.5% (95%CI 20.8-84.4) for the highest concentration (10(5.8) FFU). Efficacy was 81.5% (95%CI 44.5-95.4) against severe RVGE. At its highest concentration (10(5.8) FFU), RIX4414 provided 79.8% (95%CI 26.4-96.3) protection against severe RVGE by G9 strain. RIX4414 was highly immunogenic with a low reactogenicity profile and did not interfere with seroresponse to diphtheria, tetanus, pertussis, hepatitis B and Hib antigens. Two doses of RIX4414 provided significant protection against severe GE caused by RV.

WHO is to add a monovalent oral poliomyelitis vaccine to its existing polio eradication regimen in India,

WHO is to add a monovalent oral poliomyelitis vaccine to its existing polio eradication regimen in India,