Oral Live-attenuated Rotavirus Vaccine Research Articles

Analysis of vaccination situation of orial live attenuated rotavirus vaccine (LLR strain) among children in 6 provinces of China

Objective: To analyze vaccination situation of oral live attenuated rotavirus vaccine (LLR strain) among children from six provinces in China. Methods: In 2014, we selected 12 counties in Guangdong, Jiangsu, Chongqing, Jiangxi, Heilongjiang and Gansu provinces by using stratified cluster random sampling method and extract information of children born from January 1, 2008 to December 31, 2012 from Children's Immunization Information System. We investigated ten children of each birth cohort in each county by checking the vaccination certification, and a total of 606 children were investigated. A survey was conducted to check the information of the children's vaccination certification with the data of Children's Immunization Information System by questionnaire including the basic information (province, county, name, gender, birth date, etc) and the rotavirus vaccination (vaccination date, dose, etc) to analyze the rotavirus vaccination situation. Results: 340 of 606 children were male. There were 121, 124, 122, 119 and 120 children born in 2008-2012, respectively. The proportions of the first and the second dose of rotavirus vaccination were 32.8% (199) and 9.7% (59). The proportion of the third dose of rotavirus vaccination among children born between 2008 and 2010 was 3.5% (13) since children born in 2011 and 2012 did not reach the age of third dose vaccination. The proportion of the first dose of rotavirus vaccination in high, middle and low per capita disposable income areas was 45.0% (91), 37.7% (77) and 15.5% (31) respectively (χ(2)= 43.15, P<0.001). Among 199 children vaccinated with the first dose of vaccine, the vaccination age mainly concentrated in 2 to 21 months, of which the peak was 5 to 13 months (66.8%, 133). The intervals between 2 doses of vaccination were mainly from 12 to 13 months (42.4%, 25) among the 59 children who received at least 2 doses of vaccine. In the 13 children vaccinated with 3 doses, the intervals between the second and the third dose were 12 months (5). Of the 271 doses of rotavirus vaccine vaccinated during 2008-2014, 34.7% (94 doses) were vaccinated in June-August, 88 were vaccinated simultaneously with 18 other vaccines, accounting for 32.5% of the total. Of the 18 other vaccines, inactivated vaccines such as diphtheria vaccine (30 doses), Hib vaccine (14 doses), group A meningitis vaccine (10 doses) were predominant. Conclusion: The proportion of rotavirus vaccination was low and the vaccination age was relatively late. The vaccination mode was different from the recommendation of WHO. It is recommended that routine immunization of rotavirus vaccines should be carried out in early-months of children.

Immunization coverage of oral live attenuated rotavirus vaccines and its influencing factors among children under 5 years old in Jinshan District of Shanghai

Objective To investigate the immunization coverage of oral live attenuated rotavirus vaccines and its influencing factors among children under 5 years old in Jinshan District of Shanghai in order to provide references for optimizing vaccination management in this area. Methods A cross-sectional study was conducted in 6 community vaccination clinics randomly selected from 12 vaccination clinics in Jinshan District. In each selected clinic, 145 children under 5 years old were continuously recruited. Information on immunization status, demographics of children, family socioeconomic status and parents′ knowledge of vaccination were collected through questionnaire interview. Logistic regression was used to analyze factors influencing immunization status by using SPSS22.0. Results Among the 863 participating children, the immunization coverage rate of oral live attenuated rotavirus vaccines was 61.07%. Multivariate analysis revealed that children having an urban registration status (OR=2.21), better family income (OR=1.47) and parents with high recognition of rotavirus diarrhea (OR=8.56) and stronger intention to following doctor′s suggestions (OR=1.96) were more likely to accept oral live attenuated rotavirus vaccines, while those from families with a medical professional were less likely to be vaccinated (OR=0.57). Conclusion The immunization coverage rate of oral live attenuated rotavirus vaccines among children in Jinshan District were influenced by various factors such as children′s household registration status, household income, parents′ knowledge regarding vaccination and doctors′suggestions. Health education on immunization should be strengthened and tailor-made to improve the coverage of oral rotavirus vaccination. Key words: Children; Oral live attenuated rotavirus vaccine; Immunization coverage rate; Influencing factor

Introduction of a new Rotavirus vaccine: Initial results of uptake and impact on laboratory confirmed cases in Anglia and Essex, United Kingdom, July 2015

abstractRotavirus gastroenteritis accounts for an estimated 130,000 GP consultations and 13,000 hospitalisations for children under 5 y old each year in England and Wales. In July 2013, an oral live attenuated rotavirus vaccine (Rotarix®) was introduced into the UK infant immunisation program as a 2 dose schedule at 2 and 3 months of age. We collected vaccination uptake from October 2013 to March 2015 and laboratory confirmed cases data on children under the age of 5 y from 1 January 2004 to 31 May 2015. The vaccine uptake rates and laboratory confirmed cases were compared to provide evidence of the impact of this vaccination program. Vaccine uptake rates were available from sentinel data with between 91–98% of GP practices in Anglia and Essex providing data every month. These data showed from February 2014 to March 2015 between 90–92% of infants received the recommended 2 doses of Rotarix® each month. The numbers of rotavirus cases reported by laboratories decreased on average by 82% in the post vaccination seasons. The mean number of cases reported in weeks 1–22 for 2004–2013 in Anglia and Essex was 1,318. For the same period in 2014, 256 cases were reported and initial data for 2015 report 226 cases. In the first 5 months 2014 the greatest reduction in cases (89%) was seen in those under 1 yr (who would have been directly affected by vaccination) with case numbers falling to 59 from a mean 537 cases in the equivalent period for 2004–2013. Initially data suggests a 92% reduction in 2015 compared to the same pre-vaccination periods. For those aged 1 to <5 y who would not have been vaccinated, a reduction of 75% was also evident in 2014 and 77% in 2015, suggesting indirect protection in this group. In conclusion, initial results following the introduction of the Rotavirus vaccine clearly indicates a very good uptake of the vaccine and a significant reduction in the numbers of laboratory confirmed cases.

Human rotavirus virus-like particle vaccines evaluated in a neonatal gnotobiotic pig model of human rotavirus disease

The authors discuss here rotavirus-like particle vaccines as an alternative approach to oral live-attenuated rotavirus vaccine and their efficacy in a gnotobiotic pig model. Rotavirus virus-like particles (VLPs) were evaluated in different doses, and routes of administration, and combined with live-attenuated virus and adjuvants. A VLP vaccine composed of rotavirus VP2 and VP6 was immunogenic in gnotobiotic pigs when inoculated intranasally; however, this vaccine failed to confer protection. A combination of oral attenuated human rotavirus and intranasal 2/6VLP vaccines conferred immunogenicity, partial protection against a human rotavirus challenge and induced IFN-γ-producing T cells in the ileum of pigs with similar frequencies to human rotavirus infection. Vaccination through a combination of mucosal inductive sites and live-attenuated vaccine combined with VLP vaccines was the most effective regimen, compared with the use of a single route or a single vaccine alone. However, if formulated with neutralizing antigens, VLP vaccines may constitute a better approach in a high maternal antibody scenario.

Early observations in the use of oral rotavirus vaccination in infants with functional short gut syndrome

Universal vaccination with an oral live-attenuated rotavirus vaccine at 2, 4 and 6 months of age was introduced in Australia in July 2007. There are no data on the short-term effects of vaccination for those infants most at risk of severe complications from rotavirus infection. The aim of this study was to describe the effects of rotavirus vaccination on weight gain and gastrointestinal losses in infants with functional short gut syndrome secondary to an ileostomy. A retrospective review of all infants with an ileostomy who received RotaTeq while hospitalised at the Royal Children's Hospital, Melbourne from July 2007 to July 2009 was performed. Daily data were collected from 1 week before to 2 weeks after vaccination. The data included type and volume of feeds, ileostomy losses, need for fluid replacement of ileostomy losses, weight, temperature, urine sodium, stool culture, suspected and confirmed sepsis. Nine infants (age at first RotaTeq 61-99 days) were identified. The median (range) gestational age was 26 (24, 38) completed weeks and birthweight was 737 (620, 2714) grams. Compared to the day of vaccination, the median (range) ileostomy losses 1 week before, 1 and 2 weeks after vaccination were -1.1 (-13.6, 4.9) mL/kg/day, 2 (-11.1, 25.0) mL/kg/day and 2.4 (-15.7, 27.2) mL/kg/day, respectively. One infant developed severe stomal losses after vaccination. Overall, rotavirus vaccination did not alter weight gain, temperature or urinary sodium. In this small series, oral live-attenuated rotavirus vaccination of infants with high-output ileostomy was tolerated in most cases.

Live attenuated polio vaccine and the risk of intussusception.

Since suspicion has been raised that administration of an oral live attenuated rotavirus vaccine may increase the risk of intussusception in young children, there has been concern about the possible effects of oral polio vaccine. The aim of the study was to evaluate the relationship between oral attenuated polio vaccine and intussusception in children below the age of 1 year. We conducted a nested case-control analysis based on data from the General Practice Research Database which encompassed 133 children who developed documented intussusception during the first year of life and 515 controls. The time from oral polio vaccine to the index date was similar in cases and controls. Relative risk estimates for intussusception ranged from 0.7 (95% CI 0.2, 2.1) for babies whose last oral polio vaccine was given 29-35 days before their index date to 1.0 (95% CI 0.4, 2.3) for those whose last oral polio vaccine was given 15-21 days before their index date (compared with babies vaccinated more than 43 days before their index date). There is no suggestion that oral polio vaccine increases the risk for intussusception.

Rotavirus vaccines must perform in low-income countries too

Every year rotavirus diarrhoea causes well over half a million deaths, more than 25 million outpatient visits, and more than 2 million hospital admissions in children aged under 5 years. Although most rotavirus-related deaths occur in low-income countries, 220 000 children a year in industrialised countries are admitted to hospital.1 Vaccines are the only public-health intervention with the potential to control rotavirus disease and, in today's Lancet, Timo Vesikari and colleagues report on a trial of an oral live-attenuated rotavirus vaccine in 3994 European infants.

Live attenuated polio vaccine and the risk of intussusception

Aims Since suspicion has been raised that administration of an oral live attenuated rotavirus vaccine may increase the risk of intussusception in young children, there has been concern about the possible effects of oral polio vaccine. The aim of the study was to evaluate the relationship between oral attenuated polio vaccine and intussusception in children below the age of 1 year.Methods We conducted a nested case‐control analysis based on data from the General Practice Research Database which encompassed 133 children who developed documented intussusception during the first year of life and 515 controls.Results The time from oral polio vaccine to the index date was similar in cases and controls. Relative risk estimates for intussusception ranged from 0.7 (95% CI 0.2, 2.1) for babies whose last oral polio vaccine was given 29‐35 days before their index date to 1.0 (95% CI 0.4, 2.3) for those whose last oral polio vaccine was given 15‐21 days before their index date (compared with babies vaccinated more than 43 days before their index date).Conclusions There is no suggestion that oral polio vaccine increases the risk for intussusception.

Factors Affecting Antibody Response of Newborns to Repeated Administrations of the Rotavirus Vaccine RIT 4237

SummaryThe safety and immunogenicity of repeated doses of RIT 4237. an oral live attenuated rotavirus vaccine of bovine origin, as well as the influence of gastric acidity and maternal antibodies on the vaccine “take rate” were studied in newborns. The vaccine was given orally on the first day of life, at 1 month, and at 2 months of age. Fifty‐seven newborns entered the study but only 36 completed the trial. No adverse reaction was observed after vaccination. Immune responses were evaluated by titrating pre‐and postvaccination serum antibodies to RIT 4237 by a neutralization technique. Eight of 43 (18.6%) tested infants responded to the first dose of vaccine. Subsequently another six and 11 infants responded to the second and third dose, respectively. The total cumulative response after the third dose was 23 of 36 vaccinees (63.9%). The geometric mean neutralizing antibody titers was lower in responders than in nonre‐sponders before the first dose of vaccine indicating that maternal antibodies interfered with vaccine “take.” Since the RIT 4237 strain is acid sensitive, gastric pH was measured at the time of each vaccination. Mean pH values in responders were not significantly different than those found in nonresponders. Therefore, vaccine failures cannot be due to inactivation of the rotavirus vaccine in the stomach but instead they can be attributed to high levels of maternal antibodies. At each vaccination, additional subjects seroconverted. Therefore, a multiple dose scheme is advisable to obtain an optimal immune response.

Factors affecting antibody response of newborns to repeated administrations of the rotavirus vaccine RIT 4237.

The safety and immunogenicity of repeated doses of RIT 4237, an oral live attenuated rotavirus vaccine of bovine origin, as well as the influence of gastric acidity and maternal antibodies on the vaccine "take rate" were studied in newborns. The vaccine was given orally on the first day of life, at 1 month, and at 2 months of age. Fifty-seven newborns entered the study but only 36 completed the trial. No adverse reaction was observed after vaccination. Immune responses were evaluated by titrating pre- and postvaccination serum antibodies to RIT 4237 by a neutralization technique. Eight of 43 (18.6%) tested infants responded to the first dose of vaccine. Subsequently another six and 11 infants responded to the second and third dose, respectively. The total cumulative response after the third dose was 23 of 36 vaccinees (63.9%). The geometric mean neutralizing antibody titers was lower in responders than in nonresponders before the first dose of vaccine indicating that maternal antibodies interfered with vaccine "take." Since the RIT 4237 strain is acid sensitive, gastric pH was measured at the time of each vaccination. Mean pH values in responders were not significantly different than those found in nonresponders. Therefore, vaccine failures cannot be due to inactivation of the rotavirus vaccine in the stomach but instead they can be attributed to high levels of maternal antibodies. At each vaccination, additional subjects seroconverted. Therefore, a multiple dose scheme is advisable to obtain an optimal immune response.