ABSTRACT
BACKGROUND: Enterovirus (EV) A71 and coxsackievirus (CV) A16 were the most frequent serotypes involved in hand, foot, and mouth disease (HFMD) outbreaks throughout Asia. In the past 5 years, however, CV-A6 has emerged as a new important pathogen worldwide, and more severe and extensive dermatologic presentations has been reported. OBJECTIVES: Identify the clinical spectrum for atypical HFMD and enterovirus serotypes in Belém, Pará, Amazon region of northern Brazil. STUDY DESIGN: A prospective ambulatory clinic-based surveillance conducted from January to June 2019, involving patients under 15 years with symptoms of HFMD. Stool, serum, oropharyngeal, and skin swab samples were analyzed. Real-time RT-PCR was performed to detect the viral genome of enteroviruses. Positive specimens were submitted to semi-nested PCR. Physical examinations and demographic data were recorded on a standardized form. RESULTS: 48 patients with symptoms of HFMD were included in the study and collected all samples according to protocol. Enteroviruses were detected in 83 % of patients. An atypical form of HFMD with vesiculobullous exanthema was present in 70 % (28/40); desquamation of the palms and soles detected in 90 % (36/40) and onychomadesis in 30 % (12/40) of patients. The serotype was identified in 22 patients, CV- A6 occurred in 81.8 % of them. CONCLUSION: This is the first ambulatory surveillance and virologic investigation involving HFMD performed in outpatients from Amazon region, Brazil. The detection of CV-A6 was related to atypical forms HFMD. Desquamation of the palms and soles and nail changes occurred with frequency, such as a late sequel in the HFMD disease.
Subject(s)
Enterovirus Infections/epidemiology , Enterovirus/isolation & purification , Hand, Foot and Mouth Disease/epidemiology , Adolescent , Antibodies, Viral/blood , Brazil/epidemiology , Child , Child, Preschool , Disease Outbreaks , Enterovirus/classification , Enterovirus/genetics , Female , Genome, Viral , Genotype , Humans , Infant , Infant, Newborn , Male , Phylogeny , Prospective Studies , Serogroup , Skin Diseases, Vesiculobullous/diagnosis , Skin Diseases, Vesiculobullous/epidemiology , Skin Diseases, Vesiculobullous/virologyABSTRACT
BACKGROUND: Rotavirus antigenemia and RNAemia (the presence of rotavirus RNA in serum) have been commonly identified among paediatric patients with acute gastroenteritis. In this study we examined the association between rotavirus antigenemia and clinical features, and sought to determine the genotypes of rotaviruses detected in paired stool and serum samples. METHODS: Paired stool and serum samples were obtained from children hospitalised for acute gastroenteritis in Belém, Brazil, between June 2012 and June 2015. The 20-point Vesikari scoring system was used to assess the disease severity upon a retrospective medical record review. Stool and serum samples were primarily screened for the presence of rotavirus antigen using a commercial ELISA assay. The rotavirus isolates from stool and serum samples were genotyped by using the classical reverse-transcriptase polymerase chain reaction (RT-PCR) and/or through nucleotide sequencing of VP4 and VP7 genes. Viral load was estimated using real-time RT-PCR. RESULTS: In total rotavirus antigen was detected in 109 (24.2%) stool samples from 451 children, whereas antigenemia occurred in 38.5% (42/109) of these patients. We demonstrated that patients positive for rotavirus RNA in paired stool and serum samples were more likely to have a higher frequency of vomiting episodes in a 24-h period (p = 0.0035). Our findings also suggested that children not vaccinated against rotavirus are more likely to develop antigenemia, as compared to those given at least one vaccine dose (p = 0.0151). G12P [8] and G2P [4] genotypes were predominant throughout the study period, accounting for 52.3% (57/109) and 27.5% (30/109) of the typed isolates, respectively. Ten stool-serum pairs could be typed for VP4 and VP7 genes. Seven of these pairs showed concordant results with G2P [4] genotype being detected in stool and serum samples, whereas discrepancies between genotypes (G2P [4]/G2P[NT] and G12P [8]/G2P[NT]) were seen in three pairs. CONCLUSIONS: Rotavirus antigenemia and RNAemia occur in a significant number of children hospitalised for acute gastroenteritis in Belém, Brazil, and may contribute to a greater disease severity, particularly translated into a greater number of vomiting episodes. This study documented a high concordance of genotypes detected in a subgroup of paired stool and serum samples.
Subject(s)
Antigens, Viral/analysis , Gastroenteritis/immunology , RNA, Viral/analysis , Rotavirus Infections/immunology , Rotavirus/immunology , Acute Disease , Antigens, Viral/blood , Brazil , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Feces/chemistry , Feces/virology , Female , Gastroenteritis/complications , Gastroenteritis/virology , Genotype , Hospitalization , Humans , Male , Prospective Studies , RNA, Viral/blood , Reverse Transcriptase Polymerase Chain Reaction , Rotavirus/genetics , Severity of Illness Index , Vomiting/etiologyABSTRACT
Species A rotavirus still remains a major cause of acute gastroenteritis in infants and young children. Globally, six genotypes (G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]) account for >90% of circulating strains; however, genotype G12 in combination with P[6] or P[9] has been detected at increasing rates. We sought to broaden our knowledge about the rotavirus strains circulating during the early post-vaccine-introduction period. Stool samples were obtained from children hospitalised for acute gastroenteritis in Belém, Northern Brazil, from May 2008 to May 2011 and examined by reverse transcription polymerase chain reaction and nucleotide sequencing. A total of 122 out of the original 1076 rotavirus strains were judged to be non-typeable in the first analysis and were therefore re-examined. G2P[4] was the most prevalent genotype (58.0%), followed by G1P[8] (16.9%), and G12P[6] (7.5%). G12P[6] strains were identified at similar rates during the first (2.5%) and second (3.9%) years, and the rate jumped to 15.6% in the third year. Analysis of VP7 sequences of the G12P[6] strains showed that they belonged to lineage III. In addition, co-circulating G12P[6] strains displaying long and short RNA patterns were found to belong to the Wa-like and DS-1-like constellation, respectively. Additional unusual circulating strains G12P[9] and G3P[9] were also identified. This hospital-based study showed a high prevalence of G12P[6] strains in the third year of surveillance. Our results highlight the need for continuous longitudinal monitoring of circulating rotavirus strains after introduction of rotavirus vaccines in Brazil and elsewhere.
Subject(s)
Gastroenteritis/virology , Rotavirus/genetics , Antigens, Viral/immunology , Brazil , Child , Child, Hospitalized , Gastroenteritis/immunology , Genotype , Humans , Molecular Epidemiology/methods , Phylogeny , Prevalence , RNA, Viral/genetics , Rotavirus/immunology , Rotavirus Infections/immunology , Rotavirus Infections/virology , Rotavirus Vaccines/immunology , Sequence Analysis, DNA/methodsABSTRACT
Enteric adenovirus (AdV), sapovirus (SaV), and human astrovirus (HAstV) are important pathogens involved in the gastroenteritis etiology. In this study, a total of 219 fecal samples and sera were collected from children hospitalized for acute gastroenteritis (AGE) in two large pediatric hospitals in Belém, from March 2012 to April 2015. The samples were analyzed by polymerase chain reaction (PCR) for AdV and HAstV (astrovirus) detection, and Nested-PCR and qPCR for SaV detection. AdV was detected in 50.2% (110/219) of the cases, with 42.7% (47/110) being sequenced and classified as: species F (63.9% - 30/47), A (4.2% - 2/47), B (6.4% - 3/47), C (17.1% - 8/47), D (4.2% - 2/47), and E (4.2% - 2/47). Of the 110 AdV-positive feces samples, 80 paired sera presented sufficient amounts and were also tested for this virus, of which 51 (63.7%) showed positive results and 26 (70.3%) pairs (feces plus sera) presented concordant results after sequencing being classified as: species F (21/26; 80.8%), A (1/26; 3.8%), B (1/26; 3.8%), and C (3/26; 11.5%). Overall, HAstV rate in the feces samples was 1.8% (4/219), including both HAstV-1a (2/4; 50%) and HAstV-2c (2/4; 50%). SaV was detected in 4.6% (10/219) of the fecal samples, out of which 50% (5/10) of the positive samples were characterized into the genogroups GI.1 (1), GI.2 (2), and GII.4 (2). These findings highlighted the important contributions of AdV, HAstV, and SaV in the enteric virus spectrum in our region and showed the high genetic diversity of AdV. In addition, it demonstrated for the first time in Brazil, the circulation of AdV in the serum of hospitalized children with AGE.
Subject(s)
Adenoviridae Infections/epidemiology , Gastroenteritis/virology , Genetic Variation , Viremia/epidemiology , Acute Disease/epidemiology , Adenoviridae/genetics , Adenoviridae Infections/virology , Astroviridae Infections/epidemiology , Astroviridae Infections/virology , Brazil/epidemiology , Caliciviridae Infections/epidemiology , Caliciviridae Infections/virology , Child , Child, Preschool , Diarrhea/epidemiology , Diarrhea/virology , Female , Gastroenteritis/epidemiology , Genotype , Hospitalization , Humans , Infant , Infant, Newborn , Male , Mamastrovirus/genetics , Phylogeny , Sapovirus/geneticsABSTRACT
BACKGROUND: Rotavirus (RV) vaccine, Rotarix, was introduced into the Brazil national immunization program in 2006. To estimate population-level vaccine effect, we conducted a time-trend analysis on all-cause gastroenteritis (GE)-related death certificate-reported deaths (DCRDs), hospital deaths (HDs) and hospitalizations trends in <5-year-olds before and after RV vaccine introduction. METHODS: National level all-cause GE-related death certificate [Mortality Information System] and admission (Hospital Information System) data were aggregated and analyzed. Negative-binomial regression models (adjusting for age, year and region) compared DCRDs, HDs and hospitalization trends in <5-year-olds between baseline (2001-2005) and postvaccine introduction periods (Mortality Information System: 2007-2009 and Hospital Information System: 2007-2010). Negative-binomial regression models were fitted to data for each outcome before 2006, and the predicted annual frequencies of each outcome were plotted against corresponding observed annual frequencies. RESULTS: During the postvaccine introduction period, there was an overall age-independent GE-related DCRDs reduction (20.9%, P = 0.04) observed in children <5 years of age; a reduction was also seen in infants <1 year of age (20.8%, P = 0.003). Age-independent GE-related HDs and hospitalizations reductions (57.1%, P < 0.0001 and 26.6%, P < 0.0001, respectively) were observed in <5-year-olds; HDs reductions were also observed for each age group (<1-year-olds: 55.0%, P < 0.0001 and 1- to <5-year-olds: 59.5%, P < 0.0001). Observed annual frequencies of GE-related DCRDs, HDs and hospitalizations were lower than the predicted value in each age group in all years after 2006. CONCLUSIONS: GE-related DCRDs, HDs and hospitalizations were significantly reduced in <1 and in 1- to <5-year-old Brazilian children after Rotarix introduction, which provides additional evidence of the direct and indirect population-level effect of RV vaccination on GE-related mortality and morbidity in children.
Subject(s)
Gastroenteritis/epidemiology , Gastroenteritis/mortality , Hospitalization , Rotavirus Vaccines/administration & dosage , Brazil/epidemiology , Child, Preschool , Female , Gastroenteritis/prevention & control , Humans , Immunization Programs , Incidence , Infant , Infant, Newborn , Male , Retrospective Studies , Survival AnalysisABSTRACT
In March 2006, Brazil introduced the monovalent rotavirus (RV) vaccine (Rotarix™) into the public sector. This study assessed the severity of rotavirus gastroenteritis (RVGE) according to the vaccination status among hospitalized children. We identified 1023 RVGE episodes among not vaccinated (n = 252), partially vaccinated (n = 156) and fully vaccinated (n = 615) children. Very severe gastroenteritis (scored ≥ 15) was reported in 16.7, 17.9 and 13.5% of not vaccinated, partially vaccinated and fully vaccinated children, respectively. There was a trend for a shorter duration of RV diarrhoea among vaccinated children than in not vaccinated children (p = 0.07). A protective effect of vaccination was noted when mean duration of symptoms and hospital stay are analysed, comparing unvaccinated, partially vaccinated and fully vaccinated children (p < 0.05). We showed a vaccination dose effect trend, with fully vaccinated children having less-severe RVGE than not vaccinated and partially vaccinated children.
Subject(s)
Gastroenteritis/epidemiology , Gastroenteritis/prevention & control , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Rotavirus/isolation & purification , Vaccination/statistics & numerical data , Brazil/epidemiology , Child , Child, Preschool , Female , Gastroenteritis/virology , Humans , Immunization Programs , Incidence , Male , Population Surveillance , Prospective Studies , Rotavirus Infections/epidemiology , Rotavirus Vaccines/immunology , Severity of Illness IndexABSTRACT
The monovalent human rotavirus (RV) vaccine, RIX4414 (Rotarix™, GlaxoSmithKline Biologicals) was introduced into Brazil's Expanded Program on Immunization in March 2006. One year after vaccine introduction, the G2P[4] strain was found to be predominant, with an apparent extinction of many non-G2 strains. This study investigated the diversity of circulating strains in the three years following RIX4414 introduction. Between May 2008 and May 2011, stool samples were collected from children aged ≥12 weeks who were hospitalized for severe lab confirmed RV-gastroenteritis (≥3 liquid or semi-liquid motions over a 24-h period for <14 days, requiring ≥1 overnight hospital stay and intravenous rehydration therapy) in Belém, Brazil. RV-gastroenteritis was detected by ELISA and the G- and P-types were determined by RT-PCR assays. During the first year of surveillance nucleotide sequencing was used for typing those samples not previously typed by RT-PCR. A total of 1,726 of 10,030 severe gastroentertis hospitalizations (17.2%) were due to severe RVGE. G2P[4] was detected in 57.2% of circulating strains over the whole study period, however it predominated during the first 20 months from May 2008 to January 2009. G1P[8] increased in the last part of the study period from May 2010 to May 2011 and represented 36.6% (112/306) of the circulating strains. G2P[4] was the predominant RV strain circulating during the first 20 months of the study, followed by G1P[8]. These findings probably reflect a natural fluctuation in RV strains over time, rather than a vaccine-induced selective pressure.
Subject(s)
Genetic Variation , Genotype , Rotavirus Infections/epidemiology , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Rotavirus/classification , Rotavirus/genetics , Brazil/epidemiology , Case-Control Studies , Child, Preschool , Epidemiological Monitoring , Feces/virology , Female , Gastroenteritis/epidemiology , Gastroenteritis/prevention & control , Gastroenteritis/virology , Humans , Infant , Male , Molecular Epidemiology , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Rotavirus/isolation & purification , Rotavirus Infections/virology , Sequence Analysis, DNA , Vaccines, Attenuated/administration & dosageABSTRACT
Before vaccine introduction in Brazil, rotavirus caused approximately 650,000 outpatient visits, 92,000 hospitalizations and 850 deaths annually among children aged <5 years. Brazil was one of the first countries to introduce rotavirus vaccination into the National Immunisation Program (NIP), in 2006, but estimated coverage (87.1%) for 2011 remained lower if compared with other routine immunizations (95%). Case-control studies reached effectiveness rates as high as 85%. Observational studies showed a significant reduction in gastroenteritis-related hospitalizations and deaths among children aged <1 year, at rates as high as 48 and 54%, respectively. There was a significant increase in the relative prevalence of G2P[4] genotype after vaccine introduction, reaching 100% of strains in some settings. A small increase in intussusception incidence was seen within 1 week following the second vaccine dose, but benefits far outweigh any potential risk. This article provides an in-depth review of postlicensure studies conducted in Brazil 7-year postintroduction.
Subject(s)
Rotavirus Infections/epidemiology , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Rotavirus Vaccines/immunology , Vaccination/methods , Vaccination/statistics & numerical data , Brazil/epidemiology , Health Policy , Hospitalization/statistics & numerical data , Humans , Immunization Programs , Incidence , Intussusception/chemically induced , Intussusception/epidemiology , Prevalence , Rotavirus Vaccines/adverse effects , Survival Analysis , Vaccination/adverse effectsABSTRACT
BACKGROUND: Noroviruses (NoVs) are a common cause of acute gastroenteritis (AGE) and until now, little is known about its ability to spread outside the gut. OBJECTIVES: We aim to investigate the role of NoVs causing viremia in children hospitalized for AGE, as well as to correlate the presence of NoVs RNA in serum with clinical severity and stool viral load. STUDY DESIGN: Paired stool and serum samples were collected from 85 pediatric patients under 6 years hospitalized for AGE from March to September 2012 in Belém, Brazil. Enzyme-linked immunosorbent assay (EIA) and reverse transcription quantitative PCR (RT-qPCR) were used to detect and quantify NoVs, respectively. Phylogenetic analysis of the partial ORF2 region was used to genotype the strains detected. RESULTS: NoVs were detected in 34.1% (29/85) of stool samples. By qRT-PCR, we found a high rate of NoVs' RNA in serum samples (34.5%) among NoVs-positive AGE cases, and was associated with a longer hospitalization (6.5 vs. 4.0 days; p=0.006), as well as with a higher stool viral load (3.9×10(11) vs. 1.1×10(11) GC/g; p=0.0472). NoVs strains were classified as GII.4 (90% of genotyped strains) and GII.7 (10%). The same genotype was found in paired stool and serum samples. CONCLUSION: Detection and molecular characterization of NoVs GII in paired stool and serum samples suggest that the dissemination of NoVs to the blood stream is not uncommon, but the role of viruses spread outside the gut and the relationship with disease severity need to be further addressed.
Subject(s)
Caliciviridae Infections/virology , Gastroenteritis/complications , Gastroenteritis/virology , Norovirus/classification , Norovirus/isolation & purification , RNA, Viral/blood , Viremia/virology , Brazil , Caliciviridae Infections/pathology , Child, Preschool , Cluster Analysis , Enzyme-Linked Immunosorbent Assay , Feces/virology , Female , Gastroenteritis/pathology , Genotype , Humans , Infant , Infant, Newborn , Male , Molecular Sequence Data , Norovirus/genetics , Phylogeny , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Sequence Analysis, DNA , Severity of Illness Index , Viral Proteins/genetics , Viremia/pathologyABSTRACT
In a large Phase III trial conducted in 10 Latin American countries, the safety and efficacy of the live attenuated monovalent rotavirus vaccine RIX4414 was evaluated in 15,183 healthy infants followed up during the first two years of life. Belém was the only site in Brazil included in this multicentre trial. The study in Belém included a subset of 653 infants who were followed up until 24 months of age for protection against severe rotavirus gastroenteritis. These subjects were randomly assigned in a 1:1 ratio to receive two doses of vaccine (n = 328) or two doses of placebo (n = 325) at approximately two and four months of age. Of the 653 enrolled infants, 23 dropped out during the study period. For the combined two-year period, the efficacy of RIX4414 was 72.3% [95% confidence interval (CI) 37.5-89.1%] against severe rotavirus-related gastroenteritis, reaching a protection rate of 81.8% (95% CI 36.4-96.6%) against circulating wild-type G9 rotavirus strains. It is concluded that two doses of RIX4414 are highly efficacious against severe rotavirus gastroenteritis in Belém during the first two years of life and provide high protection against the worldwide emergence and spread of G9P[8] strains.
Subject(s)
Antibodies, Viral/immunology , Gastroenteritis/prevention & control , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Administration, Oral , Antibodies, Viral/genetics , Child, Preschool , Double-Blind Method , Female , Gastroenteritis/virology , Genotype , Humans , Infant , Male , Rotavirus Infections/virology , Rotavirus Vaccines/adverse effects , Rotavirus Vaccines/immunology , Severity of Illness Index , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Vaccines, Attenuated/immunologyABSTRACT
In a large Phase III trial conducted in 10 Latin American countries, the safety and efficacy of the live attenuated monovalent rotavirus vaccine RIX4414 was evaluated in 15,183 healthy infants followed up during the first two years of life. Belém was the only site in Brazil included in this multicentre trial. The study in Belém included a subset of 653 infants who were followed up until 24 months of age for protection against severe rotavirus gastroenteritis. These subjects were randomly assigned in a 1:1 ratio to receive two doses of vaccine (n = 328) or two doses of placebo (n = 325) at approximately two and four months of age. Of the 653 enrolled infants, 23 dropped out during the study period. For the combined two-year period, the efficacy of RIX4414 was 72.3% [95% confidence interval (CI) 37.5-89.1%] against severe rotavirus-related gastroenteritis, reaching a protection rate of 81.8% (95% CI 36.4-96.6%) against circulating wild-type G9 rotavirus strains. It is concluded that two doses of RIX4414 are highly efficacious against severe rotavirus gastroenteritis in Belém during the first two years of life and provide high protection against the worldwide emergence and spread of G9P[8] strains.
Subject(s)
Child, Preschool , Female , Humans , Infant , Male , Antibodies, Viral/immunology , Gastroenteritis/prevention & control , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Administration, Oral , Antibodies, Viral/genetics , Double-Blind Method , Genotype , Gastroenteritis/virology , Rotavirus Infections/virology , Rotavirus Vaccines/adverse effects , Rotavirus Vaccines/immunology , Severity of Illness Index , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Vaccines, Attenuated/immunologyABSTRACT
BACKGROUND: Brazil initiated universal immunization of infants with the G1P[8] human rotavirus (RV) vaccine in March 2006. This study evaluated vaccine effectiveness (VE) against severe rotavirus gastroenteritis (RVGE) hospitalizations. METHODS: Matched case-control study conducted at 4 hospitals in Belém from May 2008 to May 2009. Cases were children hospitalized with RVGE age-eligible to have received 2 doses of the human RV vaccine (≥ 12 weeks of age and born after March 6, 2006). For each case, 1 neighborhood and 1 hospital control without gastroenteritis was selected, matching by birth date (± 8 and ± 6 weeks, respectively). Matched odds ratio of 2-dose RV vaccination in cases versus controls was used to estimate VE (1 - odds ratio × 100%). RESULTS: Of 538 RVGE cases, 507 hospital controls and 346 neighborhood controls included, 54%, 61%, and 74% had received both RV vaccine doses. VE against RVGE hospitalization was 75.8% (95% confidence interval [CI]: 58.1-86.0) using neighborhood controls and 40.0% (95% CI: 14.2-58.1) using hospital controls. VE in children 3 to 11 months and ≥ 12 months of age was 95.7% (95% CI: 67.8-99.4) and 65.1% (95% CI: 37.2-80.6) using neighborhood controls, and 55.6% (95% CI: 12.3-77.5) and 32.1% (95% CI: -3.7-55.5) using hospital controls. G2P[4] accounted for 82.0% of RVGE hospitalizations. G2P[4]-specific VE was 75.4% (95% CI: 56.7-86.0) using neighborhood controls and 38.9% (95% CI: 11.1-58.0) using hospital controls. CONCLUSIONS: Although fully heterotypic G2P[4] was the predominant RV strain, good VE was demonstrated. VE was highest in children aged 3 to 11 months. However, protection in children ≥ 12 months of age, important for optimal public health impact, was significantly sustained based on estimates obtained using neighborhood controls.
Subject(s)
Gastroenteritis/epidemiology , Gastroenteritis/prevention & control , Hospitalization/statistics & numerical data , Rotavirus Infections/epidemiology , Rotavirus Infections/prevention & control , Rotavirus Vaccines/immunology , Brazil/epidemiology , Case-Control Studies , Child, Preschool , Female , Genotype , Humans , Infant , Male , Rotavirus/classification , Rotavirus/genetics , Rotavirus/immunology , Rotavirus Vaccines/administration & dosageABSTRACT
OBJETIVO: Determinar a segurança, imunogenicidade e eficácia de duas doses da vacina contra o rotavírus em lactentes brasileiros saudáveis. MÉTODOS: Foi realizado um estudo randomizado, multicêntrico, duplo-cego e controlado por placebo no Brasil, México e Venezuela. Os lactentes receberam duas doses orais de vacina ou placebo aos 2 e 4 meses de idade, juntamente com as imunizações de rotina, exceto a vacina oral contra poliomielite (VOP). O presente estudo relata apenas os resultados obtidos em Belém, Brasil, onde o número de indivíduos por grupo e os títulos da vacina viral foram os seguintes: 194 (104,7 unidades formadoras de focos - UFF), 196 (10(5,2) UFF), 194 (10(5,8) UFF) e 194 (placebo). A resposta de anticorpos anti-rotavírus (anti-RV) foi avaliada em 307 indivíduos. A gravidade clínica dos episódios de gastroenterite (GE) foi determinada através de um escore com 20 pontos, onde um valor > 11 foi considerado como GE grave. RESULTADOS: As taxas de sintomas gerais solicitados foram semelhantes tanto nos indivíduos que receberam a vacina como naqueles a quem se administrou placebo. Aos 2 meses após a segunda dose, ocorreu resposta em termos de IgA sérica para RV em 54,7 a 74,4 por cento dos vacinados. Não houve interferência na imunogenicidade das vacinas de rotina. A eficácia da vacina contra qualquer gastroenterite por rotavírus (GERV) foi de 63,5 por cento (IC95 por cento 20,8-84,4) para a maior concentração (10(5,8) UFF). A eficácia foi de 81,5 por cento (IC95 por cento 44,5-95,4) contra GERV grave. Em sua maior concentração (10(5,8) UFF), a RIX4414 conferiu uma proteção de 79,8 por cento (IC95 por cento 26,4-96,3) contra GERV grave causada pela amostra G9. CONCLUSÕES: A RIX4414 foi altamente imunogênica com baixa reatogenicidade, e não interferiu na resposta sérica à difteria, tétano, coqueluche, hepatite B e antígenos Hib. Duas doses da RIX4414 conferiram proteção significativa contra a GE grave causada pelo RV.
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 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 > 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 percent of vaccinees. No interference was seen in the immunogenicity of routine vaccines. Vaccine efficacy against any rotavirus gastroenteritis (RVGE) was 63.5 percent (95 percentCI 20.8-84.4) for the highest concentration (10(5.8) FFU). Efficacy was 81.5 percent (95 percentCI 44.5-95.4) against severe RVGE. At its highest concentration (10(5.8) FFU), RIX4414 provided 79.8 percent (95 percentCI 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.
Subject(s)
Humans , Infant , Antibodies, Viral/blood , Gastroenteritis/prevention & control , Rotavirus Infections/prevention & control , Vaccines, Attenuated/administration & dosage , Brazil , Double-Blind Method , Gastroenteritis/virology , Mexico , Rotavirus/immunology , Severity of Illness Index , Venezuela , Vaccines, Attenuated/adverse effects , Vaccines, Attenuated/immunologyABSTRACT
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 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. 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 (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. CONCLUSIONS: 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.