PubMed Health⌕ Search

Biomedical subjects

T Ruuska

Publications and source records attributed to T Ruuska.

42 records · Page 3Linked to original sources
PubMed1987

Clinical trials of rotavirus vaccines.

The clinical efficacy of candidate rotavirus vaccines has been tested in Tampere, Finland, over four winter and spring rotavirus epidemic seasons in 1983-1986. Testing against natural challenge has demonstrated that heterologous oral rotavirus vaccines induce cross-protection to human rotavirus diarrhoea. The trials have also given insight into mechanisms of protection in human rotavirus diarrhoea. After the oral vaccination of infants aged six to 12 months the highly attenuated bovine rotavirus strain RIT 4237, titre 10(8) per dose, probably 'takes' in most vaccinees, producing a symptomless intestinal infection with a low virus excretion rate and an antibody response in over 80% of the initially seronegative subjects. Upon natural challenge such vaccination gives no protection against human rotavirus infection but gives 50-60% protection against any clinically detectable rotavirus-associated illness and 80-90% protection against severe rotavirus diarrhoea, regardless of the infecting human rotavirus serotype. The less attenuated rhesus monkey rotavirus RRV-1, titre 10(5)-10(6) per dose, is more infectious in humans, and virus multiplication in the intestine results in excretion of vaccine virus in the stools and some clinical symptoms, mainly fever, 3-4 days after vaccination. The degree of protection against human rotavirus diarrhoea appears similar to that induced by bovine rotavirus vaccine.

Antibodies, Viral↗
PubMed1987

Neonatal rotavirus vaccination with RIT 4237 bovine rotavirus vaccine: a preliminary report.

We vaccinated 244 newborn infants orally with RIT 4237 bovine rotavirus vaccine or placebo and followed them serologically and clinically for 16 months. Initially 39 of the 119 (33%) vaccine recipients compared with 1 of the 120 placebo recipients seroconverted by enzyme-linked immunosorbent assay-immunoglobulin M. After the first winter rotavirus season, at 7 months of age 55% of the vaccinated infants and 37% of the unvaccinated infants were rotavirus-seropositive by enzyme-linked immunosorbent assay-immunoglobulin G (P less than 0.01, chi square test). At 12 months of age, after a low rotavirus prevalence season, 34% of the vaccinated children and 23% of the unvaccinated children remained seropositive. There were 14 confirmed episodes of rotavirus gastroenteritis in the vaccine group and 10 episodes in the placebo group during the first 16 months. However, only 1 of the episodes in the vaccine group was severe, 4 were moderately severe and 9 were mild, whereas 7 episodes in the placebo group were severe and 3 were moderately severe (P less than 0.001 between groups, Fisher's exact test). There was no clear correlation between vaccine-induced clinical protection and initial serologic response (enzyme-linked immunosorbent assay-immunoglobulin M) to vaccination, but during follow-up severe rotavirus gastroenteritis was more likely to occur in children with no serum rotavirus immunoglobulin G antibody at the time of infection. We conclude at the present stage that neonatal rotavirus vaccination with RIT 4237 vaccine gives no protection against rotavirus infection but appears to modify the severity of gastroenteritis.

Clinical Trials as Topic↗
PubMed1986

Oral rotavirus vaccination in breast- and bottle-fed infants aged 6 to 12 months.

Oral bovine rotavirus vaccine RIT 4237 was tested at two dose levels in 217 children between 6 and 12 months of age who received either breast milk or bottle milk (cow's milk or infant formula) before vaccination. Of the children 65% were initially seronegative for rotavirus ELISA IgG and IgM antibody. The full vaccine dose (10(8.3) 50% tissue culture infective doses, TCID50) induced seroconversion rates 81% and 86% and booster response rates 69% and 64% in breast and bottle-fed children, respectively. There was no difference in the vaccine response of infants receiving cow's milk or infant formula either. It is concluded that the RIT 4237 rotavirus vaccine at the dose level 10(8.3) TCID50 gives a satisfactory response in both breast- and bottle-fed children in this age group, but multiple vaccinations may be needed for maximal efficacy.

Administration, Oral↗
PubMedDate not supplied

Dose-response study of RIT 4237 oral rotavirus vaccine in breast-fed and formula-fed infants.

The RIT 4237 live attenuated bovine rotavirus vaccine was given orally at three dose levels to 75 breast-fed, 40 formula-fed and 24 fasting infants ages 4 to 6 months. Vaccine of 10(8.3) (50% tissue culture-infective doses) (TCID50) per dose gave a neutralizing antibody response in 14 of 14 (100%) formula-fed, in 18 of 26 (69%) breast-fed and in 5 of 8 (63%) fasting infants, or an overall response rate of 77% (37 of 48). The overall response rate to a vaccine of 10(7.2) TCID50 per dose was 61% (33 of 49), or slightly but not significantly lower than that at the higher dose level. On the other hand a vaccine of 10(6.3) TCID50 per dose gave a significantly (P less than 0.01) lower composite response rate of 33% (14 of 42). The overall serologic response rate to the vaccine at the two higher doses was somewhat better (24 of 28, 86%) in formula-fed infants than in breast-fed infants (37 of 52, 71%). However, the response rate of the breast-fed infants can also be considered satisfactory. Thus the current recommendation for use of the RIT 4237 vaccine would be administration of a dose of at least 10(8) TCID50 after feeding with either formula or breast milk.

Administration, Oral↗
PubMedDate not supplied

Mutans streptococcal serotypes in children with gastroesophageal reflux disease.

It has been suggested that vomiting acid gastric contents in bulimia might favor oral growth of Streptococcus sobrinus. We studied the colonization of Streptococcus sobrinus (serotypes g and d) and Streptococcus mutans (serotypes c, e and f) in sixteen children, ages five to fifteen years, who had suffered for four to eleven years from gastroesophageal reflux, another condition with recurrent acid regurgitation. Our aim was to find out if the prevalence of Streptococcus sobrinus would be higher also in this patient group. Mutants streptococci were detected in twelve out of sixteen (75 percent) study patients of the saliva samples cultured on MSB agar. For the Mutans streptococci positive children healthy controls were matched by salivary levels of mutans streptococci and age as closely as possible. From each child three to six isolates representing both Streptococcus mutans and Streptococcus sobrinus (n = 103) were serotyped by immunodiffusion method. The distribution of serotypes in the study/control group was: c: 7/10; e: 4/2; f: 0/1; g:3/2; d:0/0. One strain in the study group remained untypable. All patients infected with Streptococcus sobrinus were also infected with Streptococcus mutans. Our results indicate the great similarity in the distribution of ms serotypes in the gastroesophageal reflux children and their healthy controls. The data do not suggest that the acid regurgitation would have an influence on the prevalence of Streptococcus sobrinus.

Adolescent↗