Sequential and combined immunization of infants with oral and inactivated poliovirus vaccines: controlled study of reactogenicty and immunogenicity

We conducted a clinical trial to assess an immunization schedule combining oral [OPV] and inactivated poliovirus vaccines [IPV] in infants residing four rural communities in Abu Homos district, Beheira Governorate, Egypt. Infants in group "A" received OPV during their first month and at 2, 4 and 6 months of age. Infants in group "B" received OPV during their first month and 2 months followed by both OPV and IPV at 4 and 6 months of age [combined-schedule group]. The OPV vaccine is manufactured by Egyptian Organization for Biological Products and Vaccines [VACSERA] in Egypt while the IPV is a product of Pasteur Merieux [France]. Adverse events were monitored for three days after each dose. Blood was collected before immunization and 4 weeks after each dose to assess vaccine specific serological response. A total of 163 infants received 3 correct doses, had inter-dose intervals within the allowable range and provided 4 samples of blood, were included in the per protocol analysis [85 in group "A" and 78 in group "B"]. There was no statistically significant intergroup difference in the percentage of subject reporting the primary safety endpoint [diarrhea, vomiting, fever, irritability or local reactions at the site of IPV injection] during the 3-day after each dose. There was a statistically significant greater reporting of ill feeling in group "A" after dose I and II [p<0.001] compared to group "B". All infants in the two groups acquired protective immunity, determined as possession of neutralizing antibodies at titre > 1:8 after completing vaccination. However, the geometric mean titres to each poliovirus type were significantly higher in vaccinees in group B [p<0.001]. Seroconversion rates [> 4-fold rise in titre] to each poliovirus type were high in the two treatment groups after the last dose. Difference in seroconversion rates between the two treatment groups was not statistically significant. These finding demonstrated that the combined use of OPV and IPV didn't improve immunogenicity over the use of OPV alone. The study protocol and subject-informed consent were approved by independent Ethics Committee of the participating institution [VACSERA] and the National Organization for Drug Control and Research [Egyptian National Regulatory Authority]. The study was conducted according to the Declaration of Helsinki and the International Conference on Harmonization for Good Clinical Practice. Written informed consent was obtained from all subjects prior to conducting study-related procedures

Administration of tetanus toxoid [TT] to pregnant women versus tetanus and reduced diphtheria [Td]: a randomized controlled

We conducted a clinical trial to compare the immunogenicity, reactogenicity and efficacy of Tetanus Toxoid [TT] and the combined Tetanus and reduced Diphtheria [Td] in pregnant women residing four rural communities in Egypt. The study has been designed as a randomized controlled trial. Pregnant women in each of the four villages received either TT or Td randomly. Both TT and Td vaccines are manufactured by the Egyptian Company for Biological Products and Vaccines [VACSERA] in Egypt. A total of 131 pregnant women were enrolled at the time of their antenatal care visit [at the beginning of their fifth gestational month] to one of four health units in Abu Homos district, Beheira Governorate, Egypt. Previously un-immunized women received at random 2 doses of TT or Td eight weeks apart during their pregnancy. Active outpatient follow-up for adverse events was done on the third day after each dose. Local [pain, redness and swelling] or general [fever, malaise and headache or body aches] reactions during the 3-day post-dosing interval served as the primary safety end point. Blood was collected 3 times from each subject to detect antibody level against tetanus and diphtheria by ELISA. The first sample was collected immediately before the first dose, the second before the 2[nd] dose and the third sample one week after delivery. Active surveillance home visits to all study participants were conducted twice. The first home visit was during the first week after delivery and the second one month after labor to report the health status of the mother and the baby. A total of 122 pregnant women received 2 correct doses had inter-dose intervals within the allowable range and provided 3 samples of blood, were included in per protocol analysis [62 in the TT group and 60 in the Td group]. There was no statistically significant inter group difference in the percentage of subject reporting the primary safety endpoint [fever, malaise, body ache, headache] or local reactions at the site of injection as redness and swelling, during the 3-day after each dose. There was a statistically significant greater reporting of pain at injection site in the Td group after dose I and II compared to the TT group. Home visits revealed normal mothers and babies on clinical examination in both groups. However, more babies in the TT group suffered from physiological jaundice. All women in the two groups acquired protective immunity for tetanus, determined as possession of neutralizing antibodies at titre>0.10 IU/ml after completing vaccination. However, the geometric mean titres of tetanus post dose I and II were significantly higher in vaccinees in the TT group [P<0.001]. For diphtheria, post vaccination seroprotection [titre>0.10 lU/ml] was significantly higher in the group received Id than the TT group. Geometric mean Titres of diphtheria post dose II were significantly higher in vaccinees in the Td compared to the other group [P<0.0001]. These finding demonstrared that the use o Td vaccine improves immunogenicity for both tetanus and diphtheria over the use of 'IT vaccine alone and may be recommended to replace TT in immunization of pregnant women.