Improved manometric setup for the accurate determination of supercritical carbon dioxide sorption.

An improved version of the manometric apparatus and its procedures for measuring excess sorption of supercritical carbon dioxide are presented in detail with a comprehensive error analysis. An improved manometric apparatus is necessary for accurate excess sorption measurements with supercritical carbon dioxide due to the difficulties associated with the high sensitivity of density for pressure and temperature changes. The accuracy of the apparatus is validated by a duplicate measurement and a comparison with literature data.

Potency measurement of pertussis vaccines and consistency in production.

If one accepts the minimum requirement of 4 i.u. shd-1 for the potency of pertussis vaccine--and there is no convincing evidence to reject this--the usual MPT with 20 mice per dilution offers a sufficient guarantee that no vaccines with too low potency will be accepted, provided that the consistency in production has been sufficiently proven.

A two-dose schedule for immunization of infants using a more concentrated DPT-vaccine.

In a controlled field-trial in infants in the Philippines, a two-dose schedule with an interval of 6 months between injections using a concentrated adsorbed DPT-vaccine was evaluated. The serologic response against the three components in the vaccine was satisfactory, whereas the side-effects in the concentrated vaccine group did not differ from those observed in a control DPT group. After two injections, the coverage percentage with DPT-vaccine was shown to be higher than 70%.

Possible use of the oxygen uptake rate in the evaluation of BCG vaccines.

Two existing methods suitable for the determination of the oxygen uptake rate (OUR) in BCG suspensions (Warburg and Gilson Oxygraph) are described and compared. With the former method the oxygen uptake rates of the 10 samples of the BCG collaborative assay of the BCG Steering Committee of the International Association of Biological Standardization were determined. When the results are compared with those of colony count and skin reactivity from the collaborative assay, there is a better correlation between OUR and skin reactivity than between OUR and colony count.