At NICVB, we’ve already been performing the potency test for wP vaccines, but not for aP ones yet. The updated current trend implies that injecting aP vaccines instead of wP ones can help lower the risk of adverse reactions in children. Thus, at present, the urgent demand is to study and practice the technical method of potency testing of aP vaccine which is responding to its increasing popularity.

Being supported by World Health Organization, at the middle of 1st quarter of 2017, NICVB assigned a technical staff from Quality Control of Bacterial Vaccine Department to take part in the training course at NIID, Japan on quality control of aP vaccine.

The procedure of quality control of aP vaccine requires the mice strain ICR or DDY 4-week aged, female with inexperienced immunity system. After injecting vaccine, mice are closely observed within 3 weeks. There are at least 16 mice assured in each concentration. Culturing strains is conducted before ongoing challenge 1 week. Injecting each mouse with 0.025µl challenge bacterial strain. It doesn’t take over 2 hours and a half from strain preparation to injection. Test is valid only if the procedure is properly followed, in other words, only if the factors and conditions are firmly assured and don’t affect the testing results at all. LD50 should be in the range of 50 – 400 bacteria each mouse, whereas required potency of vaccine must be ≥ 8 IU/mL and the lower limit of the 95% confidence interval of potency must achieve ≥ 4 IU/mL.

The train course finished successfully as NICVB’s trainee was updated the testing procedure and techniques. After considering actual conditions at NICVB, we find that the aP quality control testing could be carried out in Vietnam if our technicians are offered necessary materials and equipment.

Photo: Ms. Kim Xuyen, Quality Control of Bacterial Vaccine Department was performing the test