Viability of live-attenuated vaccine strains in a pharmaceutical dump

Abstract number: P1590

Bianchi S., Canuti M., Zappa A., Koncan R., Cornaglia G., Tanzi E., Tridente G., Amendola A.

Objectives: To assess the viability of discarded and buried vaccine strains, we examined vaccines that had been buried for >20 years in the 12,000m2 waste dump of the bankrupted Istituto Sieroterapico Milanese (ISM) in Milan, Italy. This dump area was recently reclaimed after nearly a decade of abandonment. Some recovered material, including vaccines against human and animal diseases such as rabies, poliomyelitis, anthrax, Newcastle Disease (ND) and Canine Distemper (CD), were recovered in hermetically sealed vials, so their contents might have been totally or partially preserved.

Methods: We selected and analysed two lyophilised live attenuated CD Virus (CDV) vaccines, recovered and unearthed in the dump.

An amplification of a specific 550bp fragment of CDV NP gene was performed by nested RT-PCR. The PCR-positive specimens were then submitted to the viability tests through the inoculation of the resuspended vaccine on a confluent monolayer of permissive cell cultures (Vero, African green monkey kidney) and the detection of the specific cytopathic effect. As positive control, we used a vaccine against the CDV currently in use, Caniffa-CHL, (Merial Italy S.p.a., Milan, titre geqslant R: gt-or-equal, slanted103 CCID_50).

Results: CDV lyophilised vaccine samples resulted positive to the PCR-analysis, attesting the competence and integrity of the viral genome in the vials.

Three days after the inoculation of the sample on Vero cells we observed the specific cytopathic effect (lysis plaque formation).

Conclusions: This result confirmed that CDVs recovered in the dump were endowed with viability, thus showing they retained their replicative ability, as previously reported for ND Virus vaccine strains (Amendola et al, Emerg Infect Dis. 2007). The discovery of the maintenance of the replication activities of lyophilised vaccine strains after 30 years of burial is relevant because it emphasises that such preparation may preserve viable strains. This event seems occur independently of the virus species, and therefore it is also possible that viruses that can cause hazard to humans (as poxvirus or poliovirus) may persist for years and be dangerous at the moment of manipulation while reclaiming activities take place. Altogether, these evidences strongly underline the need of guidelines for the disposal of such particular products, such as vaccines and their by-products, and the lack of studies aimed at evaluating the environmental infection risk from the uncontrolled burial of industrial bio-material.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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