Verification of Attenuated Biosafety Level 3 (BSL-3) Pathogens Policy

The purpose of this policy is to set forth the procedures for verification of attenuated BSL-3 pathogens before they may be safely handled at the lower biosafety level (BSL) designated for the attenuated pathogen.

This policy applies to all individuals engaged in research at or under the auspices of Boston University (BU) and covers all attenuated pathogens that meet all of the following criteria:

1. The attenuated agent is derived from a known and virulent pathogen that requires BSL-3 containment;
2. Attenuation results in decreased virulence of the pathogen; and
3. Attenuation results in a reduction in the BSL containment in which the attenuated pathogen can be handled compared with the BSL required for the safe handling of the non-attenuated counterpart.

This policy does not apply to BSL-3 agents that have been inactivated by a process that meets established and accepted scientific and safety standards approved by the Institutional Biosafety Committee (IBC). The requirements for working with inactivated BSL-3 pathogens are covered in the Inactivated Biological Sample Use policy.

Food and Drug Administration (FDA) approved vaccines that contain attenuated agents derived from pathogens may be excluded from this policy if the formulated vaccines are obtained directly from the vaccine manufacturer. Requests for use of such vaccines and the manufacturer’s documentation must be submitted as a new IBC protocol or an amendment to an approved IBC protocol. The IBC, in consultation with Environmental Health and Safety (EHS), will determine whether exclusion from the BU policy is allowable.

Attenuation of any BSL-3 pathogen must be verified before it may be handled at the lower BSL designated for the attenuated agent. Verification of attenuation must be performed at the BSL designated for the virulent wild-type strain. A verification plan with detailed methods for the particular attenuated pathogen must be approved by the IBC before shipments of the attenuated BSL-3 pathogen can be received at BU and before work with the attenuated agent may be initiated. Confirmation of the attenuation must be submitted to the IBC for final approval before the attenuated agent can be moved out of the BSL-3 laboratory into lower containment.

If the identity of an attenuated agent cannot be verified, it must be handled at the BSL designated for the non-attenuated wild-type pathogen.

The Principal Investigator (PI) must have an IBC-approved protocol in place prior to submitting a verification plan for an attenuated BSL-3 agent.

The PI must submit a verification of attenuation plan to the IBC and the IBC must grant the verification plan full approval before shipments of attenuated BSL-3 materials can be received and before work with the attenuated agent may begin. EHS must be notified of all incoming shipments. Upon receipt, the package(s) must be transferred to the BSL-3 laboratory for verification of attenuation.

Verification must be performed using an approved method to distinguish between the attenuated and wild type strain (e.g., polymerase chain reaction “PCR” or reverse transcription “RT-PCR”). The verification plan may also include an individualized verification protocol to experimentally distinguish the non-attenuated wild-type pathogen and the attenuated pathogen. A good verification plan will include multiple approaches that provide consistent data to support a conclusion that the strain is attenuated.

Each verification plan must include samples from both the inactivated wild-type and the attenuated strain such as genomic DNA or RNA samples, or plasmid DNA containing the original and attenuated virulence factor(s). These samples may be obtained from other investigators. Verification must be conducted on the received stock which is designated the Master Stock. Whenever possible, verification should be carried out on an individual clone (e.g., single colony or plaque) that has been isolated from the Master Stock. Only material from the verified colony/plaque can be studied at the lower BSL.

Confirmation of the attenuation must be submitted to the IBC for final approval before the pathogen can be moved out of the BSL-3 laboratory into lower containment.

If attenuation cannot be confirmed, the pathogen must be handled at BSL-3.