Drug makers must instead show "robust evidence" the tweaked shot results in an immune response, says the Medicines and Healthcare products Regulatory Agency (MHRA), per new guidance from the ACCESS Consortium, developed in partnership with regulators in Canada, Switzerland and elsewhere.
"Researchers are now better able to measure protection by looking at antibodies in the blood following vaccination, reducing the need to wait and see whether or not people in a trial become infected with the disease," reads a statement from MHRA posted Thursday. "This would significantly reduce the length of time taken for the modified vaccine to be ready for use."
Aside from efficacy data, sponsors must demonstrate the modified product is safe and up to quality standards. Data from the original trials backing emergency authorizations and ongoing studies in the real-world rollout could further support regulators’ decisions, the agency said.
MHRA said a similar approach is used to clear annual flu vaccines modified amid changing strains.
Dr. Christian Schneider, chief scientific officer at MHRA, said the goal is to get effective vaccines into arms as quickly as possible without compromising on safety.
"The public should be confident that no vaccine would be approved unless the expected high standards of safety, quality and effectiveness are met," he added.