Science’s COVID-19 reporting is supported by the Pulitzer Center and the Heising-Simons Foundation.
The backers of Australia’s homegrown COVID-19 vaccine candidate today announced a halt to its further development, after some of the first people to receive the vaccine in a safety trial generated antibodies to an unintended target, the AIDS virus. A small fragment of an HIV protein is a component of the vaccine used to add stability to the intended antibody target, the spike protein of the pandemic coronavirus SARS-CoV-2.
Although the added component didn’t represent an actual infection with HIV, the vaccine developers and the Australian government concluded a widespread rollout of the candidate would interfere with HIV diagnostic tests and decided not to proceed to larger clinical trials that would have measured its protection against COVID-19. Given the strong efficacy shown by several recent COVID-19 vaccines, it’s likely that other candidates still in development will now have a higher bar to clear to move forward.