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# Historic Data Show Vaccine Approval Risks: Lurie
- URL: https://www.fdaweb.com/historic-data-show-vaccine-approval-risks-lurie/
- Published: 2020-09-17T12:00:00.000Z
- Updated: 2026-09-14T16:29:07.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5147669

Former FDA associate commissioner for public health strategy and analysis **Peter Lurie** says industry data showing that only 10% to 14% of compounds entering human testing in the last several decades were ultimately approved should be used to caution the public not to expect that all Covid-19 vaccines will be safe, effective, and approved. Writing in a *Washington Post* op-ed [column](https://www.washingtonpost.com/opinions/2020/09/15/nobody-wants-vaccine-trials-fail-they-just-might/?ref=fdaweb.com), Lurie, who now heads the Center for Science in the Public Interest, says the data show that compounds that make it to Phase 3 trials have about a 50% chance of being approved.

“In the midst of a pandemic,” Lurie writes, “it remains appropriate to prepare for the possibility that a vaccine will succeed by preparing plans to administer the product and ramping up production, as the administration has done. But what we shouldn’t be doing is ramping up public expectation that an effective vaccine is imminent. We will soon learn the outcome of these trials. In the meantime, let’s prepare members of the public for the possibility that they may have to continue the social distancing and mask-wearing that, when rigorously practiced, have been so effective in this pandemic.”

The column says that all assessments of when a vaccine might be available are based on an assumption that at least one of those currently in clinical trials will prove to be effective and safe. While Lurie says he hopes that’s the case, if the assumption is faulty there would be no way to estimate when a successful trial might be completed and a vaccine available.

He describes the three phases of vaccine clinical trials and discusses work he led at FDA at the end of the Obama administration to look at 22 case studies of products in which promising Phase 2 results were not confirmed by subsequent Phase 3 testing. Of the 22 case studies, Lurie reports, 14 had Phase 3 studies that failed to confirm product effectiveness hinted at in Phase 2, one identified a safety issue, and seven could not confirm either safety or effectiveness. Phase 3 studies for two products demonstrated that they caused a higher rate of the condition they were designed to prevent, he says.

Lurie says the case study most relevant to the coronavirus pandemic was a vaccine for herpes Type 2\. While two Phase 2 studies showed that patients developed antibody responses similar to those in patients who acquired herpes naturally, in the two Phase 3 studies for the vaccine the vaccinated groups acquired herpes at the same rate as the placebo groups, and the product was abandoned.

“The public discourse seems to assume that all or most of the Covid-19 products undergoing Phase 3 testing will work,” Lurie cautions. “But, if past is prologue, there is a chance that some or maybe even all will not prove effective and safe.”