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This is exactly why you wouldn’t need a challenge trial: lots of people are already regularly exposed to the virus. Immunize some of them and see if the infecti
by mattkrause 7y ago
This is exactly why you wouldn’t need a challenge trial: lots of people are already regularly exposed to the virus. Immunize some of them and see if the infection rate is lower in that group vs a control.
- claudeganon 7y agoExcept failed vaccines can induce a response that makes you more susceptible to the disease and with worse symptoms. It’s called antibody-dependent enhancement: https://pubmed.ncbi.nlm.nih.gov/12725690/ https://pubmed.ncbi.nlm.nih.gov/12725690/ Just about the last people you’d want to risk that kind of vaccine trial on are healthcare workers, who are already in short supply.
- mattkrause 7y agoI didn’t say healthcare workers. I said that there’s plenty of incidental exposure already: healthcare workers, yes, but also nearly everyone who’s leaving the home too. It is literally a pandemic! This point is actually made in the article itself: they want to get it done while and where there’s community transmission to avoid the ethical fraught ness of a challenge trial. For similar reasons, challenge trials also weren’t done for AIDS PrEP, since there were groups with enough lifestyle exposure to power a study.
- lbeltrame 7y agoSinovac (which is testing an attenuated vaccine) published some data on a preprint[1] claiming it does not cause ADE. [1] https://www.biorxiv.org/content/10.1101/2020.04.17.046375v1 https://www.biorxiv.org/content/10.1101/2020.04.17.046375v1