3 ms·

A possible mechanism I have seen mentioned is Antibody Dependent Enhancement: https://en.wikipedia.org/wiki/Antibody-dependent_enhancement https://en.wikipedia

A possible mechanism I have seen mentioned is Antibody Dependent Enhancement: https://en.wikipedia.org/wiki/Antibody-dependent_enhancement https://en.wikipedia.org/wiki/Antibody-dependent_enhancement I am not a biologist and have no opinion on the matter, I have just seen it mentioned online.

belter 5y ago
Interesting. It seems that this was actually a concern and considered during initial development of COVID vaccines. It seems it was considered not likely to happen but there is this interesting part here from 2019 that caught my attention: "Consensus summary report for CEPI/BC March 12–13, 2020 meeting: Assessment of risk of disease enhancement with COVID-19 vaccines" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7247514/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7247514/ "A syndrome of “disease enhancement” has been reported in the past for a few viral vaccines where those immunized suffered increased severity or death when they later encountered the virus or were found to have an increased frequency of infection. Animal models allowed scientists to determine the underlying mechanism for the former in the case of Respiratory syncytial virus (RSV) vaccine and have been utilized to design and screen new RSV vaccine candidates. Because some Middle East respiratory syndrome (MERS) and SARS-CoV-1 vaccines have shown evidence of disease enhancement in some animal models, this is a particular concern for SARS-CoV-2 vaccines. To address this challenge, the Coalition for Epidemic Preparedness Innovations (CEPI) and the Brighton Collaboration (BC) Safety Platform for Emergency vACcines (SPEAC) convened a scientific working meeting on March 12 and 13, 2020 of experts in the field of vaccine immunology and coronaviruses to consider what vaccine designs could reduce safety concerns and how animal models and immunological assessments in early clinical trials can help to assess the risk. This report summarizes the evidence presented and provides considerations for safety assessment of COVID-19 vaccine candidates in accelerated vaccine development."
- belter 5y ago
  Hopefully somebody will be able to comment further. In the meanwhile...I found this a good quality overview of the issue. Reference includes video and transcript for quicker read. The TL;DR is that is considered unlikely for reasons explained. ( but not completely impossible ) "Do COVID-19 Vaccines Cause Antibody-dependent Enhancement (ADE)?" https://www.chop.edu/centers-programs/vaccine-education-center/video/do-covid-19-vaccines-cause-antibody-dependent-enhancement https://www.chop.edu/centers-programs/vaccine-education-cent...
polotics 5y ago
Can someone who knows more than me comment on my impression that the likelihood of ADE is much reduced with the very narrow (ie. spike-only) targeting of mRNA vaccines?
throwawayboise 5y ago
ADE can also happen with exposure to a virus itself, such as happens with Dengue fever. It's not something strictly limited to vaccines.
- belter 5y ago
  Correct. That is also mentioned in the reference with video I posted.
- higherup 5y ago
  >It's not something strictly limited to vaccines. I think it is the case if the vaccine does not provide sterilising immunity..

belter 5y ago

Interesting. It seems that this was actually a concern and considered during initial development of COVID vaccines. It seems it was considered not likely to happen but there is this interesting part here from 2019 that caught my attention: "Consensus summary report for CEPI/BC March 12–13, 2020 meeting: Assessment of risk of disease enhancement with COVID-19 vaccines" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7247514/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7247514/ "A syndrome of “disease enhancement” has been reported in the past for a few viral vaccines where those immunized suffered increased severity or death when they later encountered the virus or were found to have an increased frequency of infection. Animal models allowed scientists to determine the underlying mechanism for the former in the case of Respiratory syncytial virus (RSV) vaccine and have been utilized to design and screen new RSV vaccine candidates. Because some Middle East respiratory syndrome (MERS) and SARS-CoV-1 vaccines have shown evidence of disease enhancement in some animal models, this is a particular concern for SARS-CoV-2 vaccines. To address this challenge, the Coalition for Epidemic Preparedness Innovations (CEPI) and the Brighton Collaboration (BC) Safety Platform for Emergency vACcines (SPEAC) convened a scientific working meeting on March 12 and 13, 2020 of experts in the field of vaccine immunology and coronaviruses to consider what vaccine designs could reduce safety concerns and how animal models and immunological assessments in early clinical trials can help to assess the risk. This report summarizes the evidence presented and provides considerations for safety assessment of COVID-19 vaccine candidates in accelerated vaccine development."

belter 5y ago
Hopefully somebody will be able to comment further. In the meanwhile...I found this a good quality overview of the issue. Reference includes video and transcript for quicker read. The TL;DR is that is considered unlikely for reasons explained. ( but not completely impossible ) "Do COVID-19 Vaccines Cause Antibody-dependent Enhancement (ADE)?" https://www.chop.edu/centers-programs/vaccine-education-center/video/do-covid-19-vaccines-cause-antibody-dependent-enhancement https://www.chop.edu/centers-programs/vaccine-education-cent...

polotics 5y ago

Can someone who knows more than me comment on my impression that the likelihood of ADE is much reduced with the very narrow (ie. spike-only) targeting of mRNA vaccines?

throwawayboise 5y ago

ADE can also happen with exposure to a virus itself, such as happens with Dengue fever. It's not something strictly limited to vaccines.

belter 5y ago
Correct. That is also mentioned in the reference with video I posted.
higherup 5y ago
>It's not something strictly limited to vaccines. I think it is the case if the vaccine does not provide sterilising immunity..