Will you cruise without a COVID vaccine?

[TeeRick]

16 hours ago, markeb said:

Data?

 

Both positive and negative predictive value are questioned in the interim guidance today. There is no such thing as reliability  or accuracy in a diagnostic test. Sensitivity, specificity, positive predictive value, and negative predictive value matter. If the prevalence of SARS-CoV-2 (infection rate, not actual disease) is higher than originally believed, then the positive predictive value will be higher. Ironically, you need a good test for prevalence to make that estimate,without cross-reactivity to other common coronaviruses. The rapid LFI's that everyone is using are probably the most suspect. High complexity testing in a laboratory that actually gives a quantitative titer would have much more meaning.

 

I think that most people in government would like to believe that a significant percentage of the population have been exposed with minimal disease and are immune. Frankly, absent a second wave, or significant testing, probably in an animal model that hasn't been fully developed, we won't know that. And if the second wave varies significantly from the first wave, which now has to be questioned, it may not matter.

 

 

Here is the FDA's updated policy on Antibody tests.  Antibody test developers will be expected to submit official requests for an Emergency Use Authorization—along with their validation results—to the FDA within 10 days.

https://www.fda.gov/news-events/fda-voices/insight-fdas-revised-policy-antibody-tests-prioritizing-access-and-accuracy

[TeeRick]

18 hours ago, Ride-The-Waves said:

Los Alamos National Lab in conjunction with scientists at Duke and Sheffield Universities have identified 14 strains of coronavirus.  The deadliest being the strain that hit New York coming over from Italy, and which is dealer than the originally Wuhan identified strain.

 

https://www.msn.com/en-us/news/health-news/a-mutant-coronavirus-has-emerged-even-more-contagious-than-the-original-study-says/ar-BB13CHNP

 

This upends the idea that the virus is stable and doesn't mutate.  Designing and testing a viable vaccine becomes problematic if COVID-19 is unstable.  Might was well call it "Andromeda Strain."

Actually this is not at all a surprise but very much expected.  SARS-CoV-2 has an RNA genome and like other RNA viruses is highly prone to mutation since it cannot "proofread" itself when making copies.  So RNA viruses by definition are not "stable". But it is still possible to make a vaccine.  Difficult yes but still possible.  There will be pieces of the virus that are absolutely required for entry into human cells and replication.  These will likely be highly conserved (hopefully!) on virulent strains.  Many many other mutant strains will arise but will not be virulent or as virulent.  So the successful vaccine developers will target the highly conserved antigenic regions once they are discovered.