So if there were no hospitalizations but protection against severe disease was 85%, does that mean 15% of people got severe disease but didn't go to the hospital? Maybe I'm not understanding the numbers correctly but I would think severe disease would often require hospitalization, especially for older folks, right?

I think what it means is that those 15% got sick but even in them the infection never reached the point where they had to go to the hospital. So they probably got what amounted to a pretty severe cold that would knock you out of work or normally activity for some time but not bad even to go to the hospital. Again, I'm no expert, but every micro and immunology class I ever took tells me that is a win.

In effect even when you get sick it severely lessens the severity of it.

Yea so maybe the question is what constitutes "severe" disease. I guess I would have assumed that a case that resolves at home without hospital intervention isn't severe.
Is there a standard for mild, moderate, and severe in this context?

Didn't mean to derail, but that piece of detail made me curious.

FlyFisher09 said:

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Yea so maybe the question is what constitutes "severe" disease. I guess I would have assumed that a case that resolves at home without hospital intervention isn't severe.
Is there a standard for mild, moderate, and severe in this context?

Didn't mean to derail, but that piece of detail made me curious.

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https://www.jnj.com/coronavirus/covid-19-phase-3-study-clinical-protocol#page58

All the definitions from all the trials are available online. They don't all have the same endpoints or use the same definitions, which is one reason why you can't compare them. The other is that they all had different patient populations.

The key though is what was posted on the previous page. No one who's gotten any of the vaccines in the trials was hospitalized or died.

I always thought part of the issue with the flu vaccine was guessing which strains to use any given season. They do statistical analysis and make an educated guess which strains will be circulating any given year, if they guess right it is effective if not then not quite as effective. Seems I remember a prof saying that but It has been a while (dating myself).

Correct. They make a best guess based on winter cases in Australia and China.

Yes, they do it twice a year, the northern hemisphere strains are chosen for the next year in February. I don't know, but do hope that the human RNA vaccines for covid will lead to similar increased flexibility/production ability long term for more efficacious flu vaccines.

https://www.cdc.gov/flu/prevent/vaccine-selection.htm

Quote:

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The seasonal influenza (flu) vaccine is designed to protect against the three or four influenza viruses that research indicates are most likely to spread and cause illness among people during the upcoming flu season. Flu viruses are constantly changing, so the vaccine composition is reviewed each year and updated as needed based on which influenza viruses are making people sick, the extent to which those viruses are spreading, and how well the previous season's vaccine protects against those viruses.
More than 100 national influenza centers in over 100 countries conduct year-round surveillance for influenza. This involves receiving and testing thousands of influenza virus samples from patients. The laboratories send representative viruses to five World Health Organization (WHO) Collaborating Centers for Reference and Research on Influenza, which are located in the following places:

• Atlanta, Georgia, USA (Centers for Disease Control and Prevention, CDC)
• London, United Kingdom (The Francis Crick Institute)
• Melbourne, Australia (Victoria Infectious Diseases Reference Laboratory)
• Tokyo, Japan (National Institute for Infectious Diseases)
• Beijing, China (National Institute for Viral Disease Control and Prevention)

Twice a year, the World Health Organization (WHO) organizes a consultation with the Directors of the six WHO Collaborating Centers, Essential Regulatory Laboratories and representatives of key national laboratories and academies. They review the results of surveillance, laboratory, and clinical studies, and the availability of vaccine viruses and make recommendations on the composition of the influenza vaccine.

These meetings take place in February for selection of the upcoming Northern Hemisphere's seasonal influenza vaccine and in September for the Southern Hemisphere's vaccine. The WHO recommends specific vaccine viruses for inclusion in influenza vaccines, but then each country makes their own decision about which viruses should be included in influenza vaccines licensed in their country.

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