1) With the release of Novavax data we are starting to get a good handle on how the level of immunity correlates with vaccine efficacy. So can use this to predict the efficacy of vaccines on the horizon, based on current data? Let’s give it a go! A little. #CovidVaccine

2) A few things to note:
- This is a very crude analysis based on a very small number of data points
- Did I mention this was a very crude analysis?
- Assumption is level of neutralizing antibodies (NAbs) is indicator of protective efficacy (but likely more complex than this)

3) The analysis:
- Compare level NAbs in human trials and with that of COVID patients (from same study)
- Results in a ratio comparing relative fold difference between vaccinees and COVID samples
Can then plot against efficacy for the 3 vaccines with published data. Get this:

4) And if we add Novavax, correlates pretty well. Keep in mind Novavax had to deal with the B.1.1.7 variant, so if compares nicely with Pfizer and Moderna if you only look at protection against non-B.1.1.7.

5) so can we look into the future and predict J&J results? We can try! I actually think the single dose will do better than predicted below, but let's wait and see...

6) Now what about using the change in NAbs against the variants and trying to predict how well the vaccines might work? If we use the study from the Ho lab as a guide ( http://doi.org/10.1101/2021.01.25.428137), we get this:

7) So about 75% protection for Pfizer vaccine against B.1.1.7 and ~60% against B.1.351 (SA variant). This sort of matches the Novavax data against B.1.351 of 50%.. https://ir.novavax.com/news-releases/news-release-details/novavax-covid-19-vaccine-demonstrates-893-efficacy-uk-phase-3

8) Probably not that simple however. Looking at data from Ho study there is a subset of vaccinees (~50%) with near background level of NAbs against B.1.351 variant, most apparent in those given Pfizer vaccine. Assumption is when you drop into this group, you may lose protection

9) so the overall conclusion? An obvious one, the stronger the immunity the better!! However it may be that variants could induce complete immune escape in some individuals, and thus next-gen vaccine will be needed for these variants. Obviously we need more data to confirm...

10) and apologies to AstraZeneca for spelling error, too late to change!!