1. I've been thinking about the variables of #COVID19 risk, and how we move beyond the simplistic view of mortality vs survival rates. I've put together a list of things I think we should consider when deciding how to respond to the pandemic.

2. I know people who've experienced diabetes, cardiac, neurological, thyroid and other complications following infection by #SARSCoV2

We need to know what proportion of COVID-19 infections result in complications.

3. We need to understand the severity of these complications.

4. How long will these complications last? Will they resolve? Or will they last many years? Some SARS-CoV-1 patients suffered long-term complications, but should we expect this to be the case with SARS-CoV-2?

5. #LongCovid might be considered a complication of infection, but I think it's worth highlighting separately because it seems to be quite common and is persistent, which sets it apart from the intermitent or one off complications some people are experiencing.

6. We need to know the prevelance of Long Covid. I've seen estimates suggesting between 5% - 20% of those infected by SARS-CoV-2 will develop Long Covid.

What's the duration of Long Covid?

7. We need to know whether SARS-CoV-2 exhibits any seasonality. There's evidence to suggest it thrives at low temperature, but until we've experienced winter, we can't say for certain.

8. We need to understand the median duration of protective immunity? How long will most people be protected against another #SARS_CoV_2 infection?

9. Related but not the same is the median interval of reinfection. Even if infection doesn't elicit long-term protective immunity, social distancing or other measures can protect us against reinfection. Local policies will influence this figure.

10. Documented cases of reinfection in the US and Ecuador suggest a more severe second infection, which might point to ADE. We need to know whether this is the case and how common it is.

11. If it is happening, we need to know the role it plays in increasing the severity of second infection.

12. We need to understand what #COVID__19 infection does to life expectancy. Complications, T-Cell depletion, repeat infections, long-term illness might all play a role.

13. And alongside our understanding of the impact on life expectancy, we need to assess how #COVID19 might affect our healthy life years.

14. Once we have evidence and data for these different parameters, we can properly assess the risk (and cost) of #COVID19

The best case, low impact picture would look something like this.

15. The high impact picture would look something like this.

16. Until we can quantify each of these variables, the true risks (and impact & cost) of #COVID19 cannot be known.

Governments that try to downplay risk need to be honest that in the absence of evidence, policy is being guided by estimates and models.

17. In some cases government policy directly contravenes the estimates and models, and is based on little more than short-term thinking, political expediency or guesswork.

18. If these estimates or guesses are wrong, governments could be underestimating the individual and socioeconomic costs of allowing #COVID19 to spread.

With more data, we might find a #ZeroCovid policy is better & cheaper in the long run.