Let& #39;s talk about #Herd_Immunity, given some recent interviews on the #COVID19SWEDEN strategy have talked about this being & #39;a result& #39;... is this achievable, sensible and acceptable?

1. #Immunity: Do people get long term #Immunity? We can& #39;t possibly know yet! But a study from China found that not all those who recovered from #COVID19 had high levels of antibodies... https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v1">https://www.medrxiv.org/content/1...

2. #Immunity: Looking to other coronaviruses, a study on #SARS patients found approx. 50% did not have SARS specific IgG (an antibody) 3 years after infection... and we don& #39;t tend to have long term immunity to the common cold either... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/">https://www.ncbi.nlm.nih.gov/pmc/artic...

3. Re-infection: are we seeing re-infections? In S. Korea, so far 111 people have tested positive following negative tests, leading to a hypothesis of "re-activation"... A LOT more data + research is needed! https://www.reuters.com/article/us-health-coronavirus-southkorea/south-korea-reports-recovered-coronavirus-patients-testing-positive-again-idUSKCN21S15X
https://www.reuters.com/article/u... href=" http://www.koreaherald.com/view.php?ud=20200412000213&np=3&mp=1
https://www.koreaherald.com/view.php... href=" https://www.medrxiv.org/content/10.1101/2020.03.26.20044222v1.full.pdf">https://www.medrxiv.org/content/1...

Over 110 people retest positive for coronavirus: authorities

The number of people who fully recovered from the new coronavirus and retest positive topped 110 in South Korea, health authorities said Sunday. According to the Korea Centers for Disease Control and...

https://www.reuters.com/article/us-health-coronavirus-southkorea/south-korea-reports-recovered-coronavirus-patients-testing-positive-again-idUSKCN21S15X

4. Long term morbidity: there are clinical reports that #COVID19 causes damage to heart, liver, and kidney... as well as lungs. We currently don& #39;t have data on the long term health impacts of the acute infection (or treatments). https://nymag.com/intelligencer/2020/04/more-bad-news-on-the-long-term-effects-of-the-coronavirus.html">https://nymag.com/intellige...

5. Numbers infected: the formula used to determine how many need to be vaccinated to reach #Herd_Immunity is (assuming 100% efficacy):

1 - 1/R0

R0 = 1.5 https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow"> 33%
R0 = 2 https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow"> 50%
R0 = 2.5 https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow">60%
R0 = 3 https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow"> 67%
R0 = 3.5 https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow"> 71%

https://www.ecdc.europa.eu/sites/default/files/documents/RRA-seventh-update-Outbreak-of-coronavirus-disease-COVID-19.pdf">https://www.ecdc.europa.eu/sites/def...

6. Lets take scenarios of R0 = 2 and 3.5. In #Sweden, this means 5.1 - 7.2 million infections.

Using IFRs of 0.1 - 1% means between 5100-72000 deaths. An IFR estimate from China was 0.66%, and unpublished from Germany of 0.37%

https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30243-7/fulltext">https://www.thelancet.com/journals/... https://www.nature.com/articles/d41591-020-00011-3">https://www.nature.com/articles/...

7. #Vaccine: There are currently 115 #COVID19 #Vaccine candidates, most still at early stages. However, 90% don& #39;t make it usually... so we cannot be sure a vaccine will happen, or when it would happen. https://www.nature.com/articles/d41573-020-00073-5">https://www.nature.com/articles/...

8. #Treatment: @WHO currently reports 137 studies for different #COVID19 therapeutics https://abs.twimg.com/emoji/v2/... draggable="false" alt="💊" title="Pill" aria-label="Emoji: Pill">. And some 960 clinical trials on-going.... I mean, that& #39;s impressive (but obvs same caution as https://abs.twimg.com/emoji/v2/... draggable="false" alt="⬆️" title="Upwards arrow" aria-label="Emoji: Upwards arrow">).
https://app.powerbi.com/view?r=eyJrIjoiNjQxZWZhOTItYzU1ZS00Y2QxLWE1ODAtOTViZjhmNjEyZjNiIiwidCI6ImY2MTBjMGI3LWJkMjQtNGIzOS04MTBiLTNkYzI4MGFmYjU5MCIsImMiOjh9">https://app.powerbi.com/view... https://app.powerbi.com/view?r=eyJrIjoiMjA1ZDA0N2YtOTUzMi00ZTU1LWFlMDAtMjFlMTVkN2U2ODQyIiwidCI6ImY2MTBjMGI3LWJkMjQtNGIzOS04MTBiLTNkYzI4MGFmYjU5MCIsImMiOjh9">https://app.powerbi.com/view...

9. #Immunity, #R0, #IFR, #Reinfection, #Vaccine, #Treatment are all uncertain and the data presented often preliminary or single site studies. But, given the above, is a #Herd_Immunity approach acceptable to YOU?