5 ms·

p(i|v) = ( p(v|i) * p(i) ) / p(v) p(v|i) = 0.6 p(v) = 0.6 p(i) = ?; but it's high (record case counts) p(i|v) = p(i); high If Israel has a 60% vaccina

p(i|v) = ( p(v|i) * p(i) ) / p(v) p(v|i) = 0.6 p(v) = 0.6 p(i) = ?; but it's high (record case counts) p(i|v) = p(i); high If Israel has a 60% vaccination rate, and 60% of those in the hospital are vaccinated, then doesn't this mean the vaccine has no effect on the chances of being hospitalized?

pgalvin 5y ago
No, because you assume that a 10 year old has an equal probability of being hospitalised as a 90 year old (for example). Israel has a low overall vaccination rate because they have a very young population. If you restrict the sample to just >50 year olds (majority of hospitalisations), then both statistics look very different.
- nradov 5y ago
  Based on CDC data a 90 year old has at least 30× the risk of hospitalization compared to a 10 year old. https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burd...
mint2 5y ago
That is why considering age is important and why interacting variables make it so easy for statistics to mislead when talking to people who are less verse or aren’t aware of the topic being studied. About 78% of those above 12 are vaccinated in Israel, and the rate is even higher for those more susceptible to the virus. Without quantifying those factors, it’s going to lead to a garbage in garbage out assessment.
jonnycomputer 5y ago
Well, the article says 78% of people 12 yo and older are vaccinated in Israel. Not sure what percent if you drop it to include everyone. 87% of those who were hospitalized were 60 or older (which doesn't match the general population). I imagine that vaccination rates are much much higher than 60% among those over 60. In the US its around 80%. But also, hospitalizations are much more likely the older you get. Moreover (and this was the point of the paper the article was discussing), the effectiveness of the vaccine may dwindle with time, and the 60+ crowd were among the first to get vaccinated. So, no, I don't think you can do so simple a calculation and conclude that. Instead of back of the envelope estimates, I think I'd just point to this study: https://www.nejm.org/doi/full/10.1056/NEJMoa2108891 https://www.nejm.org/doi/full/10.1056/NEJMoa2108891 Abstract: Background The B.1.617.2 (delta) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), has contributed to a surge in cases in India and has now been detected across the globe, including a notable increase in cases in the United Kingdom. The effectiveness of the BNT162b2 and ChAdOx1 nCoV-19 vaccines against this variant has been unclear. Methods We used a test-negative case–control design to estimate the effectiveness of vaccination against symptomatic disease caused by the delta variant or the predominant strain (B.1.1.7, or alpha variant) over the period that the delta variant began circulating. Variants were identified with the use of sequencing and on the basis of the spike (S) gene status. Data on all symptomatic sequenced cases of Covid-19 in England were used to estimate the proportion of cases with either variant according to the patients’ vaccination status. Results Effectiveness after one dose of vaccine (BNT162b2 or ChAdOx1 nCoV-19) was notably lower among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7); the results were similar for both vaccines. With the BNT162b2 vaccine, the effectiveness of two doses was 93.7% (95% CI, 91.6 to 95.3) among persons with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) among those with the delta variant. With the ChAdOx1 nCoV-19 vaccine, the effectiveness of two doses was 74.5% (95% CI, 68.4 to 79.4) among persons with the alpha variant and 67.0% (95% CI, 61.3 to 71.8) among those with the delta variant. Conclusions Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses. Absolute differences in vaccine effectiveness were more marked after the receipt of the first dose. This finding would support efforts to maximize vaccine uptake with two doses among vulnerable populations. (Funded by Public Health England.)
- deleted 5y ago
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- Buttons840 5y ago
  Yeah, I got the overall vaccination rate from Google (60%), but as you say, the differences in age groups matter.
  - deleted 5y ago
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pgalvin 5y ago

No, because you assume that a 10 year old has an equal probability of being hospitalised as a 90 year old (for example). Israel has a low overall vaccination rate because they have a very young population. If you restrict the sample to just >50 year olds (majority of hospitalisations), then both statistics look very different.

nradov 5y ago
Based on CDC data a 90 year old has at least 30× the risk of hospitalization compared to a 10 year old. https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burd...

mint2 5y ago

That is why considering age is important and why interacting variables make it so easy for statistics to mislead when talking to people who are less verse or aren’t aware of the topic being studied. About 78% of those above 12 are vaccinated in Israel, and the rate is even higher for those more susceptible to the virus. Without quantifying those factors, it’s going to lead to a garbage in garbage out assessment.

jonnycomputer 5y ago

Well, the article says 78% of people 12 yo and older are vaccinated in Israel. Not sure what percent if you drop it to include everyone. 87% of those who were hospitalized were 60 or older (which doesn't match the general population). I imagine that vaccination rates are much much higher than 60% among those over 60. In the US its around 80%. But also, hospitalizations are much more likely the older you get. Moreover (and this was the point of the paper the article was discussing), the effectiveness of the vaccine may dwindle with time, and the 60+ crowd were among the first to get vaccinated. So, no, I don't think you can do so simple a calculation and conclude that. Instead of back of the envelope estimates, I think I'd just point to this study: https://www.nejm.org/doi/full/10.1056/NEJMoa2108891 https://www.nejm.org/doi/full/10.1056/NEJMoa2108891 Abstract: Background The B.1.617.2 (delta) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), has contributed to a surge in cases in India and has now been detected across the globe, including a notable increase in cases in the United Kingdom. The effectiveness of the BNT162b2 and ChAdOx1 nCoV-19 vaccines against this variant has been unclear. Methods We used a test-negative case–control design to estimate the effectiveness of vaccination against symptomatic disease caused by the delta variant or the predominant strain (B.1.1.7, or alpha variant) over the period that the delta variant began circulating. Variants were identified with the use of sequencing and on the basis of the spike (S) gene status. Data on all symptomatic sequenced cases of Covid-19 in England were used to estimate the proportion of cases with either variant according to the patients’ vaccination status. Results Effectiveness after one dose of vaccine (BNT162b2 or ChAdOx1 nCoV-19) was notably lower among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7); the results were similar for both vaccines. With the BNT162b2 vaccine, the effectiveness of two doses was 93.7% (95% CI, 91.6 to 95.3) among persons with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) among those with the delta variant. With the ChAdOx1 nCoV-19 vaccine, the effectiveness of two doses was 74.5% (95% CI, 68.4 to 79.4) among persons with the alpha variant and 67.0% (95% CI, 61.3 to 71.8) among those with the delta variant. Conclusions Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses. Absolute differences in vaccine effectiveness were more marked after the receipt of the first dose. This finding would support efforts to maximize vaccine uptake with two doses among vulnerable populations. (Funded by Public Health England.)

deleted 5y ago
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Buttons840 5y ago
Yeah, I got the overall vaccination rate from Google (60%), but as you say, the differences in age groups matter.
- deleted 5y ago
  [deleted]