Some more covid vaccine math
Sep. 23rd, 2023 10:16 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
izardSome may think that I am beating a dead horse here, but the horse isn't dead until there are still active covid vaccine mandates in the USA.
According to CDC director's recent public announcement
at 1:01. "teen boys have been up to 5 times as likely to have heart inflammation after having covid infection than after getting vaccinated". There are several peer reviewed publications that estimate this difference in this age group, and she selected the one which resulted in estimate of 2x-5x, and took the highest number.
Here is a quote from another study (SARS-CoV-2 Vaccination and Myocarditis in a Nordic Cohort Study of 23 Million Residents, April 20, 2022): "Among males aged 16 to 24 years of age, the excess number of Myocarditis events within the 28-day risk period was 27.49(14.41 to 40.56) per 100 000 vaccinated. Excess events of myocarditis were 1.37 (−0.14 to 2.87) events per 100 000 individuals with a positive test result among males aged 16 to 24 years". So it is not 5x, but rather 20X other way around.
But let's just trust CDC and assume that 5x is the correct number.
Let the probability of heart inflammation after getting vaccinated is X, and probability of heart inflammation after having covid infection is then 5X.
CDC stops here and gives the recommendation which then translated to mandates, but why they don't continue calculation to estimate the final risk?
If I chose to vaccinate my teen son, the probability of heart inflammation from vaccine is X.
If I chose not to vaccinate my teen son, the probability of heart inflammation from covid is 5X multiplied by (probability of getting covid) multiplied by (vaccine effectiveness in preventing covid).
My son, like 96% of US children has already some immune memory of covid (from prior infection in his case). Like for 99.99%+ US children who had covid it was a mild cold for him, much milder than RSV or flu. He is not vaccinated and had covid once, while he lived through many covid peaks in Germany and USA. I estimate that in the current seasonal peak his odds of having covid again is 10%. But for the sake of argument let's assume it is much more, e.g. 25%, or 0.25.
I trust CDC that the vaccine is very effective in preventing severe decease and death. Not so much in preventing infection, but let's assume it is as effective as flu vaccine and prevents ~50% of cases.
So finally, the probability of heart damage for non-vaccinated teen boy is 5*0.25*0.5*X=0.63X.
0.63X < X, so not vaccinating a teen boy seems to be the right decision. But wait, there is more! If I chose to vaccinate my child, the probability of heart inflammation is not actually X, but X + 5X * (probability of getting covid) * (1 - vaccine effectiveness in preventing covid) * (1 - vaccine effectiveness in preventing severe covid that leads to heart damage).
I'll assume vaccine effectiveness in preventing severe covid leading to heart damage is 99%. It is likely less, but we all trust CDC that it is very effective.
So it is then X+5X*0.25*0.5*0.01=1.06X.
0.63X is still less than 1.06X.
According to CDC director's recent public announcement
at 1:01. "teen boys have been up to 5 times as likely to have heart inflammation after having covid infection than after getting vaccinated". There are several peer reviewed publications that estimate this difference in this age group, and she selected the one which resulted in estimate of 2x-5x, and took the highest number.
Here is a quote from another study (SARS-CoV-2 Vaccination and Myocarditis in a Nordic Cohort Study of 23 Million Residents, April 20, 2022): "Among males aged 16 to 24 years of age, the excess number of Myocarditis events within the 28-day risk period was 27.49(14.41 to 40.56) per 100 000 vaccinated. Excess events of myocarditis were 1.37 (−0.14 to 2.87) events per 100 000 individuals with a positive test result among males aged 16 to 24 years". So it is not 5x, but rather 20X other way around.
But let's just trust CDC and assume that 5x is the correct number.
Let the probability of heart inflammation after getting vaccinated is X, and probability of heart inflammation after having covid infection is then 5X.
CDC stops here and gives the recommendation which then translated to mandates, but why they don't continue calculation to estimate the final risk?
If I chose to vaccinate my teen son, the probability of heart inflammation from vaccine is X.
If I chose not to vaccinate my teen son, the probability of heart inflammation from covid is 5X multiplied by (probability of getting covid) multiplied by (vaccine effectiveness in preventing covid).
My son, like 96% of US children has already some immune memory of covid (from prior infection in his case). Like for 99.99%+ US children who had covid it was a mild cold for him, much milder than RSV or flu. He is not vaccinated and had covid once, while he lived through many covid peaks in Germany and USA. I estimate that in the current seasonal peak his odds of having covid again is 10%. But for the sake of argument let's assume it is much more, e.g. 25%, or 0.25.
I trust CDC that the vaccine is very effective in preventing severe decease and death. Not so much in preventing infection, but let's assume it is as effective as flu vaccine and prevents ~50% of cases.
So finally, the probability of heart damage for non-vaccinated teen boy is 5*0.25*0.5*X=0.63X.
0.63X < X, so not vaccinating a teen boy seems to be the right decision. But wait, there is more! If I chose to vaccinate my child, the probability of heart inflammation is not actually X, but X + 5X * (probability of getting covid) * (1 - vaccine effectiveness in preventing covid) * (1 - vaccine effectiveness in preventing severe covid that leads to heart damage).
I'll assume vaccine effectiveness in preventing severe covid leading to heart damage is 99%. It is likely less, but we all trust CDC that it is very effective.
So it is then X+5X*0.25*0.5*0.01=1.06X.
0.63X is still less than 1.06X.
no subject
Date: 2023-09-23 07:29 pm (UTC)no subject
Date: 2023-09-23 07:35 pm (UTC)Everyone I know personally had covid. Those unvaccinated mostly had it once.
no subject
Date: 2023-09-24 05:59 am (UTC)Adjusted IRRs comparing the 28-day risk periods following first and second doses compared with unvaccinated periods were 1.38 (95% CI, 1.12-1.69) for the first dose of BNT162b2 and 1.75 (95% CI, 1.43-2.14) for the second dose, and 1.16 (95% CI, 0.69-1.93) for the first dose of mRNA-1273 and 6.57 (95% CI, 4.64-9.28) for the second dose. Among males, after the first and second doses, adjusted IRRs were 1.40 (95% CI, 1.09-1.80) for the first dose of BNT162b2 and 2.04 (95% CI, 1.61-2.58) for the second dose, and 1.45 (95% CI, 0.84-2.52) for the first dose of mRNA-1273 and 8.55 (95% CI, 6.40-11.41) for the second dose. Among females, following the first and second doses, adjusted IRRs were 1.46 (95% CI, 1.01-2.11) for the first dose of BNT162b2 and 1.25 (95% CI, 0.77-2.05) for the second dose, and 1.45 (95% CI, 0.35-5.97) for the first dose of mRNA-1273 and 2.73 (95% CI, 1.27-5.87) for the second dose.
те, в среднем у группы допустим 16 летних, миокардит от разных причин случается 500 случаев на 110 тыс человек. когда людей привили вакциной, по сранвению с этими неприитыми 9а не с теми кто не привит и заболео ковидом) уних повсилась частота миокрадита, получилсь не 500 случаев в группе, а 600. вот вырос риск
We also estimated the excess numbers of myocarditis events per 100 000 vaccinees in the 28-day risk periods. Among all males, these numbers were 0.27 (95% CI, 0.09-0.46) events after the first dose of BNT162b2 and 0.67 (95% CI, 0.46-0.88) events after the second dose, and 0.33 (95% CI, −0.11 to 0.78) events after the first dose of mRNA-1273 and 4.97 (95% CI, 3.62-6.32) events after the second dose.
в этой статье вообще нет речи о тех кто болел ковидом и заимел миокрадиты (а вы исходите из этого постулата и чтото там сравниваете с этим показателем).
no subject
Date: 2023-09-24 06:03 am (UTC)Чтобы не спорить именно об этих цифрах, я просто взял 5x от CDC в посте. (CDC кстати тоже взяли 5x, хотя в статье, откуда они взяли 5x, результат был "от 2x до 5x")
no subject
Date: 2023-09-24 06:24 am (UTC)вот то же
teen boys have been up to 5 times as likely to have heart inflammation after having covid infection than after getting vaccinated"
черным по белому- после ковида у тинейджеров шансы на миокрадит в 5 раз выше, чем получить миокрадит от прививки от ковида (если они привились).
а в статье что вы ссылаетесь, оценивается, что при прививке от ковида в течении месяца после, если принять частоту миокардита в популяции за 1, частота миокрадита в группе у подростков будет 1.2 - 1.4. прирост на 0.4, допустим.
СДС вам же говорит, что риск миокардита от ковида в 5 раз выше, чем от прививки.
0.4х5=2. это значит, что риск миокардита в когорте болевших ковидом составиит 3, в когорте привитых- 1.4. т.е условно, если даже размазать вместе с фоном, то разница в 2 раза (1.4 по сравению с 3, риски растут если болеть ковидом, ане от прививки от ковида). при вашем хитром подсчете вдруг откда ни возбмись выросло 10 тыс. причем, в обратную сторону... это совсем не черипикинг.
no subject
Date: 2023-09-24 06:29 am (UTC)Статья - вообще red herring, я не использую данные из нее в подсчете 5*0.25*0.5*X=0.63X
no subject
Date: 2023-09-24 06:44 am (UTC)на мой взгляд, пригодится: где то там имейте ввиду, задней мыслью, что СДС в том, что от ковида проблем с сердцем больше, чем от прививки от ковида (включая подростков) вас не обмауло. лучше отталкиваться от реальности, чем от конспирологической теории.
no subject
Date: 2023-09-24 06:47 am (UTC)no subject
Date: 2023-09-25 05:07 am (UTC)Это не так: цитата из статьи - "In a complementary analysis, we studied incident myocarditis within 28 days following SARS-CoV-2 infection from August 1, 2020, to end of study. " "During the 28-day risk period after a positive SARS-CoV-2 test ... Excess events of myocarditis were ... 1.37 (95% CI, −0.14 to 2.87) events per 100 000 individuals with a positive test result among males aged 16 to 24 years.
Сравниваю с
"Among males 16 to 24 years of age, the excess number of myocarditis events per 100 000 vaccinees in the 28-day risk periods ... was 18.39 (95% CI, 9.05-27.72) events after the second dose (Table 2"
Никак в 5 раз не получается, скорее наоборот. И вывод из статьи - "... this risk should be balanced against the benefits of protecting against severe COVID-19 disease"