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    Home > Active Ingredient News > Infection > What is the effect of Sinopharm inactivated vaccine?

    What is the effect of Sinopharm inactivated vaccine?

    • Last Update: 2021-06-11
    • Source: Internet
    • Author: User
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    About the wonderful screening of clinical phase III data.
    .
    .
    The results of the recent phase III clinical trial of Sinopharm's new crown virus inactivated vaccine were published in JAMA, and the protective effect against symptomatic new crown infection was 72.
    8% (95% confidence interval: 58.
    1%) -82.
    4%) and 78.
    1% (95% confidence interval: 64.
    8%-86.
    3%) such a pretty good result.

    However, some researchers soon discovered that the clinical endpoint selected by the so-called "symptomatic infection" of the Sinopharm's new coronavirus vaccine trial is different from the clinical endpoint selected by Pfizer and other foreign vaccines, and this difference has caused it.
    Controversy over true validity.

    What are the different clinical endpoints? The main text of the paper published in JAMA, on the surface, is no different from the statement published by Pfizer in NEJM and other journals in the result presentation, and both use the term "symptomatic infection".

    But in fact, the definition of symptomatic infection is different between the two parties.
    In the clinical phase III study of Pfizer and other vaccines, “symptomatic infection” means one of the symptoms such as cough, fever, fatigue, etc.
    and the nucleic acid is positive, while the national medicine vaccine In phase III clinical studies, "symptomatic infections" are more stringent, requiring not only nucleic acid positives and single symptoms, but also more complex clinical evaluations.
    When screening vaccine-infected patients, "Chinese experts suspect it is not counted", even if nucleic acid If they are positive, they will also be eliminated.

    Sinopharm’s standard: clinical diagnosis of suspected cases should be performed according to classification, and Pfizer’s standard for nucleic acid positive: only one symptom plus nucleic acid positive is required.
    Therefore, Sinopharm’s phase III clinical research endpoint can be said to be “infected” The judgment is much stricter than Pfizer.

    Therefore, as stated in the JAMA paper, these vaccines cannot be directly compared-after all, even the criteria for determining infection are different, how to compare.

    If the standards are unified, how will the data change? Assuming that the phase III clinical endpoint of Sinopharm and Pfizer's phase III clinical endpoint will affect the data of "protective efficacy against symptomatic new crown infection"? How does it affect? We can make a rough assessment based on the table issued by Sinopharm in the attachment-in the official paper, the numbers used by Sinopharm to calculate the protective efficacy are 26 (WIV04), 21 (HB02) and 95 (placebo group) These three numbers finally came to the result of WIV04 protective effect 72.
    8% (95% confidence interval: 58.
    1%-82.
    4%) and HB02 protective effect 78.
    1% (95% confidence interval: 64.
    8%-86.
    3%).

    Looking back at the above table, we can see that the data that was finally adopted has gone through layers of screening.

    At the beginning, there were 308 suspected cases in the WIV04 group, 265 suspected cases in the HB02 group, and 389 suspected cases in the placebo group.

    After PCR nucleic acid screening, 127 cases were positive in the WIV04 group, 90 cases were in the HB02 group, and 203 cases were in the placebo group.

    After that, asymptomatic infections and positive patients who did not meet the research regulations or were suspected by experts were excluded twice (excluded once by UAE experts and again by Chinese experts), and the number of infected persons who met the regulations were 69, 48, and 138.
    .

    The release of the 26, 21, and 95 data sets was again filtered through the "observation time window" standard.

    If calculated by 69, 48, and 138, a rough estimate is that the protective effect of WIV04 on symptomatic new coronary pneumonia (clinically confirmed) is about 50%, and that of HB02 is about 65%.

    It is 51% consistent with the recent WHO data released by Kexing.

    If calculated based on the Pfizer vaccine standard, the number of nucleic acid-positive people minus the number of asymptomatic infections is the number of symptomatic infections.

    Then, the number of symptomatic infections in the WIV04 group was 95, the HB02 group was 66, and the placebo group was 148.

    If we exclude those who are positive for baseline PCR, they are 94, 64, and 148.

    Calculated by 94, 64 and 148, the effective protection of WIV04 against symptomatic infections is approximately 36.
    5%, and that of HB02 is approximately 55.
    4%.
    This data is only a rough estimate.

    From the above calculations, we can see that roughly, if you choose the same end point as Pfizer, the protective effect of WIV04 will change from 72.
    8% (95% confidence interval: 58.
    1%-82.
    4%) to 36.
    5%, and the protective effect of HB02 will change from 78.
    1%.
    (95% confidence interval: 64.
    8%-86.
    3%) has roughly become 55.
    4%, which has fallen below the lower limit of the confidence interval using another set of standards as the end point.

    In addition, the data Pfizer used Pfizer's standard to make is that in people who have not been infected with the new coronavirus in the past, the protective effect against symptomatic infection after two injections is 95.
    0% (95% confidence interval is 90.
    3%-97.
    6%).
    For reference.

    Finally, attach a doctor’s evaluation.

    Welcome everyone to discuss.

    References[1]https://
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