Ось стаття про проблеми з міряннями антитіл
The Flawed Science of Antibody Testing for SARS-CoV-2 Immunity
там і про нелінійність колеляції між рівнями антитіл та клітинним імунететом. і про те що тести не відкалібровані. Кажуть що тільки одна лаба в США зробила калібрування.
І саме головне, там купа рази пишуть що не рекомендують робити тести на антитіла.
Could a simple blood test reveal whether the vaccine was working or, later, if it was time for a booster shot?
No, says the US Food and Drug Administration (FDA), which discouraged antibody testing as a do-it-yourself immunity check in a communication to the public and clinicians this past spring. A spokesperson for the agency reiterated the position in an email to JAMA in September.
The SARS-CoV-2 serology tests that eventually received FDA Emergency Use Authorization (EUA) have demonstrated high sensitivity and specificity, but that accuracy is for detecting antibodies. Their ability to predict protection against the virus based on those antibodies hasn’t been proven. Plus, the FDA cautioned that some tests detect antibodies the immune system likely produces only after natural infection with the virus. Depending on the assay, people who weren’t previously infected could test negative for antibodies despite having vaccine–induced immunity.
For example, higher titers were associated with increased protection in 2 phase 3 studies: one not yet peer-reviewed of the mRNA-1273 (Moderna) vaccine and another of the ChAdOx1 nCoV-19 (Oxford/AstraZeneca) vaccine. Still, she wrote, “it’s not a simple relationship—there is no clear titer at which you can say whether a particular person is protected.” What’s more, different neutralizing antibody thresholds, or even different immune responses altogether, may correlate with protection against asymptomatic, symptomatic, or severe disease.
According to Theel, if and when correlates and thresholds of protection are determined, the tests will need to be standardized and calibrated, as has been done with antibody tests for other vaccine-preventable diseases, including tetanus, diphtheria, and measles. So far, only one commercially available SARS-CoV-2 antibody test, from Ortho-Clinical Diagnostics, has been calibrated to the World Health Organization’s reference standard, she said.
Відправлено через 3 хвилини :
І ось це найцініше
What’s more, all antibodies bind but only some neutralize, and almost none of the authorized clinical tests distinguish between them. Although some studies have shown a correlation between levels of binding and neutralizing antibodies, they’re still an imperfect match.
Тобто не всі антитіла мають нейтралізуючий ефект. І жоден тест не розріняє які саме у вас.
Це одна з причин чому по антитілам важко визначати кілтиттий імунітет, а отже і загальний імунітет.