COVID抗体检测的意义

现在很多人都去检测COVID抗体，然后说自己抗体水平多高什么的，我看到很多文章说抗体水平和immunity不能挂钩：

1. https://www.fda.gov/medical-devi ... cination-fda-safety

While a positive antibody test result can be used to help identify people who may have had a prior SARS-CoV-2 infection, more research is needed in people who have received a COVID-19 vaccination. Currently authorized SARS-CoV-2 antibody tests have not been evaluated to assess the level of protection provided by an immune response to COVID-19 vaccination.

2. https://www.cvs.com/minuteclinic ... 19-antibody-testing

It is important to remember that COVID-19 antibody testing should not be used to determine or validate the effectiveness of a COVID-19 vaccine.

3. https://www.cdc.gov/coronavirus/ ... sts-guidelines.html

Antibody testing is not currently recommended to assess for immunity to SARS-CoV-2 following COVID-19 vaccination, to assess the need for vaccination in an unvaccinated person, or to determine the need to quarantine after a close contact with someone who has COVID-19. Some antibody tests will not detect the antibodies generated by COVID-19 vaccines. Because these vaccines induce antibodies to specific viral protein targets, post-vaccination antibody test results will be negative in persons without history of previous infection, if the test used does not detect antibodies induced by the vaccine.

4. https://www.cdc.gov/vaccines/cov ... considerations.html

Antibody testingexternal icon is not currently recommended to assess the need for vaccination in an unvaccinated person or to assess for immunity to SARS-CoV-2 following COVID-19 vaccination. Antibody tests currently authorized under an EUAexternal icon have variable sensitivity, specificity, as well as positive and negative predictive values, and are not authorized for the assessment of immune response in vaccinated people. Furthermore, the serologic correlates of protection have not been established, and antibody testing does not evaluate the cellular immune response, which may also play a role in vaccine-mediated protection.

If antibody testing was performed following vaccination, further doses of the same or different COVID-19 vaccines are not recommended based on antibody test results at this time. If antibody testing was done after the first dose of an mRNA vaccine, the vaccination series should be completed regardless of the antibody test result.

我的理解是， 抗体水平高可能是因为被感染过，但是不能证明一个人对病毒的免疫力。后者指的更多是当身体被感染到病毒后产生抗体的能力，这个目前是检测不出的（尤其对于mRNA类疫苗）。我不是学生物或医学的所以理解可能有误，所以希望专业人士能够发表下观点，如何解读抗体检测的结果。不过从以上官方文章来看我们不能根据检测结果做任何事（比如是否打加强针，是否放飞自我）。

反问一下就好了。抗体水平低，是否感染概率就高，答案应该是一致的。