Post Vaccination Neutralizing Antibody Test

Post Vaccination Neutralizing Antibody Test

COVID-19 Neutralizing Antibody Test

Test for antibodies that neutralize SARS-CoV-2, the virus that causes COVID-19. This is the only US FDA approved test to determine if you have functional neutralizing antibodies. Other IgG/IgM antibody tests do not give results on the functional or neutralizing aspect of the antibodies. Recommended for people after vaccination or after recovery from an active infection. Receive secure digital results in 3-5 business days.


Predictive models of immune protection against COVID-19 are urgently needed to identify correlates of protection to aid in future vaccine deployment. To address this, we analyzed the relationship between in vitro neutralization levels and observed protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using data from seven current vaccines and from convalescent cohorts. We estimate the neutralization level for 50% protection against detectable SARS-CoV-2 infection to be 20.2% of the median convalescent level (95% confidence interval (CI)  = 14.4–28, 4 %). The estimated level of neutralization required for 50% protection against severe infection was significantly lower (3% mean convalescent level; 95% CI = 0.7–13%, P = 0.0004).

Modelling of the decline in neutralization titer during the first 250 d after immunization predicts that a significant loss in protection against SARS-CoV-2 infection will occur, although protection against the severe disease should be largely maintained. Neutralization titers against some SARS-CoV-2 variants of concern are reduced compared to the vaccine strain, and our model predicts the relationship between neutralization and efficacy against viral variants. Here, we show that the level of neutralization is highly predictive of immune protection and provide an evidence-based model of immune protection against SARS-CoV-2 that will help develop vaccine strategies to control the future trajectory of the pandemic.

Who Should Be Tested?

  • Post-Vaccination

Take a neutralizing antibody test after your first dose of the COVID-19 vaccine and again after your second dose to check if your body produced neutralizing antibodies in response to the vaccine. For a vaccine that is 95% effective, 5,000 out of 100,000 people vaccinated will not be protected.

  • Post-Recovery

Were you infected with SARS-COV-2 (COVID-19)? The neutralizing antibody test can determine your immune system’s response to infection. Experts are still learning how long neutralizing antibodies remain in the blood after infection and whether you are protected against reinfection in the future.

  • Overall awareness

If you want to take a baseline test before vaccination or if you are just curious about your immune status, you are eligible for testing. Neutralizing antibody testing is available to frontline workers, healthcare workers, educators, and the general public.