SARS-CoV-2 Neutralizing Antibody Testing for Vaccine Efficacy Assessment

SARS-CoV-2 testing is now facing increasing challenges in the face of an ongoing pandemic with the emergence of new variants and waning vaccine immunity. Increasing evidence supports the correlation between neutralizing antibody titers and protection from this dangerous virus. Recent studies show that less than 40% of immunocompromised and less than 70% of elderly (over 80 years of age) people who are fully vaccinated elicit these protective antibodies. Furthermore, Israel’s early vaccination program exclusively using the Pfizer vaccine has shown waning population immunity after about six months post-vaccination leading to a dramatic uptick in infections particularly from the Delta variant. Thus triggering a third booster shot for people over the age of 50 in that country. This talk explores the key questions associated with the healthcare implications of SARS-CoV-2 and how a new approach to testing may help in determining individual, neutralizing antibody response to vaccination.

Learning Objectives:

1. Explain the principles of a new cPass surrogate virus neutralization test (cPass sVNT) and how it compares to the gold standard live cell virus neutralization tests such as the plaque- and foci-reducing neutralization tests.

2. Contrast the more traditional and commonly employed SARS-CoV-2 IgG binding assays with the functional cPass sVNT. 

3. Discuss the variation in efficacy of current SARS-CoV-2 vaccines and uncertainties in vaccinated populations concerning protection.