Nearly a quarter of the people in Delhi, India, who
volunteered for the COVID-19 virus test vaccine already had antibodies, which automatically
eliminated them from vaccine studies.
This presents a dilemma for vaccine developers because, if a
person already has the antibodies in their body, then it’s difficult to assess
whether the vaccine helps trigger an immune reaction, which is what vaccines are
designed to do. In essence vaccines are not a cure or a treatment for a disease
but, rather, they’re only intended to prevent the disease by prompting
immunity.
Source: Times
of India July 25, 2020