Question

Why are multiple vaccine doses still needed even if the adjuvant is present in the vaccine?

Answer 1

Adjuvant : An adjuvant is an ingredient substance used in most of the vaccines that creates a stronger immune response in people who have received the vaccine .

Primary Response of Vaccination:

▪︎ Low affinity to their antigen

▪︎There is long Lag phase for the production of antibody and its effect may be seen after long time

▪︎Few antibodies are produced in the primary immune response even though we use adjuvant as compared to secondary responses.

▪︎The primary immune response is usually weaker than secondary immune response even we use adjuvant in primary dose

▪︎Antibody level declines to the point where it may be undetectable.

Secondary and Further dose responses ( Booster Doses)

Differs from primary response:

▪︎Short latent period

▪︎Rapid production of antibody

▪︎Abundant antibody

▪︎Maintained at higher level and for longer time

▪︎Greater capacity to bind to antigen

●● As we need lifelong protection against various pathogens , therefore we need strong immunization which may not be fulfilled by single vaccination even if u use adjuvant . Adjuvant can enhance primary response for sure but may not cancel the booster doses which are much needed . As in children , they need lifelong protection . So there are various vaccination schedules which include multiple vaccinations like MMR .Children receive the first dose of the MMR vaccine between 12 and 15 months and the second before they go to school, around age 4 to 6. ●●