Vaccinations of 4 Camelus dromederius starting 3rd Aug followed by 3 boosters at 14 day intervals against the foot and mouth disease virus (146S particle and recombinant nonstructural protein 3ABC).
High titres were obtained by the end of 3rd booster (19th Sep). Now I face some problems and need to immunize again - my queries are:
1) do you expect by this time (about 2 and a half months completed) the immune titres would have completely waned away?
2) if I am going to boost again, how many boosters should I give in order to attain good titre value?
I think it is relevant to amount of 146S particles and adjuvant that you have used. The both factors may affect the longevity of antibody response. You mentioned about high titres. Which titres you consider as high?
Hii.
It is important to know the titer values and also the problems faced by you in your experiment.
we faced similar problems in our case with dengue vaccine candidate, where only one serotype (DENV-2) was giving both, high antibody and neutralization titers. The three serotypes (DENV-1, -3 and -4) were not giving neutralization titers although they were giving high antibody titers in an indirect ELISA assay.
Just to check - are you getting good repeat results with the laboratory assay you are using to assess antibody titre?
Hello,
I advice you to check where are you compared to the international standards (FDA, pharmacopeé,...).
Good luck
A good inactivated viral vaccine is expected to induce protective immune response at least for 2 to 3 years.
I agree with Neelima,
Normally with an inactivated viral vaccine you should induce fairly long-lived immunity. The titers and longevity depends on several factors though, such as presence of T-dependent epitopes, avidity, immunostimulation (adjuvant effect) etc...
When you boost you mainly stimulate memory B cells (unless you mainly induce T-independent B cell responses which can lack a memory component). It should be enough with just one boost to reach peak titers again (4-7 days after the boost in mice and macaques).
The immunity may wane with the passage of time which may vary with the type, dose, route of administration and adjuvant used. Once the immunity was achieved and has not waned away fully you may get significant titers with a single injection of proper dode through proper route if the animal is healthy, well nourished and not immunocompromised due to other reasons.
- Badges
- Science topic
- Similar topics
- Medicine
- Disease
- Infectious Diseases
- Immunization
- Vaccination