Elephant WNV Vaccination Survey (sent out to SSP holding institutions Dec 2002)
Summary of Results (Aug 14, 2003)
Number of institutions responding: 15 institutions
1. Do you currently use the Ft. Dodge WNV vaccine in your elephants?
m yes-3 institutions vaccinate
m no-12 do not vaccinate
2. If yes, what dose and route do you use?
m 1 ml-one institution used 1ml dose IM
m 2 ml-two institution has used 2ml SQ
3. Did you administer two initial vaccinations as recommended on the label (2-4 weeks apart)?
m no-one respondent vaccinated 3 times at 3-4 week intervals; one respondent vaccinated 3 times at 3 and 4 weeks after initial vaccination; other respondent did not specify schedule
4. How often do you plan to repeat immunizations?
m annually-two respondent
m twice per year m more frequently
m don’t know – one respondent
5. Did you observe any adverse reactions to vaccination?
m yes m no-two respondent If yes, describe:
6. Have you measured post-vaccination antibody titers?
m yes – one respondent m no-one respondent
7. If so, were detectable antibody titers present (use >1:40 as cutoff for viral neutralization titer)? - 1/3 elephants seropositive at 3 wks after 1st vaccine; 2/3 serpositive one week after 2nd booster (booster administered at 3 wks); 3/3 seropositive at 1 month after 3rd booster (booster administered 1 wk after 2nd booster)
m yes m no
8. Number of Asian elephants vaccinated ___3____; not vaccinated ____17__
Number of African elephants vaccinated ___5_; not vaccinated _____26_
9. Are you vaccinating any other species?
m yes ___________________ m no
Current data show that at least 3 Asian elephants have seroconverted in response to vaccination with the equine product using 2 ml SQ at 0,3,4 weeks. Antibody titers in WNV-vaccinated African elephants are currently unknown.
Unvaccinated elephants have seroconverted using both the serum neutralization screening assay (+ is considered any titer at or above 1:40) and hemagglutination inhibition (+ is considered any titer at or above 1:20).
Known seropositive cases: 1 adult female African elephant 1:320 (SN)
3 adult African elephants 1:20 (HI)
2 Asian elephants – positive titer (number and test unknown)
Results from elephant samples sent to Cornell prior to August 2002 –
0/15 elephants are seropositive
Current data is insufficient to determine if elephants should be vaccinated with the WNV vaccine. On limited data, no adverse effects have been observed and a post-vaccinal titer has occurred in 3 vaccinated Asian adults.
All institutions holding elephants should consider monitoring WNV titers in their herds.