Table 1.

Comparison of neutralizing antibody titers in sera from experimentally infected horses and mice using wt and chimeric challenge EEEVs in PRNT80

Sample type (virus used in experimental infection)/sample no.Neutralizing antibody titera with the following challenge virus:
wt NA EEEV FL93-939wt SA EEEV Br85SINV/NA EEEVSINV/SA EEEV
Horse serum (wt NA EEEV FL93-939)
    1 (D0)b<20NTc<20NT
    1 (D5)160NT40NT
    2 (D0)<20NT<20NT
    2 (D5)320NT20NT
    3 (D0)<20NT<20NT
    3 (D7)640NT80NT
    4 (D0)<20NT<20NT
    4 (D7)20NT20NT
Mouse serum (SINV/NA EEEV)
    1160NT160NT
    220NT20NT
    340NT80NT
    4160NT160NT
    5320NT320NT
    6640NT80NT
Mouse serum (SINV/SA EEEV)
    1NT320NT80
    2NT320NT160
    3NT40NT40
    4NT320NT320
    5NT160NT80
Normal mouse serum<20<20<20<20
  • a Neutralizing antibody titer is expressed as the reciprocal of the endpoint serum dilution that neutralized the challenge virus plaque count by 80%. The LLOQ was a neutralizing antibody titer of 20; <20, no detectable titer at the LLOQ.

  • b Values in parentheses are the number of days (D) postinoculation when serum was collected.

  • c NT, not tested.