HSV529 immunization protects HSV-1-primed guinea pigs from effects of HSV-2 vaginal challenge.

<p>Guinea pigs were inoculated with HSV-1 (KOS strain; 10⁶ CCID₅₀; n = 30) or PBS (n = 18) by the intranasal route on day 0. All animal inoculated with HSV-1 were positive for HSV-1 at week 5. At weeks 7 and 10, animals inoculated with HSV-1 were immunized with HSV529 (10⁶ CCID₅₀; n = 15) or PBS (n = 14) by the i.m. route. At week 14, all animals except 3 PBS controls were challenged with an intravaginal inoculation of HSV-2 (G strain, 2 x 10⁶ CCID₅₀). (A) Mean body weight change after HSV-2 challenge. (B) Mean vaginal lesion score after HSV-2 challenge. (C) Percent survival after HSV-2 challenge. (D) HSV-2 viral shedding after challenge. (E) Cumulative number of recurrent lesions per animal. *Dead or euthanized animal. Error bars represent standard error of the mean.</p

HSV529 does not propagate in the brains of 4−6-day-old suckling mice.

<p>Four- to 6-day-old sucking mice received an intracranial injection of vaccine buffer (gray squares), HSV529 (gray triangles, 5 x 10⁵ CCID₅₀), or wild-type (wt) HSV-2 186 syn+-1 (black circles, 10 CCID₅₀). Brains were collected on p.i. days 0 (4 hours p.i.), 2, 4, 6, and 14, and from animals that died during the experiment. The titer of each animal is represented by an individual symbol and the mean titer is represented by a horizontal bar. Virus titers were determined on AV529-19 cells.</p

HSV529 immunization protects guinea pigs from the effects of HSV-2 vaginal challenge.

<p>Guinea pigs were immunized with HSV529 (10⁶ CCID₅₀; n = 30) or PBS (n = 25) by the i.m. route on days 0 and 21. On day 48, 15 animals in each group were challenged with an intravaginal inoculation of HSV-2 (G strain; 10⁵ CCID₅₀). The remaining animals received a mock challenge of PBS. (A) Mean body weight change after HSV-2 challenge. (B) Mean vaginal lesion score after HSV-2 challenge. (C) Percent survival after HSV-2 challenge. (D) HSV-2 viral shedding after challenge. (E) Cumulative number of recurrent lesions per animal. *Dead or euthanized animal. Error bars represent standard error of the mean.</p

Mice immunized with HSV529 produce HSV-2-specific IgG1 and IgG2a antibodies, neutralizing antibodies, and HSV-2-specific splenic lymphocytes secreting IFNγ and IL-5.

<p>BALB/c mice (n = 10/group) were immunized with HSV529 (10⁴ CCID₅₀, 10⁵ CCID₅₀, or 10⁶ CCID₅₀) or PBS by the i.m. route on days 0 and 21. Sera were collected on days 21 (D21; n = 10) and 41 (D41; n = 5). (A) HSV-2-specific IgG1 and IgG2a antibody titers in the sera were determined by ELISA using a lysate prepared from HSV-2-infected Vero cells and secondary antibodies specific for mouse IgG1 and IgG2a. (B) HSV-2 neutralizing antibodies in the sera were measured by preincubating dilutions of heat-inactivated sera with 100 CCID₅₀ of live HSV-2 (strain G) virus for 1 hour prior to infection of Vero cell cultures. Infected cells were detected with anti-HSV glycoprotein D antibodies. The serum dilution that neutralized 50% of the virus (SN₅₀) was determined by plotting the neutralization activity versus the serum dilutions. Splenic lymphocytes secreting IFNγ (C) or IL-5 (D) in response to <i>ex vivo</i> stimulation with heat-inactivated HSV-2 (strain G) were counted using an ELISPOT assay. Error bars represent standard error of the mean.</p