diff --git a/code/modules/virus2/disease2.dm b/code/modules/virus2/disease2.dm
index b01f422bf1..644d0f492a 100644
--- a/code/modules/virus2/disease2.dm
+++ b/code/modules/virus2/disease2.dm
@@ -38,7 +38,7 @@
 	if(mob.stat == 2)
 		return
 	if(stage <= 1 && clicks == 0) 	// with a certain chance, the mob may become immune to the disease before it starts properly
-		if(prob(20))
+		if(prob(5))
 			mob.antibodies |= antigen // 20% immunity is a good chance IMO, because it allows finding an immune person easily
 		else
 	if(mob.radiation > 50)