Pandemics are already something of a horror, at least an existential one for modern-day audiences, and having a sick child is certainly a terrifying thought for all parents. Given all these problems are very real and scary, modern-day parents turn out to be even more protective of their children or become “helicopter parents.” And it seems like all these contemporary ideas are folded together in the new horror thriller “Blood” by genre filmmaker Brad Anderson best known for directing “The Machinist” with Christian Bale.