“There are two sides to the coin” is an adage we use a lot in immunology: the immune system has many molecules and mechanisms that desirably protect us against infection, but each one also has a downside that can result in unwanted symptoms or disease.

In the “desirable” category, immunologists are starting to use the innate, or built-in, immune system to identify adjuvants, substances that enhance the efficacy of vaccines. The article from New Scientist (“Vaccines Set to Target Immune Panic Button”) covers research in this area.

British researchers are designing vaccines that contain an adjuvant to trigger an innate immune pathway called RIG-I. This pathway allows the body to produce interferon to protect itself against viral infection. When interferon is made by the right cells and in the right amounts, it can also serve as an effective adjuvant, according to current research.

On the other hand, the innate immune system can go into overdrive and produce dangerously high, sometimes lethal amounts of cytokines, immune system substances that would be protective in small amounts. An excess is called a “cytokine storm.”

An article from the scientific literature reports on a team of scientists from Canada and Japan that studied what happens when the 1918 pandemic influenza virus infects monkeys, a close model to infection in humans (“Influenza: Fatal Immunity and the 1918 Virus”). They found that the pandemic strains have a one-two punch.