The toxoplasmosis epidemic hit around the same time as the flu vaccine season got started. Although live vaccines don't cause disease in the people who get them because they are made with weakened viruses and bacteria, there is always a concern that someone with a severely weakened immune system could get sick after getting a live vaccine. That is why live vaccines are not given to people who have a weakened immune system. People who were infected with the toxoplasmosis parasite displayed symptoms of the influenza virus. So almost everyone thought we had a flu epidemic going around. People getting the flu vaccine already had a weakened immune system, thus pushing them further into sickness with the live flu vaccine. This somehow sent the toxoplasmosis parasite into overdrive and caused it to wreak havoc.