Flu Season 2019-2020

Influenza viruses are negative-sense single stranded RNA viruses of the Orthomyxoviridae family. There are four types of influenza viruses: A, B, C and D . In electron microscopy these types, especially A and B,  could be virtually indistinguishable. D is more similar to C.

Most of these viruses look like small spheres with spikes, although some could be irregularly shaped. Spikes are proteins and they are what's different in different forms of influenza. Typically, influenza A starts the early wave of the flu, and influenza B starts to show up at the tail-end of the season, in early spring. This year is't flu B that started the first wave while flu A may be responsible for the second wave. Is the flu shot working? It's still too early to predict.