There’s been so little flu transmission during the COVID-19 pandemic that some types of flu virus may have gone extinct. During the COVID-19 pandemic, flu cases have dropped to historic lows, a phenomenon experts attribute to mask wearing and other precautions to combat the novel coronavirus.
Interestingly, two types of flu virus haven’t shown up on anyone’s radar for a year, meaning there have been no reported cases of these viruses anywhere in the world. Experts don’t yet know if these types have gone extinct, but if so, officials could have an easier time picking the strains of flu virus included in the flu vaccine.
To explain which flu viruses may have gone extinct, it helps to understand how flu viruses are classified. Two families of flu virus cause seasonal flu: influenza A and influenza B. Influenza A viruses are divided into ‘subtypes’ based on two proteins on their surfaces known as haemagglutinin (H) and neuraminidase (N). Currently, H1N1 and H3N2 circulate in people, and each of these subtypes is further broken down into ‘clades’. Influenza B viruses, on the other hand, don’t have subtypes or clades, but are divided into two lineages known as B/ Yamagata and B/Victoria.