This article was written with contributions from Charlotte Irwin. Charlotte is a Research Strategist on the ETF and Mutual Fund Research Team.
It’s that time of year. After relaxing holiday breaks spent visiting with family and friends, everyone’s back in the office full of unbridled optimism – and germs. And all the ensuing coughing, sniffling and shivering can mean only one thing: It’s flu season.
While the flu circulates all year, activity generally peaks from December through February. And with between 4.6 million and 6.6 million people already stricken, the CDC has warned that this season is on track to be as severe as 2017-2018, when 45 million flu cases made that season one of the deadliest in a decade. Given that the US economy has recently relied so heavily on consumer strength, too many sick days could drag on already slowing growth.
Good news, bad news
So far, the two major measures of the flu’s severity — hospitalizations and deaths — remain modest. However, the flu could spread rapidly and intensify in the coming weeks, especially because this season's flu vaccine is no match for the viral strain now dominating flu activity across the US. Even when vaccine development correctly anticipates the circulating viruses, the flu shot’s effectiveness is only about 60%. In comparison, the measles vaccine is 97% effective with two doses.1
The abnormality of this flu season is that the B strain of the virus, which typically doesn’t surface until the end of the season, is currently causing the illness in most parts of the country. More typically, the A strain of influenza dominates the early months. The upside is that strain B poses less of a danger than the more common A strain does to people 65 and older, who generally make up the majority of flu hospitalizations and deaths. However, the unusual early appearance of strain B flu has sickened many children.2