Influenza activity has been widespread in North Carolina since late November. So far, the predominant virus circulating in North Carolina has been the influenza A (H3N2) virus. This strain is associated with more severe illness and mortality among the elderly.
Approximately two-thirds of H3N2 viruses characterized by CDC so far this season have not been well matched to the vaccine, meaning that vaccine effectiveness against these viruses may be reduced.
Historically, flu activity peaks in North Carolina around late January or February. However, during the past three seasons, and including this current season, we have seen earlier rises in flu activity.
Important factors to note about this season’s intensity are:
Flu activity has been higher this season than in recent years. Although activity seems to have peaked, flu will still be circulating at high levels in North Carolina over the next several weeks.
We have seen high numbers of deaths among the elderly and outbreaks in long-term care facilities reported this season. This is expected during seasons like this one in which H3N2 is the predominant strain.
Influenza antiviral drugs are an important second line of defense against flu.
These drugs are especially important for people with flu symptoms who are very sick or who are at high risk of serious flu complications (including pregnant women, children 2 years old or younger, people 65 and older, and people with medical conditions such as asthma, diabetes or heart disease). Early antiviral treatment works best.
Yearly flu vaccination remains the first and most important step in protecting against flu.
The flu vaccine protects against three or four strains of flu, depending on which formulation received. Although most of the flu viruses going around this year have not been well-matched to this year’s vaccine, the vaccine also will protect against other strains that could circulate more widely later this season. Also, the flu vaccine may reduce severe outcomes such as hospitalization and death.
Additional guidance and weekly surveillance updates are available at flu.nc.gov.