I'm sorry to disappoint those of you expecting an omicron variant update this week. Although we've seen a lot of commentary in the lay press and some preliminary reports from around the world, in fact we still don't have anything substantive to answer our outstanding questions about transmissibility, disease severity, and immune evasion. Maybe next week.
Home for the Holidays with Flu?
At Children's National for the week ending November 28 we had a slight uptick in influenza cases, though not enough to declare our official start of flu season. CDC surveillance suggests the beginning of increases nationally. Conveniently the CDC published a detailed account of a what has been reported across the country: flu outbreaks on college campuses. The December 3 MMWR report was of an outbreak on the University of Michigan campus occurring in October and November. All the isolates were influenza A H3N2 and should be covered by this year's vaccine. However, H3N2 is a bit more troublesome than other strains in that it is more prone to drift as the season progresses. It is somewhat concerning that individuals with positive and negative tests for flu had similar vaccination rates, suggesting not great protection against mild infection, at least in this one relatively small outbreak. Watch out for spikes in flu following holidays as college students and other travelers add fuel to flu season.
COVID-19 Monoclonal Antibody Use in Young Children?
I was caught completely unaware when I learned on December 3 the FDA extended emergency use authorization down to the newborn period for the monoclonal antibody combination of bamlanivimab and etesevimab for children at high risk of developing COVID-19 complications. Previously this combination had EUA only for high risk individuals 12 years and above with weight at least 40 kg. This extension was based on some new data from an open-label (i.e. no control arm) trial looking at treatment effects on viral load as well as some pharmacokinetic data on weight-based dosing for younger age groups. The EUA covers both therapeutic and post-exposure indications. Note also that, for children above age 2 years of age, this is only for outpatient use.
I have one main concern about this EUA related to use in children in the first year of life. First, the notice lists age < 1 year as defining a high risk group, without need for any other risk factors. To my knowledge no study has found this age group to represent high risk for COVID-19 complications. Second, the youngest child in the trial was 10 months and weighed 8.6 kg; only 5 children in the trial were less than 2 years of age. We know that metabolism in newborns and young infants is very different from older children and, coupled with the fact that I can't find evidence that otherwise healthy young infants represent a high risk group, I'm reluctant to sign on to use in otherwise healthy children in the first year of life. Our team at Children's National is looking at the data and will come up with guidelines incorporating this new EUA.