Influenza Update — 2021-22 (3)

 

For the second year in a row it has been a relatively quiet influenza season throughout the United States. Thanks to face mask mandates, options for working at home, travel restrictions, and other factors related to preventing the spread of SARS-CoV-2, the influenza virus has found it hard to find enough vulnerable hosts to wreak its typical annual havoc. As the biphasic pattern on the chart above indicates, the relaxation of those COVID-19 restrictions over the last couple of months has resulted in an unusual second wave of seasonal influenza infections throughout the country. Influenza activity is significantly higher than it was when The PediaBlog took a peek in February.

Influenza activity varies by region. Activity is highest in the northeast, south-central and mountain regions of the country.

— CDC Weekly U.S. Influenza Surveillance Report for Week 15, ending April 16, 2022.

 

 

The good news is that hospitalizations and deaths from influenza remain below the baseline for the second consecutive year. However, the number of hospitalizations due to influenza has actually increased each week for the last 11 weeks, according to CDC’s FluView. A spike of new cases and hospitalizations so late in the season is very unusual.

Other key points to know as influenza prepares to bid farewell for the summer:

• CDC estimates that so far this season, there have been at least 4.7 million flu illnesses, 47,000 hospitalizations, and 2,800 deaths from flu.

• Three pediatric deaths associated with influenza were reported in Week 15. Overall, there have been 22 pediatric deaths this season, which is way below what we usually see by the end of a flu season.

 

As you can gather from glancing at the chart at the top, almost all the cases that have been identified this season came from infection with the influenza A(H3N2) strain. Very few are caused by influenza B strains. One reason might be that the influenza A(H3N2) strain that circulating around the U.S. is antigenically very different from the A(H3N2) strain included in this year’s influenza vaccine. By contrast, both influenza B strains included in the vaccine (B/Victoria and B/Yamagata) are well matched to the circulating B strains.

Alyssa Lukpat highlights the vaccine’s “lackluster” performance against the dominant variety of influenza this year:

This season’s flu vaccine has offered little to no protection against getting a mild or moderate case of influenza, the Centers for Disease Control and Prevention said this week.

The vaccine was only about 16 percent effective at reducing a person’s chance of getting a mild or moderate infection, the agency said. Experts said a good rate would be at least 50 percent.

 

According to the CDC’s analysis of the vaccines’ effectiveness, even a weak vaccine offers some protection against severe bouts of influenza. Expecting future vaccines to be better matched, Melissa Jenco says the American Academy of Pediatrics will continue to strongly recommend annual flu vaccines for every child aged 6 months and older:

“Kids experience really substantial morbidity from flu, including hospitalization and death,” said Kristina Bryant, M.D., FAAP, influenza lead for the AAP Committee on Infectious Diseases. “We also know that children play a key role in the transmission of flu within households and within the community, so it remains really important for children 6 months and older to be immunized.”

The AAP recommendations include the following:

• Children 6 months and older should be vaccinated.

• Any licensed influenza vaccine appropriate by age and health status can be used.

• The AAP does not prefer any product over another for children and adolescents with no contraindications.

• Children who are eligible for both a flu and COVID-19 vaccine can receive them at the same visit.

 

Track every flu season on CDC’s FluView here.

 

source http://www.thepediablog.com/2022/04/25/influenza-update-2021-22-3/