MarketplaceFlu

Actions

The flu vaccine is only 10 percent effective this year

Posted
and last updated

The first data on how well the flu vaccine is working this season in North America has just been published.

The main flu subtype going around in the U.S. and Canada this season is H3N2. A recent study from the journal Eurosurveillance, Europe's journal on infectious disease surveillance, found that the vaccine in use this season is only 10 percent effective.

To produce flu vaccines, manufacturers must grow flu viruses. Researchers discovered long ago that a flu virus grows extremely effectively in eggs. However, researchers also found that there are problems with the egg-based approach that specifically relate to H3N2, and those issues are contributing to lower efficacy this season.

Download
Supplement 1: GISAID sequences used in the study

,

Weather

Daily Forecast

View Hourly Forecast

Day

Conditions

HI / LO

Precip

Thursday

05/01/2025

Thunderstorms Early

-° / 61°

55%

Friday

05/02/2025

Partly Cloudy

89° / 60°

0%

Saturday

05/03/2025

Cloudy

76° / 52°

24%

Sunday

05/04/2025

Partly Cloudy

68° / 56°

3%

Monday

05/05/2025

Clear

81° / 59°

2%

Tuesday

05/06/2025

Clear

86° / 60°

1%

Wednesday

05/07/2025

Clear

88° / 63°

1%

Thursday

05/08/2025

Clear

90° / 65°

2%