SEVERE WX : Fire Weather Watch View Alerts
STREAMING NOW: Watch Now

This year's flu shot is less than 50% effective in preventing infection, CDC says

Don't let your guard down: The US flu season is expected to continue for several more weeks, with activity across the nation now elevated, the US Centers for...

Posted: Feb 14, 2019 11:55 AM

Don't let your guard down: The US flu season is expected to continue for several more weeks, with activity across the nation now elevated, the US Centers for Disease Control and Prevention reported Thursday. A flu shot is still recommended for those who have neglected to get one, but the CDC estimated this year's vaccine's overall effectiveness in preventing an infection at just 47%.

The shot's success varies based on your age, the CDC noted. Among children up to 17, its overall effectiveness against flu was 61%, while just 24% of adults 50 and older who received the shot gained protection against infection.

Studies show that vaccination reduces the risk of influenza-related deaths in children; 80% of the children in the United States who died from flu last season were unvaccinated. Additionally, the shot "prevents a substantial number of influenza-related illnesses, hospitalizations, and deaths annually," noted the authors of the new CDC report.

Dr. William Schaffner, medical director of the nonprofit National Foundation for Infectious Diseases, said that those who get flu after receiving vaccine are less likely to require hospitalization and are less likely to die of the illness.

"The vaccine is not perfect," Schaffner said. "But give the vaccine credit for softening the blow."

The virus' severity this season compared with last has been low, with a smaller percentage of doctor's office visits, lower rates of hospitalization and fewer deaths through February 2, the CDC reports. The official start of the season was September 30; activity remained low during October and November, increased in late December and then remained elevated through early February.

Twenty-eight children have died of flu-related complications this season as of February 2, the CDC noted.

"Fingers crossed that we're now heading toward the bottom part of the season," said Richard Webby, a flu scientist and adviser to the World Health Organization on recommendations for the composition of flu vaccines. "Overall, it's been a relatively mild season, and compared to last year, it's a bit of a welcome reprieve."

The reason for that is that milder H1N1 strains of the influenza virus have dominated in most of the country, with H3N2, a strain that causes more severe illness that ran rampant last winter, predominating in southeastern areas.

In recent weeks, though, the proportion of illness due to H3N2 has grown in several regions.

Last winter was the deadliest US flu season in more than four decades. An estimated 80,000 Americans, including 180 children, died of flu and its complications, the CDC reported. Additionally, the nation experienced an estimated 900,000 hospitalizations, a record, during the last season.

Overall, the effectiveness of the seasonal flu vaccine for last season was estimated to be 40%. This means the vaccine reduced a person's risk of having to seek medical care by 40%, the CDC found. Yet, among children, the shot was estimated to be 59% effective.

Despite the fact that the strains circulating this winter are aligned with the viruses used to make the vaccine, the manufacturing process tends to cause slight changes that create a mismatch, Webby explained. This season's flu shot is "clearly not where we want it to be, but it has been superior overall than the past few seasons," he said.

The CDC also recommends antiviral medication for people "with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for influenza complications."

In October, the US Food and Drug Administration approved a new antiviral, baloxavir marboxil or Xofluza, a single-dose oral prescription drug. The pill is intended for patients 12 or older who have had symptoms for no more than 48 hours.

The antiviral is the first flu treatment approved by the FDA in nearly 20 years. During past seasons, Tamiflu has been the antiviral medication prescribed for many people.

When patients with the flu are treated within 48 hours of becoming sick, antiviral drugs can reduce symptoms and duration of illness, according to the FDA. There are side effects for both drugs, including diarrhea, bronchitis, headache and nausea for Xofluza and nausea, vomiting, diarrhea and headache for Tamiflu.

Finally, the CDC recommends practicing common-sense methods of preventing the spread of flu. Wash your hands thoroughly, and avoid close contact with those who are sick. If you feel yourself becoming sick, remember to cover your mouth and nose when coughing and sneezing, and if you are sick, stay home if possible.

California Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 333357

Reported Deaths: 7089
CountyConfirmedDeaths
Los Angeles1363573824
Riverside25748550
Orange25255424
San Diego19929422
San Bernardino19502307
Fresno828288
Imperial7977136
Alameda7976148
San Joaquin698870
Kern660198
Santa Clara6542167
Tulare5942152
Sacramento571483
Stanislaus497351
Contra Costa485290
San Francisco459050
Ventura424653
San Mateo4045112
Santa Barbara393131
Marin370232
Kings297039
Monterey279018
Solano207528
Merced188412
Sonoma181916
Placer111411
San Luis Obispo10065
Yolo92928
Madera8938
Santa Cruz5693
Napa5184
Lassen4280
Sutter4034
San Benito3622
Butte3384
El Dorado3070
Shasta2006
Yuba1983
Glenn1760
Humboldt1654
Nevada1631
Mendocino1320
Lake1211
Colusa1130
Tehama1071
Tuolumne730
Calaveras670
Del Norte610
Mono521
Siskiyou410
Amador400
Inyo351
Mariposa321
Plumas190
Alpine20
Trinity20
Sierra10
Unassigned00
Chico
Few Clouds
91° wxIcon
Hi: 99° Lo: 65°
Feels Like: 91°
Oroville
Clear
94° wxIcon
Hi: 100° Lo: 66°
Feels Like: 94°
Paradise
Few Clouds
91° wxIcon
Hi: 92° Lo: 68°
Feels Like: 91°
Chester
Clear
88° wxIcon
Hi: 86° Lo: 60°
Feels Like: 88°
Red Bluff
Clear
99° wxIcon
Hi: 102° Lo: 69°
Feels Like: 99°
Willows
Few Clouds
91° wxIcon
Hi: 102° Lo: 62°
Feels Like: 91°
We're getting hotter as we head into the middle of this week, and the potential for thunderstorms will prompt a Fire Weather Watch in the Sierra on Thursday. Hot & dry conditions continue through your weekend.
KHSL Severe
KHSL Radar
KHSL Temperatures

Community Events