The flu vaccine was again a big disappointment.
The vaccine did not work against influenza that occurred in the middle of the previous flu season and lowered overall efficacy to 29 percent. Disease control and prevention reported on Thursday.
The flu vaccine worked well at the beginning of the season and its efficacy was 47 percent in February. During a second wave, driven by a harder line, it was practically worthless at only 9 percent.
There was "no significant protection" against this strain, CDC Brendan Flannery said.
Flu Vaccines Are Made Every Year Up Protect yourself against three or four different types of flu viruses. The ingredients are based on predictions about which strains will make people ill the following winter.
The recording of this season proved to be a mismatch with the mistake that occurred late.
This led to a deterioration in the overall efficiency lowest in recent years. Since 201
Vaccines against some other infectious diseases are considered unsuccessful unless they are at least 90 percent effective. However, the flu is a special challenge, in part because the virus can change so fast. Overall, the average flu shot is 40 percent.
Flu vaccines are recommended for virtually all Americans who are 6 months or older. The vaccine is still worth it, according to official figures, as it works against some strains and is likely to prevent 40,000 to 90,000 hospital admissions in the winter flu season.
The effectiveness of the vaccine is based on preventing cases so bad that someone can be sent to the doctor] FOLLOW NBC HEALTH TWITTER & FACEBOOK