The whooping cough vaccine may shrink in effectiveness because the bacteria are mutated, warns the Centers for Disease Control and Prevention (CDC).
Researchers looked at laboratory samples from patients who had the infection between 2000 and 2013.
They discovered that the bacterium that causes the disease, Bordetella pertussis, underwent genetic changes in the last decade.
This means that the currently available vaccine corresponds to an & # 39; older version & # 39; of the disease, NBC News reported.
Although the team insists that the vaccine still offers the best protection against the condition, they hope that the findings, published in the journal Emerging Infectious Diseases, help researchers develop a better and more effective vaccine.
Researchers at the CDC say that the bacterium that causes whooping cough, Bordetella pertussis, has undergone genetic changes in the last decade (file image)
Whooping cough is commonly reported in single cases. However, several states have reported outbreaks throughout the school this year.
The Los Angeles Times reported that 30 students at the prestigious Harvard-Westlake School fell ill from whooping cough, part of a larger outbreak of 50 cases in the LA area.
And, just 100 miles south, officials in San Diego County have confirmed at least 70 cases of pertussis, according to KGTV.
At least 36 cases have now been confirmed, especially in young children, in school districts in South Dakota.
Whooping cough, also known as pertussis, is a respiratory tract infection that is highly contagious.
When someone coughs, sneezes or talks, contaminated drops are injected into the air where other people can breathe them in and then get infected.
In severe cases, patients experience cough showers that end with a & # 39; whoop & # 39; sound when a breath is taken.
The first symptoms usually resemble those of a cold or flu, including cough, runny nose and fever.
However, after one to two weeks, patients experience severe coughing through mucus that blocks the airways, which can last up to 100 days.
The best protection against whooping cough comes from the DTaP vaccine, which also protects against diphtheria and tetanus.
It is given as a series at two months, four months, six months, 15 to 18 months, and then four to six years.
The CDC recommends that children between 11 and 12 years old receive a booster with a similar vaccine called Tdap.
Prior to the introduction of the vaccine in the 1940s, approximately 200,000 children each year had whooping cough, with around 90,000 people dying.
According to the latest figures from the CDC, nearly 13,500 cases were reported in 2018 with around 10 deaths.
But even after a child has received all five doses, the DTaP and Tdap vaccines are between 80 and 90 percent effective, lower than the percentages for other vaccine-preventable diseases.
Therefore, the concept of & # 39; herd immunity & # 39; as important when it comes to preventing the spread of whooping cough.
& # 39; Herd immunity & # 39; occurs when the vast majority of a community – between 80 and 95 percent – becomes immune, so that if a disease is introduced, it cannot spread.
That is why those who cannot be vaccinated, including the sick, very young and old, are protected.
& # 39; The whooping cough vaccine is not optimal & # 39 ;, Dr. William Schaffner, professor of preventive medicine at Vanderbilt University Medical Center in Nashville, Tennessee, told NBC News.
& # 39; We make the best use of the vaccine, while we do fervent research to make a better vaccine. & # 39;
The new report comes as the US fights an outbreak of another highly contagious childhood disease: measles. Since the beginning of 2019, the CDC has confirmed 228 cases in 12 states.
Federal health officials say the spread of misinformation online about vaccines is to blame for the outbreaks.