Research says that children whose childhood vaccinations were skipped or delayed contribute to the number of pertussis and measles outbreaks in the United States.
Measles had been eliminated in the US. in 2000. However, there are still 1,416 measles cases reported and more than 50 percent of the patients were found no history of measles vaccination.
Around 25-45 percent of people from the five largest statewide epidemics since 1977 who are among more than 10,000 pertussis patients with known vaccination status were unvaccinated or just partially vaccinated, Reuters reported.
"If there are a high number of susceptible or unvaccinated individuals in the community the risk of getting infected - even for vaccinated children - goes up," said Dr. Saad Omer, senior study author and a pediatrics and epidemiology researcher at Emory University in Atlanta. "That's because few vaccines are 100 percent effective," Omer added via email.
According to the US Centers for Disease Control and Prevention, up to two percent of people who have all the five recommended vaccine doses may still get pertussis or whopping cough. Around three percent of people with complete measles vaccine may still get infected.
Some states are becoming strict with regards to their law on who can skip childhood vaccines and why. States require the children to be vaccinated for them to be able to go to a public school, according to NBC News. Some studies have shown that the more lenient a state is, the more likely the parents to get a reason to skip childhood vaccination.
It also shows that Mississippi has higher rates of vaccination since they only allow medical exemptions for vaccines compared to Colorado which has a more lenient law. South Dakota, Vermont, Illinois, West Virginia and Connecticut have all passed legislation last year to tighten their requirements, as stated by the National Conference of State Legislatures.
"Parents hesitant to vaccinate their children may delay routine immunizations or seek exemptions from state vaccine mandates. Recent outbreaks of vaccine-preventable diseases in the United States have drawn attention to this phenomenon," Omer's team wrote.
