Protection of the TDAP vaccine does not last long
When my patient is examined for 11 years, I will give them a TDAP vaccine. I explain to them that a large part of the reason we will give is to protect them against pertussis or whooping cough. I will talk about the outbreak that is always happening, why it is dangerous for small babies, and how to prevent this vaccine from catching pertussis and spread it to others.
In the early 1990's, different types of pertussis vaccine, "whole cell" vaccine was used. Among the vaccinated people, it worked pretty well and the proportion of whooping cough was quite low. However, the vaccine had side effects. Fever, swelling, pain, drowsiness and hypersensitivity at the injection site were common. In rare cases it has rarely caused seizures or similar episodes, rarely causing acute encephalopathy that is critical but temporary affecting the brain.
For this reason, we changed the vaccine to "cell-free" with few side effects. We went from DTP to DTaP. As we arrived, the protection of children stopped just as before. Recent studies have shown that protection against pertussis is reduced by 42% annually after the fifth vaccination, 4-6 years later. This means that there is little protection until children reach 10 or 11 years old.
Pertussis caught in California when there were about 10 children in the first group who got only DTaP instead of DTP in 2010. Clearly it was necessary to strengthen protection. California state required TDAP (a version of DTaP given to elderly children and adults) at junior high school, but it helped for a while, but in 2014 there was another epidemic.
People who obtained it in 2010 or 2011 by 2014 are no longer protected.
Researchers could truly appreciate all of these data and understand that its effectiveness is about 70% in the first year after TDAP. After four years, its protection is less than 10%. Given that the most common sources of infection for infants are siblings, this is a real problem.
Obviously, if the point of vaccination is to protect from disease, we need to do something different.
We have two choices. The first and best way is to make a better vaccine. We may need to consider returning to the whole cell pertussis vaccine and finding ways to prevent or cope with side effects. However, it would be obviously better if we could make a whole cell vaccine without many side effects. Researchers are working on this, but they can not be seen for years.
Another option is to use the TdaP vaccine more intelligently. Instead of vaccinating everyone with 11 or 12, a better approach is to use it according to known or likely outbreaks. Just like vaccinating pregnant women during pregnancy, which is very effective in protecting infants, we may not want to give anyone anything, and would like to use the vaccine in specific people and circumstances I do not.
It is difficult to organize and execute. It must be in the middle of all outbreaks or exposure. It requires a lot of public education and outreach, not a daily examination, but family members are responsible and must receive vaccination as necessary. But if that is necessary to protect neonates and other vulnerable people from pertussis, that is what we have to do.
Ultimately, vaccination has always been to protect everyone around you, not just your child.
No comments:
Post a Comment