One of the important hypotheses of vaccination is to make sure that all family members or others who may encounter a newborn child be vaccinated, especially since many vaccinations are not indicated for infants for a couple of months after birth–those newborns are very susceptible to vaccine preventable diseases until they themselves are vaccinated with the DTaP vaccine (which also protects against tetanus and diphtheria).
This protective “cocoon,” especially important with whooping cough (Bordetella pertussis), theoretically blocks the transmission of the disease to a newborn by creating a protective circle of vaccinated individuals around the newborn. A teenage sibling could catch the disease and accidentally infect the infant. Pertussis is bad enough for a teenager, but it can be deadly to a baby.
Even though the evidence for cocooning is growing, there are some flaws to the idea that are still being investigated in various parts of the world. One of the concerns is that asymptomatic carriers of pertussis (who have been vaccinated) might transmit the disease through a cocoon. However, scientists have known that the current version of pertussis vaccine, called acellular pertussis, isn’t as effective as it should be, but it is still better than not vaccinating. Much better. But that is a potential hole in the protective cocoon that needs to be understood better through research.Read More »Why we vaccinate–so mom will protect her newborn baby