CDC Infographic on how vaccines are developed, licensed and safety tested/monitored.
Thanks for the graphic.
It is interesting how phase one and two typically involve smaller numbers.
I found this article on the different phases of testing, and it says that phase 1 and 2 are most often concerned with safety, while phase 3 is more concerned with efficacy. It is a little frightening that safety (which is a big deal to many people) are dominant in phase 1 and 2, which tend to be smaller, while efficacy is dominant in the larger phase.
"Typically the primary objective of a Phase III trial is to estimate efficacy of a candidate vaccine in the population of interest. Like Phase II trials, efficacy trials are usually randomized, double-blind, and placebo-controlled. The ability to randomize partici- pants to a placebo group is dictated by ethical considerations; in particular, whether or not an efficacious vaccine already exists. Unless otherwise specified, we assume a two- arm trial with one arm randomized to the vaccine of interest and the other arm randomized to placebo (typically a vaccine for another disease)….."
Surely you want to lower the risk when you're really unsure of the safety - so starting small makes sense.
And while phase 3 is mainly for efficacy, I'm sure they collect data on reactions at the same time.
I don't really understand the problem you have with it to be honest.
I would like more safety testing done at stage 3, when a larger population is tested. I am not sure the smaller studies of phase 1 and 2 are enough to satisfy that it is safe.
I am not in love with how they worded phase 3 in the infographic. CDC said:
1. How do people who get the vaccine compare to people who do not get the vaccine?
2. Is the vaccine safe
3. is the vaccine effective
4. what are the most common side effects
As I understand it, phase 3 mostly looks at efficacy, where as 2 or 3 of the 4 points above focus more on safety. It seems a little misleading.
I thought the rest of infographic was fine.
I also do not think many parents realise that most testing is done by the people who will ultimately sell the product - i.e the pharmaceutical companies. That would have been an important point to make in a parental education document.
Edited by kathymuggle - 1/26/13 at 10:49am