In vaccine research, the Phase III section, is the last section but the longest in time involved, before the vaccine is released for manufacturing and then public vaccine injections.
In the most recent, COVID 19 research some companies are in this phase III, which involves about 30,000 participants and can go on for several years to determine safety and efficacy.
Recently, there has been some speculation about problems due to reports that one company Astra Zeneca has had several “pauses” or stops during this testing phase.
During such a long phase of testing, it is likely that some participants will develop health issues. This may or may not come from the vaccine being tested.
How and Why Do They Decide to Pause in Vaccine Testing?
5. Phase III is Double-Blind Studies
Most of these tests are “double-blind” tested, meaning ½ of participants are getting the real vaccine the other ½ are getting a placebo, usually saline. No doctor or participant knows who has which shot. Only external monitoring boards have the list of participants and what they received. The main goal in this phase, is to show the vaccine has lower rates of actual infections than those who did not receive the vaccines shot.
4. Vaccines and the CDC
Dr. Robert Redfield, Director of the US Center for Disease Control and Prevention (CDC), implied that it is a common event to pause or temporarily stop Phase III studies. But other vaccine experts interviewed by CNN say it is not common practice!
3. Why Do You Pause a Study?
If a participant becomes sick, they need to determine if it is related to the vaccine or to external influences. And the monitoring board needs to review where this illness came from.
2. Adverse Reactions in Vaccine Research
This COVID 19 vaccine research has been paused two times for adverse reactions, which is very rare. In the 1st case, they determined the participant was an undiagnosed case of Multiple Sclerosis (MS). Then the 2nd pause was when a participant was found to have transverse myelitis, an inflammation of the spinal cord.
Now the question is was it the Vaccine?
1. How do They Decide if a Pause is Necessary?
Well, something like a headache, slight fever, or minor pains are not considered worrisome, this is part of natural daily life. But when pain is intense or sickness is sudden, like major muscle or Central Nervous System (CNS) complaints or even life threatening; and if it happens to several study participants, this could be vaccine-related.
If they have several complaints that are similar in diagnosis, it could very likely be something in the vaccine either the virus itself or one of the adjuvants (additives) used to help vaccine react with the immune system.
At this time, they have to make a decision to continue Phase III, suggest a change in vaccine or maybe how it may be administered, or to shut down the study itself since it may affect to many participants in the study.
In the end it means going back to the drawing board to reconfigure how to change or adjust the vaccine so there are no or at least, fewer adverse reactions. There are always a percentage of reactions to vaccines but their goal is to keep the numbers affected at a minimum.