The race to develop a COVID-19 vaccine is in full swing, but most do not know the issues surrounding the development of a vaccine.
Most vaccines have taken decades to develop. There is any one of a number of questions that must be answered before a vaccine can be trusted for use. First, we need to know how to make the vaccine. Currently, there are at least 70 companies trying to develop a vaccine using the five well known methods which have been used in the past. We do not know which method will work the best and produce a vaccine that answers some of the next questions.
These questions involve efficacy and safety. Will the vaccine produce an immune response which is protective and, if so, for how long. Additionally, will the vaccine be safe. We need large populations of treated patients over years of experience to answer this question. The Pneumococcal Vaccine was tested in 30,000 patients over 7 years and the Human Papilloma Vaccine, which prevents cervical cancer, was tested in 30,000 patients over 7 years as well. If a COVID vaccine is made available by fall many of these safety steps will be skipped. Remember, this vaccine will be given to healthy individuals who are otherwise not sick.
The manufacturing of the vaccine must deal with many issues including buffers, stabilizers, vials, and the development of a highly consistent manufacturing process needed for vaccines. Finally, stability and shelf life must be determined before large scale distribution can occur.