The Global Forum on Research and Innovation opened in Geneva on Feb. 11, with World Health Organization Director-General Desmond Tansey saying a vaccine for the novel coronavirus (COVID-2019) could be ready in 18 months. Why does it take so long to produce the vaccine? Will we not be able to prevent the spread of the novel coronavirus in these 18 months without a vaccine? The Global Forum on Research and Innovation opened in Geneva on February 11, with the Director-General of the World Health Organization, Desmond Tan, saying that a vaccine for the novel coronavirus (COVID-2019) could be ready in 18 months. Many people became anxious when they learned this news and wondered why it took so long to produce the vaccine. Does the absence of the vaccine for 18 months mean that we cannot prevent the spread of the novel coronavirus? In order to eliminate the doubts and anxieties in our patients’ minds, let’s start with our conclusion directly. First of all, 18 months can be considered a miracle for vaccine development, and even if the vaccine is not developed soon, we have ways to deal with it. 1.Vaccine preparation process Why 18 months is already a godsend? First of all, let’s understand what is a vaccine and how to prepare it. Vaccines are biological preparations made from various types of pathogenic microorganisms for vaccination, and can be divided into two types of live and dead vaccines. The principle of the vaccine, in layman’s terms, is equivalent to our body’s immune system and pathogens, and the vaccine is equivalent to an enemy army that we first turn against. In the absence of this enemy army (without the vaccine), the pathogens may start to act in our body after breaking through our walls and guards (non-specific immunity), when the special forces in our body (specific immunity) fail to respond. And after we have turned an enemy army and mastered their characteristics, the special forces in our body are equivalent to receiving the news in advance to the training, and can react quickly to destroy the pathogens quickly when the enemy army arrives. And to get a qualified virus vaccine is not so simple, first need to extract the virus from the infected person or animal, and this extracted virus strains or to have good antigenicity, have a strong viability. The virus obtained at this time is called wild strain, and the toxicity of wild strain is still too strong, so then we need to culture it with chicken embryo, cells, etc. to continuously pass it on, select the less toxic attenuated strain, of which a large number of cultures, and then extract the virus solution for purification, inactivation, identification and a series of steps to make the virus vaccine stock solution. The stock solution is diluted as needed, and certain adjuvants are added, etc., to obtain a vaccine for preclinical evaluation. After that, researchers need to start a series of physicochemical and biological tests on it to make sure it meets the design requirements, and then start the safety and efficacy studies on animals. 2. Clinical trial stage After all the above tests are completed, there is a long clinical trial waiting. Phase I clinical trials are generally conducted in healthy subjects to evaluate the safety of the vaccine; Phase II clinical trials are the preliminary evaluation stage of therapeutic effects, which is the initial evaluation of the therapeutic effects and safety of the drug for patients with target indications, and also includes providing the basis for the study design of Phase III clinical trials and the determination of the dosing scheme; Phase III Phase III clinical trial is the stage of confirming the therapeutic effect, which is to further verify the therapeutic effect and safety of the drug for patients with target indications and evaluate the benefit-risk relationship. After approval for marketing, further studies are still needed to examine the efficacy and adverse effects under extensive conditions of use. The post-marketing studies are known as “Phase IV clinical trials” in most countries internationally.