In late December 2019, the Wuhan Municipal Health and Health Commission (China) reported the first cases of pneumonia of unknown origin. Today, we know that the origin of this pneumonia was a new virus, SARS-CoV-2, which has caused the great pandemic in which we are immersed and which has caused the death of more than 1.5 million people. people all over the world.
Having a vaccine against SARS-CoV-2 has been a health and social priority from the beginning. Under normal conditions, the development of a vaccine takes an average of 10 years. The race for research into a vaccine to prevent Covid-19 has accelerated to the maximum, and in less than a year the first has already been authorized and some countries have already started or will start in the coming days population vaccination programs.
Vaccines are the best preventive tool we have for the fight against infectious diseases. More than three million deaths are prevented each year worldwide thanks to immunization programs against measles, polio, tetanus, diphtheria and so many other vaccines that have been developed thanks to advances in scientific research. .
According to the latest report from the World Health Organization, on December 10, there are 162 vaccines in preclinical research (animal experimentation) and 52 in clinical phase, of which 12 have already started phase III and two already they have finished. Never before, for any disease, had there been so many candidate vaccines in development and with such a high probability that they would be effective.
In recent weeks, various pharmaceutical companies have reported in press releases excellent efficacy data of the vaccines they are developing. They have just been published in high-level scientific journals, such as The Lancet i The New England Journal of Medicine, the results of the efficacy and safety of phase III clinical trials and the drug regulatory agencies are already completing the evaluation.
This unprecedented race for obtaining and authorizing vaccines against Covid-19 has led many people to ask the following questions: A vaccine for a virus that was identified a year ago? How is that possible? Are we running too much? Will these vaccines be really effective and safe? Am I vaccinated or am I waiting to “see what happens”?
Vaccine development is taking place very quickly because we are experiencing a health emergency. But, and this is very important, all the steps (or phases) established in the methodology of scientific research are being followed. Phase 1 is performed on a small number of healthy volunteers and its goal is to assess safety. In phase 2 the number of people is expanded to a few hundred and the immune response to the vaccine is assessed. In Phase 3, thousands of volunteers are included to study the vaccine’s effectiveness (protection against the disease) and its safety, comparing the results between the group of people who received the vaccine and the placebo group. Once these phases have been passed, the vaccines are evaluated by independent bodies that are responsible for ensuring the safety and efficacy of medicines, such as the European Medicines Agency (EMA) and the Food and Drug Administration. (FDA) of the United States. Authorization procedures by these agencies have been accelerated through a mechanism known as rolling review (continuous review), which is used in health emergency situations. This is an exceptional mechanism by which agencies evaluate the data as it is generated by pharmaceutical companies. Instead of waiting for all phases of clinical trials to be completed, agencies receive the data as they become known, which speeds up the authorization process. The process does not end here, but once the vaccines have been authorized and marketed, phase 4, the post-marketing surveillance phase, is continued, for the long-term continuous monitoring of possible adverse effects that due to their low frequency are not ‘have been able to detect in the previous phases of investigation.
We must not forget the important contribution of the thousands of volunteers who have participated altruistically in the clinical trials to allow each phase to be completed in record time. People who stand in solidarity with the community and who trust science.
Vaccines against SARS-CoV-2 do not come out of nowhere, the knowledge and research conducted with other coronaviruses, such as SARS-CoV-1 or MERS, as well as the use of modern technologies already used in the manufacture of other vaccines have accelerated its development. The use of new manufacturing methods, such as messenger RNA, already used in cancer therapies, is certainly one of the elements that can be a before and after in the manufacture of vaccines against Covid-19 and other diseases. These vaccines induce the manufacture of virus proteins by the cells of the vaccinated person with the consequent production of antibodies, unlike conventional vaccines, which contain part of the virus or its proteins. In addition, an additional advantage of this new technology is the ease and speed of production.
The rapid development of vaccines is undoubtedly a great scientific success that will allow us to finally win the battle against this coronavirus, but there are several questions for which we still have no answers: How long will vaccine protection last? Will protection be high for both mild and severe forms of the disease? Will they protect not only against the disease but also against the infection? Will its effectiveness be similar at all ages? In the coming months we will have answers to some of these questions.