Vaccine development does not happen with the snap of a finger. Historically, it takes years, sometimes decades, to develop an effective vaccine, and even then, several years of testing and clinical trials are necessary to confirm its safety. There is a rush, however, to develop a vaccine for the novel coronavirus which has infected over 37 million, and killed over 1 million individuals as of October 10, 2020 (World-O-Meter). In fact, there are currently over one hundred vaccines under development around the world. But before we can effectively subdue this virus, there are important hurdles to overcome and questions to answer about the effects and potential risks of the vaccine candidates.
A vaccine contains the same microbes that cause the target disease, but only those which have either been killed or weakened to the point where it cannot induce the actual illness. Instead, the vaccine stimulates the patient’s immune system to produce antibodies, providing immunity against the disease without the patients suffering the symptoms. One way that scientists can inactivate viruses in particular is to target viral proteins. The novel coronavirus, SARS-CoV-2, is an enveloped virus with single-stranded RNA containing S, E, M and N genes that encode proteins. In the process of vaccine development, researchers have been targeting the S protein, as it seems to induce the production of neutralizing antibodies and a strong T cell response in the body’s immune system. (Al-Kassmy et al., 2020).
The process of COVID-19 vaccine development is moving at a faster pace than any vaccine in the past. Usually, it takes eight to fifteen years to develop a vaccine, but some COVID vaccines are already in phase III clinical trials. Indeed, new manufacturing platforms, structure-based antigen design, computational biology, protein engineering, and gene synthesis have all greatly enhanced the speed and precision of vaccine development (Graham, 2020). Scientists and pharmaceutical companies, for the most part, have been focusing on creating a nucleic acid vaccine, though a range of other vaccine types exist in the form of virus-like particles, peptides, viral vectors, recombinant proteins, live attenuated viruses, and inactivated viruses. The nucleic acid vaccines, in particular, work by stimulating the immune system to produce antibodies from protein antigens coded from gene sequences in the virus. Moderna, one of the pharmaceutical companies, developed an mRNA vaccine dubbed mRNA1273, and began its clinical testing only two months after identifying the gene sequence of the coronavirus (Le et al., 2020). In the phase I clinical trial with 45 healthy adults, the results were an anti SARS-CoV-2 immune response in all participants, therefore showing that the body was defending itself against the virus with no short-term safety concerns (Al-Kassmy et al., 2020). As promising as these preliminary results seem to be, nucleic acid vaccines tend to have a high failure rate in clinical trials, which explains why there are no RNA or DNA based vaccines licensed to date (Shin et al., 2020).
But the pressure to produce an effective vaccine rapidly raises serious safety concerns. In order to minimize risks, researchers created animal models specifically for COVID-19 clinical trial testing including ACE2-transgenic mice, hamsters, ferrets and non-human primates (Le et al., 2020). ACE2-transgenic mice are mice transplanted with human immune by inserting a vector containing a human ACE2-coding sequence, which was observed in the initially infected airway epithelial cells. This allows researchers to better understand how the disease might behave in the human body. For example, researchers found, through testing on mice, that vaccinating via the nose creates a very strong immune response; however clinical trials on animals cannot substitute for clinical trials with humans.
Scientists are still researching to answer the many questions that people have about the coronavirus, the vaccine, and the risks that it proposes. In a poll by the Pew Research Center, more than ⅓ of Americans have indicated that they would not get the coronavirus vaccine when one becomes available, as they do not feel confident with the information that they have (Felter 2020). Although the rush for a COVID-19 vaccine is necessary as the number of people infected can double or triple in a matter of days, it is still important to take enough time in order to produce a safe, distributable vaccine that most of the population is comfortable taking.
Another challenge is the global need for a vaccine. In order to manufacture billions of doses, the entire world needs to be in cooperation. The negotiation of cost, global distribution systems, and the requirements enforced by different countries are all constriction points in the delivery of vaccines to individuals and communities all around the world (Corey et al., 2020,).
Vaccines are medical miracles and after the social and economic devastation caused by the ongoing COVID-19 pandemic, the entire globe is hoping for another medical miracle to stop the spread. What resulted in an understandable rush towards vaccine development, but we have to be cognizant that there could be harmful risks involved. Caution must be observed, clinical trials must be carried out, and animal testing must occur before we test on humans. There are rules and regulations to follow every step of the way in order to develop a safe and effective vaccine that one hundred percent of Americans will feel comfortable receiving.
Edited by Sarah Kim
Placed by Rachel Xue
Al-Kassmy, J., Pedersen, J., & Kobinger, G. (2020). Vaccine Candidates against Coronavirus Infections. Where Does COVID-19 Stand? Viruses, 12(8), 861. https://doi.org/10.3390/v12080861
Corey, L., Mascola, J. R., Fauci, A. S., & Collins, F. S. (2020). A strategic approach to COVID-19 vaccine R&D. Science, 368(6494), 948–950. https://doi.org/10.1126/science.abc5312
Graham, B. S. (2020). Rapid COVID-19 vaccine development. Science, 368(6494), 945–946. https://doi.org/10.1126/science.abb8923
Haseltine, W. A. H. (2020, June 22). The Risks of Rushing a COVID-19 Vaccine. Scientific American. https://www.scientificamerican.com/article/the-risks-of-rushing-a-covid-19-vaccine/
Hickock, K. H. (2020, June 1). Who Created the Polio Vaccine? Live Science. https://www.livescience.com/polio-virus-vaccine.html
Le, T. T. L., Andreadakis, A. Z., Roman, R. G. R., Tollefsen, S. F., Saville, M. S., & Mayhew, S. M. (2020). COVID-19 therapies and vaccine landscape. Nature Materials, 19(8), 809. https://doi.org/10.1038/s41563-020-0758-9
Shin, M. D., Shukla, S., Chung, Y. H., Beiss, V., Chan, S. K., Ortega-Rivera, O. A., Wirth, D. M., Chen, A., Sack, M., Pokorski, J. K., & Steinmetz, N. F. (2020). COVID-19 vaccine development and a potential nanomaterial path forward. Nature Nanotechnology, 15(8), 646–655. https://doi.org/10.1038/s41565-020-0737-y
Stern, A. M. S. (2005, June). The History Of Vaccines And Immunization: Familiar Patterns, New Challenges. Health Affairs. https://www.healthaffairs.org/doi/full/10.1377/hlthaff.24.3.611
Claire Felter, C. F. (2020, October 1). The Vaccine Production Process [Illustration]. What Is the World Doing to Create a COVID-19 Vaccine? https://www.cfr.org/backgrounder/what-world-doing-create-covid-19-vaccine
Cuiling Zhang, C. Z., Giulietta Maruggi, G. M., Hu Shan, H. S., & Junwei Li, J. L. (2019, June 27). Figure 1. The mechanisms of different nucleic acid vaccines, including DNA vaccines, mRNA vaccines. MHC, Major histocompatibility complex. [Illustration]. Advances in MRNA Vaccines for Infectious Diseases. https://www.frontiersin.org/articles/10.3389/fimmu.2019.00594/full