In January, Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, stated that it would take twelve to eighteen months to develop a Coronavirus vaccine. As of early August, there are more than 165 COVID-19 vaccines being developed according to WHO’s landscape documents; six of which are in Phase III trials. With scientists across the globe racing to develop an effective vaccine, the typical research and testing process is being acutely compressed, raising concerns about the safety of their prospective products.
The development cycle of a vaccine usually lasts for more than ten years, with our current record at four years. For instance, the varicella (chickenpox) vaccine and the rotavirus vaccine took 28 years and 15 years respectively. A complete cycle entails various stages, spanning from academic research, pre-clinical work, Phase I to Phase III trials, factory-building, manufacturing, to eventually approval and distribution. Some steps may take up to nearly four years. However, this strenuous process is advancing at an unprecedented speed for coronavirus vaccines, as the pandemic’s devastating effect swept across the globe. So far, it has resulted in almost 18.8 million confirmed cases and more than 706,000 deaths. A vaccine will be the ultimate weapon against the deadly virus and the best route back to normal life.
Many researchers are shortening the process by combining phases and rushing to test on more people without due confirmation. Luckily, since numerous studies had been made on other coronaviruses that caused outbreaks in the past, such as SARS and MERS, scientists are getting a head start on academic research. SARS-CoV-2, the virus that causes COVID-19, closely resembles SARS. Both have a spike-like structure called an S protein that attaches to the surface of cells in human lungs. An effective vaccine would prevent the protein from binding to human cells and stop the virus from reproducing.
As for now, there are three common approaches taken by labs across the world to produce a COVID-19 vaccine. Live vaccines introduce a weakened form of the virus to subjects and prompt an immune response without infecting them. However, this traditional approach requires extensive safety testing, which results in a slower development process.
The second conventional pathway is inactivated vaccines, which utilize a dead version of the virus. Concerns have been raised about their effectiveness, as inactivated vaccines may not provide adequate and long-termed protection.
The newest option is genetically engineered vaccines, or gene-based vaccines. Most companies and institutes are developing them due to their shorter manufacturing times and potentially great effectiveness. Gene-based vaccines employ experimental RNA and DNA technology, which provides the body with instructions for making copies of the S protein and causing an immune response in turn. Scientists claim that once developed, gene-based vaccines are faster and cheaper to produce and safer for the patients. However, this approach is novel and has never been licensed for human use.
With many uncertainties looming ahead, the path to a fully developed and approved coronavirus vaccine may be longer than expected. As such, it is crucial that we do not rely excessively on the prospect of a vaccine against COVID-19. The best that we as individuals can do is strictly follow official guidelines—stay home whenever possible, and wear face masks when necessary. As Mark Woolhouse, a leading epidemiologist, told The Guardian: “A vaccine is a hope, not a strategy.”