As numbers increase, COVID-19 continues to challenge the scientists working to develop an effective vaccine. But what steps are scientists exactly taking to develop safe vaccines? To learn about their efforts, it is important to first understand the interworking of a vaccine, and how your body teaches itself to fight off these invasive viruses.
When foreign microbes enter a human’s body, the immune system will trigger responses to identify and remove them from our body. It is easy to know when the immune system is fighting off these invasions when we notice symptoms such as coughing, sneezing, fevers, and inflammation. B and C cells, known as lymphocytes which compose our adaptive immunity, are effective cells that fight off the invaders in our body, and are trained to recognize them in future cases. Vaccines work by mimicking the disease agents and stimulating the immune system to build defenses against them before the virus spreads. Scientists use vaccines to trigger the immune system, without fully exposing humans to the disease.
Vaccines are made to perform in different ways and for different people. Some versions include, “live” attenuated vaccines which are made from a weaker version of the pathogen, inactive vaccines where pathogens have been killed, to ensure they will not develop into the full disease, and subunit vaccines that are made from a specific part of an antigen, the ingredient that triggers response by isolating specific parts of proteins. The most recent vaccine handled by scientists are DNA vaccines, which isolate the genes that make the antigens the body needs to trigger response to pathogens. Vaccines contain the same or part of the germs that cause the disease, but are weakened so they do not get you sick. What makes them an important medicine is that, unlike curing and treating illnesses, vaccines work to prevent diseases.
The process of creating vaccines, however, is not as easy as it may seem. To begin, scientists must first work to generate the antigens which induce the immune response. Antigens are the part of the pathogen which induces alerts to the immune system, and the pathogens are the microbes themselves that infect the body. This includes the growth and harvesting of the pathogen. Next, the antigens from the cells are released and isolated from the material used to grow it. The goal of this step is to release as much of the virus or bacteria as possible. The third stage is the purification of the antigen. For vaccines that are made from recombinant proteins, this can involve ultrafication and chromatography, a method to separate materials. Finally, scientists may add an adjuvant, a material that nonspecifically enhances immune responses, stabilizers, which prolong shelf life, or preservatives that ensures the safe use of multi-dose vials.
On the frontlines, there are efforts from around the world working on developing a vaccine for Coronavirus. According to the World Health Organization, more than 60 teams of scientists are working to simulate the infection, while avoiding symptoms, in order for the body to destroy the virus if exposed. Under normal circumstances it could take up to 10 years developing a mass produced vaccine, however, with human trials underway, this process is being fast tracked by modern technologies.
Behind the scenes, a Berlin biotech company, JPT Peptide Technologies, is working to create peptide based tools that enable vaccine developers to monitor and track the immune systems of patients. The company assembles peptides, which are amino acid chains that make up proteins, to embody the coronavirus’s most important surface proteins. Some scientists are also focusing on vaccines based on messenger RNA by injecting people with instructions for part of a virus that induces patients to partially produce the virus, encouraging the body to create antibodies. This method is under development and is currently being tested with JPT’s technology, which was formerly used in the fight against Zika Virus and Ebola.
Government and private organizations are taking a number of different approaches. In the United Kingdom, human trials for vaccines are expected to begin the last week in April, as the government launched a task force in efforts to beat the pandemic. Other British scientists from dozens of competing laboratories have joined the race to be the first to develop the vaccine. A team at the Imperial College in London started developing a vaccine in record pace: taking only 14 days to go from a genetic sequencing of the virus, to generating a trial vaccine. In the US, the government has decided in a $1 billion COVID-19 deal with Johnson & Johnson that through an agency under the Department of Health and Human Services they would help finish a product made by Johnson & Johnson’s Janssen division. The vaccine is made from a version of adenovirus 26 (Ad26), which normally induces the common colds, but is modified so it can’t replicate. In the United States, many companies who are initiating developments are receiving funding from two main organizations: the Biomedical Advanced Research and Development Authority, a division of the Department of Health and Human Services, and the National Institute of Allergy and Infectious Diseases, a division of the National Institutes of Health. Others have begun funding trials by themselves, through partnerships, or received funding from Coalition for Epidemic Preparedness Innovations, an organization who has provided millions of dollars in funds for vaccine developers. Repurposing drugs used to fight other viruses is currently one of the fastest ways to treat COVID-19. Scientists are working to develop safe and effective drugs, but they still face challenges of funding, clinical testing, manufacturing proteins, all while expecting new waves of the disease. Although biotech labs have made incredible accomplishments in fast time, experts say the results will not show for at least months.