The COVID-19 pandemic rages on in the United States and all over the world. Although doctors are improving their ability to treat the disease, over 1,000 people have been dying daily in the U.S. for the past several days. The U.S. has over 150,000 deaths, representing almost one-fourth of the world’s mortality from the virus.
The best hope to get the pandemic under control in the long term, or to end it entirely, is to develop a vaccine. Currently, there is no available vaccine. The race is on, worldwide, to develop a vaccine. As of now there are 157 vaccines in development globally.
Coronavirus vaccine research
Coronaviruses are common viruses that cause illnesses ranging from the common cold to severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and COVID-19. COVID-19 is closely related to the SARS coronavirus. Resultantly, researchers named the new virus (COVID-19) SARS-CoV-2.
Researchers are attempting to develop a COVID-19 vaccine at a speed not yet seen before. One advantage is that work has been done for vaccine development on the other coronaviruses in the past. This gives way to a “head-start” for COVID-19 development, of sorts.
The surface of the virus has spikes sticking out of it. In fact, that is how the virus gets its name. The spikes make the virus look like a crown, hence the name “corona.”
The spikes are made out of proteins. The scientific name for the spike proteins is “S-proteins.” When the virus approaches one of the cells inside a person to initiate an infection, the S-proteins bind to the human cells, allowing the virus to enter human cells. A vaccine that can bind to the S-proteins would block their ability to attach to human cells and, resultantly, prevent infection, and then block the virus from reproducing.
Coronavirus vaccine difficulties
Vaccines can be proteins that bind to the surface of a virus or germ and neutralize it. Additionally, they can subsequently recruit other cells (T cells) of the immune system to come in and destroy the virus or cells infected with the virus.
Earlier research on coronaviruses identified some obstacles to developing a COVID-19 vaccine.
- Poor safety profile. In lab animal testing, earlier vaccine trials did not prevent infection, but they did improve overall animal survival. However, they caused lung damage. Safety concerns were an issue, and any successful vaccine must be safe in humans.
- Long-lasting protection. Another challenge was that in a small percentage of vaccinated test subjects, there appeared to be reinfection with the same virus. The reinfection was usually milder, but still, a more durable protective period is required.
- Protecting elderly patients. The high-risk groups for COVID-19 include those over the age of 50. Unfortunately, this age group does not respond well to vaccinations. The best COVID-19 vaccine will need to work in those patients over the age of 50.
Development routes, types of vaccines
Live vaccines use a weakened (often called “attenuated”) version of the virus/agent that causes the disease. Because the virus has been weakened, its ability to cause disease has been reduced. It will not cause infection, but it will create immunity.
Live vaccines are commonly used in vaccines for measles, mumps, rubella, smallpox and chickenpox. Scientists are very familiar with developing these types of vaccines.
However, live virus vaccines need specialized safety testing. Even if a virus is reduced in strength, it can still be problematic in persons who have weakened immune systems.
Inactivated vaccines use a germ that generally would cause disease, but it has been killed or inactivated. This vaccine includes an immune response but does not create an infection. Sometimes only pieces of the virus or constructed pieces of multiple viruses without genetic information are used for this type of vaccine.
Inactivated vaccines have been used to prevent hepatitis A, rabies, and the flu.
Unfortunately, the quality of protection offered by inactivated vaccines may not always be as strong as those produced by live vaccines. Additionally, inactivated vaccines may require multiple doses for long-term immunity.
Genetically engineered vaccines
This type of vaccine uses genetically constructed RNA or DNA that carries the instructions for making copies of the target proteins, like the “S-proteins.” When human cells make these foreign proteins, it can cause the immune system to mount a response to the virus. The advantage of this type of vaccine is that no dangerous virus must be used/handled at all.
Theoretically, these are very intriguing and are currently in development for COVID-19. None have been used successfully in humans yet, but they have recently entered phase 3 trials.
There is another new genetically engineered-like vaccine in development. Scientists are constructing monoclonal antibodies, much like the medicines touted in many TV commercials to treat psoriasis. These antibodies will attach to the spike proteins of COVID and assist the body to rid them faster. This is much like the antibodies found in the plasma of patients who have recovered, but available in larger and limitless supplies. These may not be used to prevent infections, but will be part of a treatment program.
The COVID-19 vaccine timeline
Usually, vaccine development can take years. However, given the devastating global effects of COVID-19, there are several vaccines already in or about to enter phase 3 trials. Typically, drugs that are fast-tracked (e.g., Operation Warp Speed) can get approved approximately six months after phase 3 trials begin. As a result, we may have a viable vaccine in the first quarter or first half of 2021.
You may have heard that Russia has developed a vaccine, but careful evaluation reveals that the announcement was premature because the Russian vaccine is not approved for human use until 2021, when the appropriate safety and efficacy tests have been completed.
Questions still unanswered
- When will the vaccine be available and who will get it first?
- How many vaccinations will be required for adequate protection?
- How long will the protection last?
The good news is that doctors are getting better at treating patients with COVID-19. The bad news is that we are not as responsible as we should be, and the first wave of the virus is still with us and not letting up anytime soon. To break this deadly cycle, wear masks, wash hands, and maintain social distance. Hopefully, a vaccine will be available within the next year or sooner.
Charles E. Crutchfield III, MD is a board-certified dermatologist and clinical professor of dermatology at the University of Minnesota Medical School and a Benedict Distinguished Visiting Professor of biology at Carleton College. He also has a private practice, Crutchfield Dermatology in Eagan, MN. He received his MD and Master’s Degree in molecular biology and genomics from the Mayo Clinic. He has been selected as one of the top 10 dermatologists in the United States by Black Enterprise magazine. Minnesota Medicine recognized Dr. Crutchfield as one of the 100 Most Influential Healthcare Leaders in Minnesota. Dr. Crutchfield specializes in skin-of-color and has been selected by physicians and nurses as one of the leading dermatologists in Minnesota for the past 18 years. He is the team dermatologist for the Minnesota Twins, Vikings, Timberwolves, Wild and Lynx. Dr. Crutchfield is an active member of both the American and National Medical Associations and president of the Minnesota Association of Black Physicians. He can be reached at CrutchfieldDermatology.com or by calling 651-209-3600.