Note: For the latest on coronavirus vaccines, visit this tracker created by the New York Times.
Since the COVID-19 pandemic began, one of the biggest questions is how quickly researchers can develop a vaccine for the deadly disease.
Part of what makes COVID-19 so contagious and dangerous is that it is a new illness against which humans have no natural immunity. Therefore, a COVID-19 vaccine is essential to preventing the spread of the illness, and limiting its severity when people become infected.
Vaccine development typically takes 9-15 years. To date, the fastest vaccine development was the mumps vaccine, which took four years. Because of the urgency and severity of this pandemic, researchers are working to develop a vaccine as quickly as possible. There are more than 155 vaccines in various stages of development, only nine months after the first known case of COVID-19.
Despite this speed, there is no definitive timeline for when a COVID-19 vaccine will be available. Many experts believe that an effective vaccine is possible by mid-2021, but acknowledge that is an optimistic estimate. There are many challenges in vaccine development that make the 12-18 month timeframe unlikely.
When a person is vaccinated, their immune system develops antibodies against a disease, so that when they come in contact with it, their body knows how to properly fight it.
Although the human immune system can defend against most common germs, for unfamiliar diseases like COVID-19, vaccines are essential to providing protection that our bodies cannot produce on their own.
There are four stages of vaccine development:
The preliminary stage in which researchers learn about the disease, and start identifying ways to prevent it. It typically lasts 2-4 years, but is moving much more rapidly with COVID-19.
Scientists give a vaccine candidate to animals like mice or monkeys to see if it produces an immune response. While this stage usually takes 1-2 years, there are currently over 135 COVID-19 vaccine candidates in preclinical testing. A significant number of vaccine candidates do not make it past this point.
This three-phase stage is the most critical part of the process, when scientists test the vaccine in humans.
If a vaccine candidate makes it through all these stages, regulators in individual countries review the trial results, and determine whether to approve the vaccine for use in their country. This is also a time-consuming process, but in the case of a pandemic, a vaccine may receive emergency use authorization before formal approval. There is currently one COVID-19 vaccine approved for limited use in China.
Here are some of the different types of vaccines being tested for COVID-19:
Scientists racing to create a vaccine against COVID-19 face several challenges, some of which are common in the vaccine development process, and some of which are unique to this situation.
The newness of the disease presents an obstacle, as scientists must first understand a disease, before they can find an effective way to inoculate against it.
Another issue is safety. Scientists must ensure that vaccines work properly, and that they won’t cause any side effects that are equally or more damaging than the disease it is trying to prevent.
This is one of the reasons why there are many regulations in place when it comes to vaccine development, and why the process usually takes years. Scientists must be able to see the long-term effects of a vaccine, to confirm that it is safe for widespread use. Currently, scientists are balancing the urgent need for a COVID-19 vaccine with the necessary precautions to make sure it is safe and effective.
Lastly, once an effective COVID-19 vaccine is approved, there is the final step of manufacturing and distributing the vaccine. Pharmaceutical companies around the world are already gearing up to manufacture millions of doses as soon vaccines are approved, although some types of vaccines, like whole-virus vaccines, will be easier than others to produce on a mass scale because the infrastructure already exists.
|Centers for Disease Control and Prevention (CDC)||https://www.cdc.gov/coronavirus/2019-ncov/index.html||The CDC is the United States’ leading national public health organization. Its mission is to protect public health and safety through the control and prevention of disease, injury, and disability in the U.S. and abroad.|
|World Health Organization (WHO)||https://www.who.int/||A specialized agency of the United Nations, WHO is responsible for international public health. Headquartered in Geneva, Switzerland, it has field offices worldwide.|
|Association of Public Health Laboratories (APHL)||www.aphl.org||The APHL is a nonprofit organization in the United States that represents laboratories that protect public health and safety.|