It can take several years for a new vaccine to be developed. Most vaccines take 10 to 20 years of development, testing and clinical trials before they are approved for public use.

More than 100 possible vaccines for COVID-19 are in various stages of development around the world, according to the World Health Organization — some of which have begun clinical trials.

But even when scientists develop a vaccine that works against COVID-19, it could be 12 to 18 months at best before it’s ready for the public. That’s only a fraction of the usual time and due to advanced vaccine development processes being explored to develop vaccines. While this timeframe may be faster than the typical 10 to 20 years, development and safety testing must and will still be conducted before a vaccine is offered to the public.

Vaccines undergo a rigorous review of laboratory and clinical data to ensure the safety and effectiveness. Vaccines approved for marketing may also be required to undergo additional studies to further evaluate the vaccine and often to address specific questions about the vaccine’s safety, effectiveness, or possible side effects.

The significant impact of COVID-19 has led to unprecedented, worldwide collaboration amongst scientists, health and government officials and manufacturers. On May 15, 2020, the Trump Administration announced a national program to accelerate the development, manufacturing, and distribution of COVID-19 vaccines, treatments and medical countermeasures, called Operation Warp Speed. The program will bring together leaders from the U.S. Department of Health and Human Services, the Centers for Disease Control and Prevention, the Food & Drug Administration, the National Institutes of Health, and the Department of Defense, as well as private firms. Experts from these organizations will oversee the process and protocols for COVID-19 vaccine development, manufacturing and distribution, with the goal of having substantial quantities of a safe and effective vaccine available in the U.S. by January 2021.

Sources:
WHO: Q&A on coronaviruses (COVID-19)
WebMD: COVID-19 Vaccine
FDA: COVID-19 Frequently Asked Questions