There is no denying that 2020 has been a terrible year. The coronavirus pandemic has created new challenges for almost everyone, has halted life as we knew it and has killed more than 235,000 Americans. As we near the end of this year (can you believe it?), were met with concerns about 2021 and a pandemic that is showing no signs of slowing down.

2021 for me is really kind of a mystery, said Susan Hassig , an associate professor in epidemiology at Tulane University. Everything is conditional on so many factors.

Many different scenarios can take place next year depending on what sort of vaccine and treatment options become available, in addition to how seriously the public follows rules set in place by public health officials.

It also depends on what experts learn about the virus as time goes on. Things change every day, and so much of the shape of 2021 is dependent on many moving parts.

But while there are no guarantees, there are some predictions. Below, we spoke with experts across the country about their expectations of what the pandemic will look like next year and what we can do as a society to make 2021 a more positive experience.

Life as we know it will continue to be disrupted, even after a vaccine is widely available

Some promising COVID-19 vaccine news was celebrated this week when Pfizer announced preliminary data from its current trial. The evidence suggests the companys vaccine could be 90% effective in preventing COVID-19. (The data still needs to be independently reviewed. The trial is also still going on and needs to go through a more rigorous vetting process before being released to the public.)

Realistically, while a vaccine will solve many problems and help people complete their day-to-day responsibilities more safely, it wont be a total salve right away. Richard Martinello , the medical director for infection prevention at Yale New Haven Health, stressed that it is going to take a significant amount of time to get the entire country vaccinated.

With most of the vaccines that are being looked at right now, most of them will require a series of two shots and typically those shots are going to be one month apart. So, even if hundreds of millions of doses become available, it is going to take months for the population to get vaccinated, Martinello said.

Additionally, about 70% to 80% of the population needs to be immune from COVID-19 to impact the viruss spread within communities. Martinello said that if we have a vaccine that is even 80% effective, which is a very high efficacy rate, we would need 100% of the population to get the vaccine in order to reach 80% immunity.

Thats a tough task. It requires millions and millions of doses of a completed, safe vaccine. It also requires cooperation. With anti-vaccine individuals and vaccine doubters, it is going to be nearly impossible to get the entire population of the United States to get the vaccine at any point, let alone within the next year.