As COVID-19 vaccinations become more widespread and cases continue to drop nationwide, the end to the pandemic may be in sight.

Although scientists are continuing to advise caution, some feel that this year will not be as detrimentally hit by the coronavirus as the last in the face of immunity. Many aspects of COVID-19 remain to be discovered, but UC Berkeley clinical professor emeritus John Swartzberg remains hopeful of the end.

“I think we can start to see the end of this pandemic,” Swartzberg said. “There was a long time for us that we haven’t been able to see the end of this pandemic so this is very optimistic. The question is not if we’re going to see an end to it, the question is when.”

One of the biggest reasons for the decrease in active COVID-19 cases is the fact that more people are being exposed to it, according to Swartzberg.

People who have been exposed and survive will develop an immunity to the virus for several months or longer, leading to a greater possibility of herd immunity, according to Swartzberg.

A term that has gained notoriety in recent days, Swartzberg said herd immunity refers to the point in time when enough people have already been exposed that the virus in question can no longer find new hosts, ultimately ceasing to spread as quickly.

“We don’t know what herd immunity is for this virus,” Swartzberg said. “We can only guess, and the reason we don’t know is because the virus itself is changing in terms of its ability to transmit. As it becomes more transmissible, the herd immunity numbers go up so it is constantly changing.”

Some reports in the United States found about 28 million Americans have been infected by COVID-19, but in actuality, that number is likely at least four times higher, leaning closer to 120 million to 150 million infected, according to Swartzberg.

If the immunity people obtain from natural infection in fact persists for a long time, then there is evidence that it probably does so for at least six to eight months, according to Swartzberg. Americans may be at about 30% to 50% on the way to herd immunity, which represents an optimistic figure, according to Swartzberg.

While this may be the trajectory, many professionals still believe there is work to be done as we move toward a general herd immunity.

“I think we’re at a critical stage in the coming four to six weeks and that is we’re going to know if these mutational variants of COVID have been successful at taking over,” Swartzberg said. “It is going to be up to us as a community to be mindful in continuing to practice diligent mask-wearing and sanitizing. The state of this pandemic is still very much fluid, and if we start to get reckless, we can enter into a possible fourth surge.”