COVID-19 vaccine rollout in the United States has been disjointed.

Johnson & Johnson asked the U.S. Food and Drug Administration to approve its one-dose regimen in the coming weeks under the Emergency Use Authorization on Thursday. Once granted permission to begin distribution, this vaccine will become the third coronavirus vaccine to hit the market.

So far, 36.7 million doses of the Pfizer and Moderna vaccines have been administered nationwide. But many Americans, who are 65-years or older and or immunocompromised, have struggled to book an appointment. Many have received zero guidance on how to get the process of their vaccination rolling. Many states have claimed that they have received fewer doses than promised, leading to the vulnerable being shut out of their opportunity of avoiding the deadly disease.

In the meantime, Dr. Amira Roess, professor of Global Health and Epidemiology at George Mason University, believes there is only one way to slow the spread of coronavirus as the vaccine rollout process has gone slower than expected.

“One of the biggest problems we are facing in the U.S. is pandemic fatigue. We have never been able to convince more than half of our population to wear masks,” said Roess. “If we were all to wear masks, this pandemic would certainly have been under control sooner, and we would not have had the number of cases and outbreaks that we did.”

Now, the United States is dealing with another dilemma within the coronavirus pandemic. The virus has mutated, and even more contagious strands of COVID-19 from the United Kingdom and South Africa are being reported on American soil.

Former FDA Administrator Scott Gottlieb sounded the alarm on this strand a few weeks ago. He said that the UK strand, specifically, could be the dominant strand in the United States by the end of March.

Roess added that because of the warning behind the UK strand, achieving herd immunity could be more complicated than predicted, but is certainly possible with having effective yet accessible vaccines available to the public.

“First, studies are suggesting that after eight months, some of those infected may no longer be immune. Second, there are several ‘new’ strains circulating, including the UK strain, which is more infectious,” said Roess. “This means that as individuals recover, they [may] be susceptible to new strains that are more infectious. Together this suggests that achieving high levels of vaccination is critical to achieving herd immunity.”

Most scientific journals state that herd immunity could be achieved as early as the third quarter of this year, assuming vaccines are rolled out even faster and make it into the arms of at least 75% of the public.

Some studies believe that Americans with antibodies could help achieve herd immunity sooner. However, with the pandemic’s unpredictable conditions, it is still too early to determine when the end will be. With the lack of testing in the hardest-hit communities around the country, it is unclear how many Americans have developed a short-term immunity from the virus.

“While we have made remarkable progress in scaling up testing and developing vaccines and scaling up their distribution all in record time, this is still a new virus, and there are a lot of unknowns,” said Roess.

A large amount of “anti-vaxxers” fear the medical community. As Roess mentioned, a significant majority of Americans would need to be vaccinated to achieve herd immunity and resume normal activities.

“It will be critical to see more people get vaccinated and remember vaccines don’t work right away, so it is necessary to continue to wear masks and practice social distancing.”