With Moderna's COVID-19 vaccine now granted FDA emergency use authorization, many Americans are beginning to see the light at the end of the tunnel, nine months after COVID-19 was declared a pandemic by the World Health Organization.
Moderna now joins Pfizer/BioNTech's vaccine, which was granted emergency use authorization last week. But experts say that even with two highly effective vaccines, there's still a lot to learn. Meanwhile, the pandemic is likely to get worse before it gets better.
"Life will not get back to normal immediately," said Dr. Simone Wildes, infectious disease doctor at South Shore Health. But, in the coming months, "the vaccine will be a main part of getting us back to normalcy," she said.
The Pfizer/BioNTech and Moderna vaccines are very similar. Both are messenger RNA vaccines, meaning they provide our bodies with the instructions to recognize the coronavirus and neutralize it before it can spread. Both vaccines have been demonstrated to be safe and effective in large clinical trials, with Moderna's more than 94% effective at preventing COVID-19, and Pfizer's an estimated 95%.
But there are still several unknowns. For instance, it's unknown if the vaccines can prevent asymptomatic disease, or how effectively they stop transmission. And it's also unknown how long protection lasts -- whether it's a few months or a few years.
Which means for now, until scientists can answer those questions, even people who are vaccinated will need to continue wearing masks and keeping socially distant.
Meanwhile, there are logistics challenges that will need to be overcome. For example, both are given in two doses. and both vaccines need to be kept cold -- with Pfizer's at ultra-cold temperatures -- which may limit speedy distribution to smaller towns and rural areas.
This means Americans will likely need to wait several months until enough of society has been vaccinated for life to return to normal. "Most people will not have the vaccine until the spring or early summer," Wildes estimates. At that pace, she predicts, "in the early fall we'll maybe have some type of normalcy."
Dr. Anthony Fauci, the nation's leading infectious disease doctor, has repeatedly said vaccine participation will need to be at least 75% in order to achieve herd immunity and stop the virus. Encouragingly for researchers, Americans' willingness to get a COVID-19 vaccine is increasing.
Dr. Wildes emphasizes that there has been immense misinformation and unwarranted mistrust of the COVID-19 vaccines. She said there is "still a lot of work to be done, especially in communities of color," and that education will be critical in allowing people to have more trust in these vaccines.
Neither the Pfizer/BioNTech or Moderna vaccines are live vaccines, so there is no risk for the vaccines to cause COVID-19. They're not going to change your DNA. But what can be expected, Wildes reminds, are the common side effects -- like pain at the injection site, fever and body aches.
"We need to give people information so they can be aware of what to anticipate," Wildes said. Educating everyone on what to expect will help to avoid false alarms and help prevent people not completing the two-dose vaccination schedule.
Nevertheless, widespread vaccination is still months away. Until then, it will be important that everyone continues to take precautions. Continue wearing a mask, maintaining at least six feet of distance between yourself and others, washing hands, and avoiding large indoor gatherings. The more we all do our part, the sooner we'll be able to return to the way of life that we all once knew.
Nicholas Nissen, M.D., is a clinical fellow and resident physician at Harvard Medical School and a member of the ABC News Medical Unit.