The coronavirus vaccine is leading to hope that precautions such as wearing masks and social distancing might be forgone.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, predicted in November that the United States wouldn’t return to normal until the very end of 2021 and hinted that it might not be until 2022.
But vaccines could speed up that timeline.
Once enough people are vaccinated, coronavirus cases will decline, according to Mark Slifka, a professor of microbiology and immunology at Oregon Health and Science University. Once they decline enough, wearing masks and social distancing may no longer be necessary.
“People will still have to wear masks until, and this is the good news, all of the vaccinations have reduced incidence of the coronavirus, and all of these other measures have reduced incidence. We can then finally go back to not wearing masks,” said Slifka.
But don’t expect that to happen in the near future.
“It will take time,” Slifka said. “But it won’t be each individual vaccinated person’s choice. It will occur when the community is immune, then the transmissions go down, and then communities can drop the mandates.”
Slifka noted that the process will not occur uniformly in the U.S., as it may take longer in urban and suburban areas than rural ones.
It is possible that a person can become infected with the coronavirus even after being vaccinated. While the vaccine will likely prevent that person from becoming sick, that person could carry just enough of the virus to transmit it to others. Some scientists have argued that the key to ending masks and other precautions will be whether the coronavirus vaccine can prevent not only illness but also the transmission of the virus. That question has not yet been fully researched.
“The clinical trials show these COVID vaccines are very good at protecting against disease if someone becomes infected, but we don’t know yet whether these vaccines will prevent transmission,” said Stephen Morse, an epidemiology professor at the Columbia University Medical Center. “Most vaccines are probably much better at preventing disease, what takes you to visit the doctor, than at preventing infection and transmission.”
Thus far, only AstraZeneca has released any information about how effective its coronavirus vaccine is at stopping transmission, saying that its vaccine “could help to prevent transmission of the virus, evidenced by lower rates of asymptomatic infection in the vaccines, with further information to become available when trial data are next evaluated.”
Pfizer and Moderna are now testing their vaccines to see if they prevent the infection that can lead to transmission but won’t have data until early 2021.
But Nicole Baumgarth, a professor at the Center for Immunology & Infectious Diseases at the University of California, Davis, suggests that preventing infection might not be that important.
“A person who is vaccinated will have an immune response to the coronavirus, and the time that the virus will be replicating is reduced,” said Baumgarth. “It would reduce the number of days that they would be able to transmit the virus.”
“We can also get a sense of what the vaccine might do by extrapolating from natural COVID,” Slifka said.
He noted that mild cases of COVID-19 are less likely to transmit the virus than severe cases, and asymptomatic cases are 20 times less likely to transmit the virus.
“If you get vaccinated, and you get infected, but you are completely asymptomatic, you are most likely going to have reduced transmission,” Slifka said.
The U.S. will likely have to achieve herd immunity before precautions can be relaxed, and that could take many more months. The exact number of people who would need to be vaccinated to achieve herd immunity is unknown, but Fauci recently said it would be 80% to 85%. He had previously said 70% to 75%.
Data scientist Youyang Gu predicts that the U.S. will reach herd immunity, at least 60% of the population being immune, thanks to vaccination or previous infection, by the summer of 2021. That is also his best estimate for when life returns to normal.
“It will probably be until late summer or fall before there is a sufficiently high number of people vaccinated that we could think about not wearing masks and so forth,” said Baumgarth. “Right now, the focus should be on how we make sure the maximum number of people are willing to take the vaccine. That should be our biggest worry. … If we can get the numbers up, we can stop the virus transmission.”
