He also wears two masks in public situations.
Experts we talked to offered several explanations, including protecting those who have not been vaccinated, providing an example to others, and potentially being concerned about the risk the virus still poses despite full inoculation. One also referenced the Centers for Disease Control and Prevention's (CDC) recently released guidelines on what is considered safe for individuals who are fully vaccinated, noting that the shot does not equate to receiving a "free pass" to resume normal life.
"As the vaccinated person, it’s not just about you," Dr. Henry F. Raymond, associate professor, Rutgers School of Public Health, told Fox News. "It’s also about the people you may encounter. The vaccine is not making you immune to becoming infected, the vaccine is mitigating the effect of that infection and hopefully in most cases reducing your risk of developing COVID-19, which is the disease."
Raymond added that there isn’t enough data on the vaccines’ impact on transmission yet, so even if you do not become ill with COVID-19, you could still contract the SARS-CoV-2 virus and pass it on to someone else who is vulnerable.
But optics may also come into play when a leading official — who is fully vaccinated — opts for two masks instead of one.
"It may be interpreted by some that when a high profile vaccinated individual wears a double mask the individual either does not have full confidence in the protection offered by vaccines, has a low threshold for risk of infection, or has, for personal reasons, decided not to unwind some of the infection control mechanisms they have instituted during the past year," Dr. Jesse Pelletier, president of Halodine and head of infection control at two medical centers in Miami, told Fox News.
Biden, at 78, is considered to be at a greater risk of COVID-19 related complications, according to the CDC. Data reflects that 8 in 10 COVID-19 deaths in the U.S. have involved adults 65 years old and older.
And a year into the pandemic that has been hampered by mixed messaging, the timing of a study proving the effectiveness of two masks (or a tight-fitting mask versus one) coinciding with a larger-scale vaccine rollout may have helped cast doubt on what the overall objective of masking is.
"The study was published last month and the data happened to come out at the exact same time that vaccines were rolling out to Phase 1B and people 65 and older," Dr. Sachin Nagrani, medical director of Heal, told Fox News. "The simultaneous messaging [of] 'come get the vaccine' and 'wear two masks' is not good marketing. Sending a clear signal is really important."
Nagrani said the mask study simply proved what should’ve been known all along: The messaging should’ve focused on the importance of ensuring the mask was effective through material choice, proper seals and covering the mouth and nose, versus how many should be used, he said.
"Remember, the reason we are talking about masks still is because we still have the pandemic going on and we haven’t achieved the number of vaccinations to stop wearing masks in public," Nagrani said, adding that now is not the time to drop public health measures. "Continue to maintain those precautions even if you’ve been vaccinated."
As of Monday, the CDC reported over 93.6 million doses of COVID-19 vaccine had been administered, but just 32.1 million Americans are fully inoculated, or about 10% of the country’s population. Iowa, Texas and Mississippi have lifted the mask mandate, citing rising vaccination rates and a decline in new cases and hospitalizations.
However, federal health officials have pleaded with the public to adhere to health and safety measures deployed over the past year, including wearing a mask, regardless of states’ mandates. Two masks for vaccinated individuals, however, may be unnecessary, Pelletier said.
"We are very fortunate to have a spectrum of vaccines which have demonstrated high efficacy in clinical trials, especially against severe illness, hospitalization and death," Pelletier said. "Now vaccines are demonstrating real-world effectiveness in preventing illness and reducing transmission. Because of this, the extra protection that is at times provided by two masks is unnecessary."