How long does it last? Understanding COVID-19 immunity
There is still a lot we don't yet about immunity from COVID-19. How long does vaccine protection last? Will boosters be needed someday?
It's been a year since COVID-19 shut down much of the country and while communities closed, research was, and still is, in full swing.
"We very much are learning in real time. There's never been a situation like this," said Dr. Daniel Kuritzkes, chief of infectious diseases at Brigham and Women's Hospital in Boston.
He said one of the biggest questions surrounds immunity. According to the Centers for Disease Control and Prevention, getting COVID-19 may offer some natural protection. Evidence suggest re-infection within 90 days is rare.
In January, a promising study found lasting immune response, up to eight months after infection in 95% of people who'd recovered from the virus. Kuritzkes cautioned the virus variants could impact this.
"We know in South Africa people who had natural infection, could get reinfected by one of these new variants strains so they may be protected for life from the original strain, but not from the newer strain," Kuritzkes said.
When it comes to immunity through vaccination, researchers are focusing on the volunteers who participated in early stage vaccine trials, about 10 months ago.
"All we can do for now is follow along with how long their antibodies remain high and then later see if any of those people might get infected," Kuritzkes.
Kuritzkes said he expects to get an update in the next few months. In the meantime, work is also underway to figure it out if people will need a booster shot or a yearly vaccination similar to the flu shot. That depends on two factors.
"One, how long does immunity last? Do we see these antibodies levels begin to decline over time and do they reach some level at which there's no longer protection? The second is how important do the variants become? If there's not good cross protection against the variants, do we need a slightly modified vaccine the next time around?" Kuritzkes said.
The answers to these questions will really only come with time. Kuritzkes said the goal of these vaccines is to protect people from getting sick and all three vaccines available are highly effective at doing that.
