When are you ‘fully�� vaccinated against COVID-19? Doctors explain why it takes weeks

The answer depends on which COVID-19 vaccine you receive.

The answer depends on which COVID-19 vaccine you receive.

YET. LIKE HOW LONG DOES VACCINE PROTECTION LAST? AND WILL YOU NEED A BOOSTER SOME DAY? TONIGHT, EMILY IS BACK TO TAKE A CLOSER LOOK. EMILY: IT’S BEEN A YEAR SINCE COVID-19 SHUT DOWN MUCH OF MASSACHUSETTS. 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. EMILY: DR. DANIEL KURITZKES IS CHIEF OF INFECTIOUS DISEASES AT BRIGHAM AND WOMEN’S HOSPITAL. HE SAYS ONE OF THE BIGGEST QUESTIONS SURROUNDS IMMUNITY. ACCORDING TO THE CDC, GETTING COVID-19 MAY OFFER SOME NATURAL PROTECTION. EVIDENCE SUGGEST RE-INFECTION WITHIN 90 DAYS IS RARE. AND 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. BUT KURITZKES CAUTIONS 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 -- VARIANT STRAINS SO THEY MAY BE PROTECTED FOR LIFE FROM THE ORIGINAL STRAIN BUT NOT FROM THE NEWER STRAIN. EMILY: 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 PEOP MIGHT GET INFECTED. EMILY: KURITZKES SAYS HE EXPECTS WE’LL 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. AND 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 VARAINTS BECOME? AND IF THERE’S NOT GOOD CROSS PROTECTION AGAINS THE VARIANTS, DO WE NEED A SLIGHTLY MODIFIED VACCINE THE NEXT TIME AROUND EMILY: THE ANSWERS TO THESE QUESTIONS WILL REALLY ONLY COME WITH TIME. IN THE END, DR. KURITZKES

When are you ‘fully�� vaccinated against COVID-19? Doctors explain why it takes weeks

The answer depends on which COVID-19 vaccine you receive.

The U.S. Centers for Disease Control and Prevention recently released new guidance for fully vaccinated people, noting that they can gather indoors in small groups without masks or physical distancing with other fully vaccinated people and with unvaccinated people who are at a low risk of severe COVID-19.While the new guidelines are exciting, it’s important to remember that COVID-19 is still spreading, so some precautions still need to be taken, according to Richard Watkins, M.D., an infectious disease physician and professor of internal medicine at the Northeast Ohio Medical University. One of those precautions is making sure you’re fully vaccinated before visiting with family or friends indoors without a face mask. Not sure what it means to be “fully�� vaccinated? Read on to learn everything you need to know.When are you considered “fully�� vaccinated against COVID-19?It depends on which vaccine you get. The CDC currently says that you’re considered fully vaccinated when you meet the following criteria: It’s been at least two weeks since you had the second shot in a two-shot series (i.e. with the Pfizer-BioNTech or Moderna vaccines). It’s been at least two weeks since you received the Johnson & Johnson vaccine, also known as the Janssen vaccine.But, if you want to be really safe after getting the Johnson & Johnson vaccine, you’ll wait four weeks to consider yourself fully vaccinated, says Thomas Russo, M.D., professor and chief of infectious disease at the University at Buffalo in New York. The reason: During clinical trials of the Johnson & Johnson vaccine, an immune response was detected in 76-83% of people aged 18 to 55 and in 60-67% of people over 65 after 15 days; by day 29, though, 90% of participants had antibodies in their blood, regardless of age. In other words, you reach peak immunity 29 days after the vaccine, which is why Russo said: “I tell patients that they should wait at least four weeks at this point.�� How long does it take for antibodies to develop after the COVID-19 vaccine?Once you receive the vaccine, your body starts developing antibodies to SARS-CoV-2 (the novel coronavirus) pretty quickly, Watkins said. But those antibodies build over time. “It’s a linear process,�� he said. “It starts shortly after the vaccine enters the body, and then takes off.”The Johnson & Johnson vaccine, for example, found that 90% of clinical trial participants had neutralizing antibodies against SARS-CoV-2 on day 29 after being vaccinated while 100% of study participants had neutralizing antibodies by day 57. In the two-dose vaccines �� Pfizer-BioNTech and Moderna �� you essentially get a booster vaccine after the first dose, which “significantly increases the amount of antibodies,�� Russo said. “The second shot is absolutely critical.”Why is full vaccination important before you start doing “normal�� things again?Currently, the CDC says you can do the following when you’re fully vaccinated: Visit with other fully vaccinated people indoors without wearing masks or physical distancing. Visit with unvaccinated people from a single household who are at low risk for severe COVID-19 disease indoors without wearing masks or physical distancing. Avoid quarantine and testing following a known exposure if you don’t have COVID-19 symptoms. But the “fully vaccinated�� part is crucial here. “You want the optimal immune response that will afford the maximum amount of protection,�� Dr. Russo says. It can be hard to have patience, but experts say that waiting at least two weeks after your last COVID-19 vaccine shot to see loved ones without a mask again will make a big difference in keeping you �� and them �� protected.

The U.S. Centers for Disease Control and Prevention recently released for fully vaccinated people, noting that they can gather indoors in small groups without masks or physical distancing with other fully vaccinated people and with unvaccinated people who are at a low risk of severe COVID-19.

While the new guidelines are exciting, it’s important to remember that COVID-19 is still spreading, so some precautions still need to be taken, according to , an infectious disease physician and professor of internal medicine at the Northeast Ohio Medical University.

One of those precautions is making sure you’re fully vaccinated before visiting with family or friends indoors without a face mask. Not sure what it means to be “fully�� vaccinated? Read on to learn everything you need to know.

When are you considered “fully�� vaccinated against COVID-19?

It depends on which vaccine you get. The CDC currently says that you’re when you meet the following criteria:

It’s been at least two weeks since you had the second shot in a two-shot series (i.e. with the Pfizer-BioNTech or Moderna vaccines).
It’s been at least two weeks since you received the Johnson & Johnson vaccine, also known as the Janssen vaccine.

But, if you want to be really safe after getting the Johnson & Johnson vaccine, you’ll wait four weeks to consider yourself fully vaccinated, says , professor and chief of infectious disease at the University at Buffalo in New York.

The reason: During of the Johnson & Johnson vaccine, an immune response was detected in 76-83% of people aged 18 to 55 and in 60-67% of people over 65 after 15 days; by day 29, though, 90% of participants had antibodies in their blood, regardless of age.

In other words, you reach peak immunity 29 days after the vaccine, which is why Russo said: “I tell patients [who received the Johnson & Johnson vaccine] that they should wait at least four weeks [to see people without a mask] at this point.��

How long does it take for antibodies to develop after the COVID-19 vaccine?

Once you receive the vaccine, your body starts developing antibodies to SARS-CoV-2 (the novel coronavirus) pretty quickly, Watkins said. But those antibodies build over time. “It’s a linear process,�� he said. “It starts shortly after the vaccine enters the body, and then takes off.��

The Johnson & Johnson vaccine, for example, found that 90% of clinical trial participants had neutralizing antibodies against SARS-CoV-2 on day 29 after being vaccinated while 100% of study participants had neutralizing antibodies by day 57.

In the two-dose vaccines �� Pfizer-BioNTech and Moderna �� you essentially get a booster vaccine after the first dose, which “significantly increases the amount of antibodies,�� Russo said. “The second shot is absolutely critical.��

Why is full vaccination important before you start doing “normal�� things again?

Currently, the says you can do the following when you’re fully vaccinated:

Visit with other fully vaccinated people indoors without wearing masks or physical distancing.
Visit with unvaccinated people from a single household who are at low risk for severe COVID-19 disease indoors without wearing masks or physical distancing.
Avoid quarantine and testing following a known exposure if you don’t have COVID-19 symptoms.

But the “fully vaccinated�� part is crucial here. “You want the optimal immune response that will afford the maximum amount of protection,�� Dr. Russo says.

It can be hard to have patience, but experts say that waiting at least two weeks after your last COVID-19 vaccine shot to see loved ones without a mask again will make a big difference in keeping you �� and them �� protected.

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