An infectious disease expert and hospital chief epidemiologist at the University of Florida Health, Nicole Iovine, said it takes the average person 10 to 14 days to build up a protective number of antibodies, but each person is different.

“It takes a few weeks for the body to build up immunity after receiving a dose. Every day that goes by, the chance you get infected goes down a little bit,” she added.

The Pfizer-BioNTech and Moderna vaccines now in use in the United States require a second dose a few weeks after the first to reach full effectiveness, experts say.

Researchers also note that vaccines do not work retroactively.

A professor of family medicine and public health at the University of Pittsburgh, Dr. Richard Zimmerman, said it takes a few weeks for a person to build up to the intended level of immunity after the second dose.

“You can already be infected and not know it when you get the vaccine — even if you recently tested negative.

“That infection can continue to develop after you get the vaccine but before its protection fully takes hold, and then show up in a positive test result,” experts at the University of Central Florida say.

They warn that taking a COVID-19 vaccine doesn’t mean that a person is 100 percent immune to the coronavirus.

“COVID-19 vaccination works by teaching your immune system how to recognise and fight the virus that causes COVID-19, and this protects you from getting sick with COVID-19.

“Being protected from getting sick is important because even though many people with COVID-19 have only a mild illness, others may get a severe illness, have long-term health effects, or even die.

“There is no way to know how COVID-19 will affect you, even if you don’t have an increased risk of developing severe complications,” Centres for Disease Control and Prevention states.

Indeed, the efficacy rates for Pfizer-BioNTech and Moderna vaccines are extremely high, but they are not 100 percent, experts say, and those vaccinated might still get infected because of the community spread.

“If a vaccine is 95 percent effective, that means there’s still a small chance of infection,” experts warn, hence the need for observance of non-pharmaceutical protocols such as make use, regular handwashing, and maintaining social distance, among others.

Again, the CDC states that if your body develops an immune response — the goal of vaccination — there is a possibility you may test positive on some antibody tests.

The CDC states, “It can take weeks for a person’s body to build up immunity after getting vaccinated.

“That means it’s possible a person could be infected with the virus that causes COVID-19 just before or just after vaccination and get sick. This is because the vaccine has not had enough time to provide protection.”

Continuing, the agency said, “Antibody tests indicate you had a previous infection and that you may have some level of protection against the virus;” adding that experts are currently looking at how COVID-19 vaccination may affect antibody testing results.

Meanwhile, scientists say it is not currently known how effective the vaccines are at preventing the coronavirus from infecting people, or at keeping people from passing it on to others.

That is why vaccinated people should keep wearing masks and maintaining social distance, they enthuse.

Physicians, however, urge those who test positive for the coronavirus to get vaccinated after recovering because the vaccine provides better protection than natural infection.

source: Punch