Covid-19 vaccine boosters might be necessary. Here’s what you need to know

In the case of Covid-19 vaccines, it remains unknown for how long immune protection lasts, but vaccine developers and health officials know it may not be forever – and that emerging variants could escape immunity.

 

Therefore, a vaccinated person might need a booster dose of vaccine – somewhat similar to how a tetanus booster is recommended every 10 years, or different flu vaccines are recommended every year.

 

Despite such predictions, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told CNN the bottom line is "we don't know."

"We're preparing for the eventuality that we might need boosters, but I think we've got to be careful not to let the people know that inevitably, X number of months from now, everyone's going to need a booster. That's just not the case," Fauci said at a Washington Post Live event. "We may not need it for quite a while."

 

So far, studies have shown that mRNA vaccines – those made by Pfizer/BioNTech and Moderna – maintain more than 90% efficacy six months after getting vaccinated, and scientists say it's likely much longer.

 

Experts say it is also unclear how these antibody levels correlate with real-world immunity, and to what extent other parts of the immune system – such as T cells – could factor into protection.