How Long Do The Moderna And Pfizer Covid-19 Vaccines Last?
While researchers still have much to learn about the long-term effects of the COVID-19 vaccines, a new study offers potentially good news for those who've been vaccinated with the Pfizer and Moderna's versions. The study, published in the journal Nature, suggests that these two vaccines produce persistent immunity, meaning those who've received them could be protected for years — and possibly a lifetime.
Conducted by researchers at the Washington University School of Medicine in St. Louis, the milestone study found that up to 15 weeks after receiving their first dose, vaccinated cells were still training themselves to fight the COVID-19 virus. Dr. Ali Ellebedy, lead author of the study and an immunologist at the university, told The New York Times the results were a "very, very good sign."
"It's a good sign for how durable our immunity is from this vaccine," Ellebedy said.
Pfizer and Moderna's vaccines are both mRNA vaccines while the Johnson & Johnson vaccine utilizes adenovirus technology to deliver the COVID-19 to individuals, according to Nurse.org. The CDC explains that mRNA vaccines trigger an immune response by teaching cells how to create a protein. According to the new study, the mRNA vaccines may not require boosters unless the virus evolves dramatically. Anyone who recovered from COVID-19 and was also vaccinated may never need boosters even if the virus transforms significantly.
There's no guarantee, however
The CDC warns that researchers are still learning how long COVID-19 vaccines offer protection, and there are multiple studies being conducted throughout the world about each vaccine's effectiveness. This week, an Oxford University study was released that found mixing the Pfizer and AstraZeneca vaccines offers strong protection against the virus; meanwhile a Reuters report revealed that a military study found some of those vaccinated experienced higher-than-expected rates of heart inflammation.
However, Akiko Iwasaki, an immunologist at Yale, told The New York Times the new study conducted by Washington University School of Medicine in St. Louis is unique. "This kind of careful time-course analysis in humans is very difficult to do," Iwasaki said.
Dr. Ali Ellebedy, lead author of the study, said results indicate the majority of vaccinated people will be protected over the long term, but older adults and people with weak immune systems will likely need boosters.