UCHealth: COVID-19 Booster Shots: What You Need to Know!

28 May UCHealth: COVID-19 Booster Shots: What You Need to Know!

We curated this excellent article by Todd Neff from UCHealth Today. The title: “COVID-19 booster shots: What you need to know” Neff goes on to say: “Need for COVID-19 booster shots will depend on how long initial protection lasts and viral variants’ ability to evade vaccine-based immunity going forward.”

Photo by Cyrus McCrimmon for UChealth.

Although less than half the U.S. population has been fully immunized against COVID-19, medical experts and vaccine specialists are studying and preparing for the need for COVID-19 booster shots. Here’s a rundown of some of the big questions and answers – many of them tentative, as it’s still early days – having to do with coronavirus booster shots.

How long do coronavirus vaccines stay effective?

Both the Moderna and the Pfizer vaccines, which have accounted for more than 95% of U.S. vaccinations so far, remain highly effective for at least six months after the second shot. That’s based on the companies’ April announcements based on vaccinations among clinical-trial participants who received their first shots in summer 2020. As of early May 2021, Johnson & Johnson, maker of the third COVID-19 vaccine that has been granted U.S. Food and Drug Administration emergency authorization in the United States, had not disclosed data on longer-term effectiveness.’

Would COVID-19 booster shots be needed because the immune response from initial vaccination weakens over time – or, as in the case of flu vaccines, because the SARS-CoV-2 virus mutates in ways that render the vaccines less effective – or entirely ineffective?

Dr. Thomas Campbell, who leads the Colorado portion of the Moderna COVID-19 vaccine clinical trial, says COVID-19 booster shots are probably in our future, but that, as with so much relating to the coronavirus, much uncertainty remains.

Either/or – or both. The weakening of initial vaccine-based immunity over time, the potential of viral variants to render coronavirus vaccines less effective, or a combination of the two could trigger the need for COVID-19 booster shots, Campbell says.

“I think there’s a good chance that boosters will be needed,” he says, “but we don’t know how often they’ll be needed.”

The need for boosters and their frequency, he says, will depend on the ultimate longevity of the initial doses – still an open question – and whether viral variants emerge that can dodge today’s vaccines…

Continue reading here to learn about effectiveness of vaccines against variants, possibility of diminishing vaccine immunity over time, and more.