Covid-19 vaccine and immunity Q-and-A

As the coronavirus pandemic rages on, there’s more controversy than clarity when it comes to issues like lockdowns, vaccines, immunity and origin. 

Dr. John Dye, the lead virologist at the US Army Medical Research Institute of Infectious Diseases answered some of our questions.

Q: What’s the difference between a different “variant” and a different “strain” of coronavirus?

A: No new “strains” have been detected in the U.S. There is a U.K. “variant” that has shown up in this country, which is no surprise. Strains are more different from the original virus than variants. Existing treatments and vaccines are less likely to work against new strains, and more likely to work against new variants.

Q: Has the U.S. ruled out the theory that Covid-19 came from the Wuhan, China lab?

A: No, nothing has been ruled out. We may never know the true origin because we have no original, early sample of the virus, such as from Wuhan, China to conduct a DNA examination and comparison. 

Q: When a vaccine is said to be 90% effective, does that mean for the rest of one’s life?

A: No. Right now, the Covid-19 vaccines have been tested only for weeks or a few months. It’s impossible to know how long immunity will last, but it typically wanes after months or years. We’ll know more as time goes on, but some people may need a booster in six months. Others may need one in a year or two depending upon how their immune system responds.

Q: What happens between the first and second dose?

A: Your immunity is building but not complete.

Q: The first two US vaccines are “RNA” vaccines. What does that mean?

A: It refers to the “modality” of getting the protein into your system. In the past, RNA vaccines are somewhat limited in terms of how quickly it helps you develop immunity and how long it lasts. That’s why you need the booster 21 or 28 days later. But even with the non-RNA vaccines coming out, you’ll likely need a booster because immunity wanes over time.