SALT LAKE CITY (ABC4) – Many Utahns who got the Johnson and Johnson vaccine are wondering if they need an extra booster shot.

Johnson and Johnson came out with a recent report stating their one-dose vaccine is effective against the COVID-19 delta variant.

As Pfizer recommends a second booster shot, many wonder if those with the J&J shot should get a second dose.

Dr. Jeanmarie Mayer, an epidemiologist for the University of Utah Health tells us, “So we don’t know that. That’s being studied right now.”

Dr. Mayer expects results on the booster study sometime soon, adding scientists are not sure if those who got the J&J shot can intermix it with the Pfizer and Moderna vaccine.

“Currently, we are not allowed to go outside the EUA, but the feeling is that in the future that we most likely will be able to,” she says.

Dr. Eddie Stenehjem an infectious disease doctor with Intermountain Healthcare tells us, “We don’t have really solid data on how well J&J does against Delta.”

Dr. Stenehjem says what they do know is the J&J shot works against COVID, and right now there is one major side effect doctors know comes with the shot.

“The J&J vaccine has the risk of clotting,” he says.

Dr. Stenehjem says the risk of blood clots is extremely low and is easy to detect.

“Adverse events due to vaccines occur during the first two months,” he says. “That’s when the safety signals occur.”

Doctors say the COVID virus is changing, and the Delta variant is much more contagious no matter what shot you receive.

Dr. Mayer says even if you are the breakthrough case, you’re less likely to be hospitalized with a severe infection, but there’s still a concern.

“So they can transmit and make other people ill.”

That’s why doctors recommend vaccinated folks wear masks indoors until there is a high level of vaccinations in our state.