Did you get the Johnson & Johnson COVID-19 vaccine? Here’s what you should know.

On Tuesday, the Food & Drug Administration and the Centers for Disease Control and Prevention put giving the Johnson & Johnson vaccine on pause while they investigate reports of blood clots in six women ages 18 to 48 who received the vaccine. In the U.S. 6.8 million people have received the Johnson & Johnson vaccine.

We asked Dr. Manish Naik, chief medical Information officer at Austin Regional Clinic, and Dr. Brian Metzger, medical director of infectious diseases at St. David’s Medical Center, what people who have received this vaccine should know about these cases and this vaccine.

It’s good to pause to check data

First, it’s a good thing that the FDA and CDC are being very cautious and pausing to try to figure out if the vaccine is causing these clots, known as cerebral venous sinus thrombosis, they say.

Even if the FDA and CDC find a link between the Johnson & Johnson vaccine and these clots, the chance of these clots happening is less than 1 in 1 million, Metzger says. He compares that to a 1 in 1,000 chance of dying from COVID-19.

Watch for these symptoms

People should not panic if they have received this vaccine, but they should be on the lookout for symptoms.

If you have received the Johnson & Johnson vaccine in the last three weeks, alert your health care provider if you experience unusual headaches, pain in one leg, shortness of breath, or abdominal pain.

“It should not be subtle,” Metzger says. “These clots in general would land somebody in the hospital.”

What to do if you have symptoms

If you experience these symptoms, make sure to alert your medical team that you had the Johnson & Johnson vaccine and the date you received it. That will help with diagnosis and to make sure you receive the right treatment. There are some anticoagulant medications that can be given for this type of blood clot, but some that should be avoided. Some of these clots also might need to be surgically removed.

“If you are a month out from vaccination, you should be fine,” Metzger says.

“The good news is that a lot of people have received the vaccine and done fine and that is in fact true of the Johnson & Johnson vaccine,” Naik says.

The clots that might be tied to this vaccine have been a concern of the AstraZeneca vaccine, which is similar in structure. Doctors have seen two different kinds of clots in women younger than 60 who received the AstraZeneca vaccine, with 86 cases and 18 deaths.

It’s not clear why that is, Naik says, but it could be an immune response to the vaccine as well as the smaller structures in the brain women have compared with men, hormonal differences, or certain immune reactions that tend to happen in women versus men. The women with these clots so far have been shown to have low platelet counts, which might point to an immune reaction.

Both Johnson & Johnson, which has emergency use authorization by the FDA, and AstraZeneca, which does not, are adenoviral vector vaccines, which means they use a harmless virus similar to the COVID-19 virus to bring COVID-19 spike proteins into the body to cause the body to launch an immune response to that spike protein and form antibodies.

What about Moderna and Pfizer?

The Johnson & Johnson vaccine is different than the Moderna and the Pfizer, which use mRNA to train your cells to make just the spike protein of the coronavirus; that’s what the body reacts to. These vaccines have not yet had an unreported side effect like the blood clots. More than 180 million doses of those vaccines have been given in the United States.

“The rare events would have shown up by now,” Metzger says. “I don’t think we’re going to see the same thing with Moderna and Pfizer.”

COVID-19 risks higher than vaccine

Doctors worry that this news will cause more people to hesitate to get vaccinated, but the risk of COVID-19 side effects, hospitalization or death is much higher than the risk of these clots.

The best thing to do is to get the vaccine you are offered when you are offered it, Naik says, though most clinics are not offering the Johnson & Johnson vaccine right now while the FDA and CDC is investigating the clots.

“These are rare vaccine side effects,” he said. “Everyone else who got this vaccine should have a good immune response and good protection against hospitalization and death.”

He and Metzger said that the FDA and CDC might come back in a few days and not find a link, or might find a link and recommend that women of a certain age not receive this vaccine and instead get Pfizer or Moderna.

They are hoping that the science and the data the FDA and CDC release about the Johnson & Johnson vaccine will help reassure the public to continue to get vaccinated.

With all vaccines, report your side effects to the CDC and FDA’s VAERS program — which stands for vaccine adverse event reporting system. The CDC also has the V-Safe program that sends you a text message to track your systems.

This article originally appeared on Austin American-Statesman.