En español | After a nearly two-week pause, Americans 18 and older can once again get the one-shot Johnson & Johnson (J&J) COVID-19 vaccine, health officials announced on April 23.
The decision came after an advisory committee to the Centers for Disease Control and Prevention (CDC) determined the vaccine's benefits outweigh any known risks following reports of a rare but serious type of blood clot experienced by a small number of people who had received the J&J vaccine.
During the pause — which was issued out of “an abundance of caution” on April 13 — scientists at the Food and Drug Administration (FDA) and CDC conducted a “thorough review” of all the available data and determined the possibility of the clotting disorder is “very low.” The investigation into the level of potential vaccination-related risk, however, “will continue to be ongoing,” Janet Woodcock, acting commissioner of the FDA, said in a press briefing on April 23.
The health agencies have confirmed 15 reported cases of the blood clotting disorder, all in women ages 18 to 59 who had received the J&J vaccine. Three of the cases were fatal; seven women remain hospitalized. To date, more than 8 million doses of the J&J vaccine have been administered in the U.S.
"What we are seeing is the overall rate of events was 1.9 cases per million people. In women 18 to 49 years, there was an approximate 7 cases per million, and the risk is even lower in women over the age of 50 at 0.9 cases per million,” CDC Director Rochelle Walensky said on April 23.
She went on to explain that more than 650 hospitalizations and 12 deaths in women aged 18 to 49 could be prevented for every 1 million doses of the J&J vaccine administered; more than 4,700 hospitalizations and nearly 600 deaths in women over 50 could be avoided with 1 million shots. “These are significant numbers and show the important impact of this vaccine in our country. In the end, this vaccine was shown to be safe and effective for the vast majority of people,” Walensky added.
Signs of rare blood clots post-vaccination
The fact sheet for the J&J vaccine has been updated to include risks for the clotting disorder, called thrombosis-thrombocytopenia syndrome (TTS), for both health care providers and vaccine recipients. It advises individuals to seek medical attention right away if they experience any of these symptoms after receiving the J&J vaccine: chest pain; leg swelling; persistent abdominal pain; severe or persistent headaches or blurred vision; or easy bruising or tiny blood spots under the skin beyond the site of the injection. Among the known cases, these symptoms occurred six to 15 days after vaccination, setting them apart from the expected vaccine side effects.
The new fact sheet also warns health care providers that heparin — a drug commonly used to break up clots — may be harmful in patients with suspected TTS and that “alternative treatments may be needed.”
The two other vaccines authorized under emergency use in the U.S. — one from Pfizer-BioNTech and another from Moderna — make up the majority of vaccines that have been administered. Both require two doses and use a different technology than the J&J shot, called messenger RNA (mRNA). To date, no clotting disorders have been linked to the mRNA vaccines.
The FDA's Woodcock said individuals who have questions about which vaccine is right for them should discuss their options with a health care provider.
Rachel Nania writes about health care and health policy for AARP. Previously she was a reporter and editor for WTOP Radio in Washington, D.C. A recipient of a Gracie Award and a regional Edward R. Murrow Award, she also participated in a dementia fellowship with the National Press Foundation.