CDC’s ACIP: Benefits of Janssen Vaccine Outweigh the Risks, Pause Lifted

April 24, 2021

By Denise Baez

The Centers for Disease Control and Prevention’s (CDC’s) Advisory Committee on Immunization Practices (ACIP) recommended that the Janssen/J&J adenovirus vector coronavirus disease 2019 (COVID-19) vaccine (Ad26COV2.S) continue to be used in people aged 18 years and older under the US Food and Drug Administration’s Emergency Use Authorization (EUA).

The vote was not unanimous -- 10 in favour, 4 opposed, and 1 abstained to vote due their involvement with vaccine clinical trials.

The 4 opposing votes were not due to the use of the vaccine itself, but rather the lack of language in the EUA describing the increased risk of thrombosis and thrombocytopenia syndrome (TTS) in women aged younger than 50 years, and the lack of a specific recommendation (ie, choose an mRNA COVID-19 vaccine) for this patient population.

The ACIP held an emergency meeting today, April 23, 2021, to make interim recommendations on the use of the Janssen COVID-19 vaccine after cases of TTS were reported in women aged 18 to 49 years following receipt of the vaccine.

The ACIP concluded that the benefits of the Janssen COVID-19 vaccine outweigh the risks.

As of April 21, 2021, 7.98 million doses of the Janssen COVID-19 vaccine have been administered in the United States, and 15 confirmed TTS cases have been reported -- 13 in females aged 18 to 49 years and 2 in males aged 50 years and older. Additional potential TTS cases are under review, including potential male cases.

With continued use of the Janssen COVID-19 vaccine in individuals aged 18 years and older, modelling showed that we can expect to see 26 to 45 TTS cases, depending on vaccine uptake. However, depending on uptake and amount of transmission, continued use will lead to between 800 and 3,500 fewer intensive care unit (ICU) admissions and 600 to 1,400 fewer deaths. Among individuals aged 50 years and older, we could expect to see 2 to 3 TTS cases depending on uptake, and depending on uptake and amount of transmission, 300 to 1,000 fewer ICU admissions and 40 to 250 fewer deaths.

When modelling was done for females only, results showed that for every 1 million doses of vaccine given with current US exposure risk, there will be 13 cases of TTS among females aged 18 to 49 years. However, 12 deaths will be prevented, 127 ICU admissions will be prevented, and 657 hospitalisations will be prevented. In females aged 50 years and older, for every 1 million doses given, there will be 2 cases of TTS, 593 deaths prevented, 1,292 ICU admissions prevented, and 4,794 hospitalisations prevented.

The pros of continued use is that it allows for flexibility/choice, and allows for use of the vaccine in harder to reach populations. The cons included that the burden to understand the risk falls on individuals; the burden to convey the risk falls on health departments and healthcare professionals; continued use may lead to more cases of TTS; and at-risk populations for COVID-19 are likely at risk for barriers to TTS identification and treatment.

TTS is a rare, but clinically serious and potentially life-threatening AE that has been observed in association with the Janssen COVID-19 vaccine.

“It’s an unusual thrombotic event -- different from what we see in clinical practice,” said Committee member Michael Streiff, MD, Johns Hopkins Medicine, Baltimore, Maryland.

The risk factors for TTS are unknown. Headache appears to be the main presenting feature, and physicians should maintain a high level of suspicion in patients presenting with headache after receipt of the Janssen COVID-19 vaccine. Initial symptoms start 6 or more days after vaccination. Other symptoms include chills and fever. Symptoms seen later in clinical course include headaches (several with neck pain or stiffness), nausea/vomiting, abdominal pain, weakness, speech difficulty, gaze deviation, loss of consciousness, and seizure.

Healthcare professionals should NOT administer heparin to patients presenting with
thrombotic events and thrombocytopenia after receiving the Janssen vaccine.


SOURCE: Centers for Disease Control and Prevention