The Johnson & Johnson COVID-19 vaccine has been closely monitored for long-term side effects, and large real-world safety data generally indicate a favorable safety profile, but there are rare and serious risks identified post-marketing[4].
The most commonly reported side effects after vaccination are mild and short-term, including pain at the injection site, headache, fatigue, muscle aches, fever, and nausea. These typically resolve within one to two days[1][9].
Rare but serious long-term side effects include:
- Thrombosis with thrombocytopenia syndrome (TTS): This is a rare combination of blood clots and low platelet counts, most frequently occurring in women aged 30–39 within 21 days of vaccination (about 10 cases per million doses). Patients need urgent medical attention if they experience symptoms like severe headache, leg swelling, chest pain, or unexplained bruising beyond the injection site[1][5][9].
- Guillain-Barré Syndrome (GBS): This rare immune-mediated neurological disorder can cause muscle weakness or paralysis. Risk is highest in males aged 50 and older and occurs mostly within 42 days post-vaccination, with a rate of about 100 reported cases per 12.8 million shots in the US. Most people recover fully, but lingering effects can occur[5][7].
- Severe allergic reactions: There is a remote chance of a severe (anaphylactic) allergic reaction, usually occurring within an hour of vaccination and requiring immediate medical intervention[9].
There is no robust evidence that the Johnson & Johnson vaccine causes myocarditis (heart inflammation), a rare side effect mainly associated with mRNA vaccines like Pfizer and Moderna[5].
Extensive surveillance spanning billions of COVID-19 vaccine doses worldwide, including the Johnson & Johnson vaccine, provides reassuring long-term safety data. Serious long-term health complications linked to the vaccine remain exceedingly rare, and regulatory agencies emphasize the benefits outweigh known or potential risks[4][5][7]. The vaccine is no longer available in the U.S. as of May 2023 due to shifting recommendations favoring mRNA vaccines, primarily related to safety benefit comparisons, not ongoing long-term side effect concerns[7].
References
- [1] What doctors wish patients knew about the Johnson & Johnson COVID-19 vaccine – AMA
- [4] ICMRA statement on the safety of COVID-19 vaccines
- [5] FDA Adds New Warning to Johnson & Johnson’s COVID-19 Vaccine Fact Sheet – CareFirst
- [7] Coronavirus Disease 2019 (COVID-19) Vaccine Safety – CDC
- [9] Johnson & Johnson Updates U.S. COVID-19 Vaccine Fact Sheet