(Note: this message is drafted for the nonmedical audience)
What’s a swollen node? Lymph Nodes are your primary line of defense leveraged by your inbuilt immune mechanism. Everyone has it (rarely are people born with a defect with the immune mechanism).
Suffice to say, whenever you have an infection or hurt in that part of the body, the lymph nodes enlarge to contain and control the infection.
The same happens when vaccines are given. With Moderna, the incidence of ipsilateral node enlargement is 11% to 16% with a first and second jab, and with Pfizer, it is significantly less. Johnson and Johnson, in its emergency approval document, mentioned none.
Both Covishield and Covaxin uncommonly initiate lymph node enlargement. Such uncommon outcomes are generally in the range of 1-3%. However, with any vaccine, as more data accumulates, the figures are likely to change.
Why does it matter?
Two things are crucial with swollen nodes. First, they are sometimes tender and or painful, with resulting discomfort. Most enlargements are self-limiting and subside on their own. However, occasionally few persist. Of course, it goes without saying that you need to consult your doctor.
The second and most crucial aspect is the persistence of nodes in a female patient that may need a mammogram. Sometimes these nodes are revealed not clinically but on an accidental CT or MRI. It becomes a cause of concern that needs further workup, but in most cases, nothing significant comes out after investigations. However, it is best to investigate despite knowing the pre-investigation probability.
- Beware of an enlarging lymph node on the side of the vaccine shot.
- Generally, these are self-limiting and will subside eventually.
- If swelling persists or keeps enlarging, it is pragmatic to get investigated.
Commonly used terms in the illustration below
Shashank Heda, MD
Founder and Chief Executive
Phone: +1 (650) 996 6745
(A global nonprofit organization for disseminating expertise and insight in the medical care of COVID patients)