Countries across the world have scaled up their booster vaccination campaigns in response to the Omicron variant. A strong body of evidence illustrates the effectiveness of the third dose against the variant, which has been shown to escape the immunity afforded by two shots. Naturally, rolling out a vaccination programme on this scale has meant a small number of people have experienced side effects.
The Australian Government’s Therapeutic Goods Administration (TGA) has been monitoring the side effects of the booster vaccine as it has made its way through the population.
The TGA closely monitors reports of suspected side effects (also known as adverse events) to the COVID-19 vaccines.
The safety body has concluded that “vaccination against COVID-19 is the most effective way to reduce deaths and severe illness from infection”.
Nonetheless, it has received approximately 600 reports of suspected adverse events identified as a third or booster dose.
The most common “adverse event” reported to the TGA following a booster dose is swollen lymph nodes (also called lymphadenopathy).
The side effect is characterised by swelling which may be noticed near the injection site, for example in an armpit, within a few days of vaccination.
“This is a normal and known side effect of vaccines and occurs when the immune system is stimulated,” notes the TGA.
According to the safety watchdog, swollen lymph nodes were observed in the clinical trials.
For Pfizer, this occurred “more frequently after a third or booster dose” (five percent of people) than after the first or second doses (less than one percent of people) in the clinical trials.
For Moderna), this occurred in up to 10 percent of people, reports the TGA.
According to the safety body, this normally resolves without treatment after a week or so.
“People should seek medical attention if swelling persists for more than a few weeks to rule out other causes,” it advises.
