US Warns Of Rare Heart Inflammation From Pfizer & Moderna Covid-19 Vaccine

Heart Inflammation Side Effect Warning Added To Pfizer & Moderna Vaccines

Amid efforts globally to vaccinate their populations, mRNA Covid-19 vaccines like Pfizer-BioNTech and Moderna have been the most commonly used thanks to their high efficacy and safety.

However, reports of rare heart inflammation cases, especially among males, have been reported after the mandatory 2nd dose.

The Food and Drug Administration (FDA) of the United States of America has added a warning to the vaccines as a result.

In Singapore, the vaccination expert committee has also noted 6 cases of the same. 4 of them involve men aged between 18-30.

As of 21 Jun, Singapore has given out more than 5 million vaccine doses, with 2 million having received both doses.

FDA adds warning of rare heart inflammation

On 25 Jun, the FDA added the warning on both Pfizer-BioNTech and Moderna Covid-19 vaccines.


The warning says there’s an increased risk of myocarditis and pericarditis, particularly after the 2nd dose.

Symptoms may occur within a few days after vaccination, it said.

The cases are higher in males, with the United States Centers for Disease Control and Prevention (CDC) identifying 309 hospitalisations under the age of 30.

295 of them were discharged.

Over 1,200 cases have been reported to the US Vaccine Adverse Event Reporting System (VAERS), out of around 300 million doses given.

Singapore notes “very small risk”

The Health Sciences Authority (HSA) said on 11 Jun that it is aware of cases in Israel and the US where heart inflammation occurred after vaccination.

As of that date, 6 cases have been found in Singapore, including 4 men aged 18-30.

Young Men At Risk Of Heart Inflammation After 2nd Covid-19 Jab, Should Avoid Strenuous Activities

It’s warned that young men should avoid strenuous activities for a week following their 2nd jab.

However, given there’ve been over 2 million dosages, the 6 cases appear extremely low.

Rare cases are rare

Despite the warning, MOH has assured that the vaccines are safe, even for the group which shows higher risk of heart inflammation.

According to Reuters, Pfizer and Moderna have not responded to FDA’s issued warning.

Regardless, multiple countries have reported the side effect, albeit rare.

Therefore, the advice on not engaging in strenuous activity after your 2nd dose should apply especially if you’re in the 18-30 range and are a man.

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