Moderna/Spikevax bivalent vaccine same safety profile as original dose, 6 in 100,000 report serious adverse events

Mr Ong clarified on Sunday that while any person who previously had an infection and two mRNA vaccine shots has minimum protection, such individuals should not consider an infection as a substitute for a vaccine dose. 

“To keep up-to-date with COVID-19 vaccination, if you are 50 years old or older and have achieved minimum protection, you should receive an additional dose within five months to one year of the last vaccine dose,” he said. 

Addressing concerns surrounding the updated bivalent dose that targets the original SARS-CoV-2 strain and the Omicron BA.1 variant, Mr Ong said that clinical studies have proven that the dose has the same safety profile as the original Moderna/Spikevax mRNA vaccine.

The original vaccine has been administered more than three million times in Singapore, he noted.

“Serious adverse events have been reported in about six in 100,000 vaccinations, and all have recovered or are recovering,” Mr Ong said, adding that the Health Sciences Authority has reported a declining rate of such events with subsequent shots.

This means that fewer people have adverse reactions after taking booster doses compared to taking it as part of the primary series.

Those who are considering of skipping their second booster shot and taking the bivalent dose instead should do so, said Mr Ong. 

“We have basically stopped counting boosters,” he added.

The Moderna/Spikevax bivalent vaccine will be available at all joint testing and vaccination centres from Oct 17.

MODERNA/SPIKEVAX VACCINE FOR YOUNG CHILDREN

Separately, Mr Ong assured the public that it is safe to vaccine children aged six months to five years with the Moderna/Spikevax vaccine, which will be available to them as a primary vaccination. 

He added that serious adverse effects are rare, with no cases of anaphylaxis or pericarditis/myocarditis observed in the clinical trial.

“Common side effects (such as injection site pain, fatigue, headache) were observed less commonly than in adults and subside within two to three days,” said the Health Minister.

Singapore will begin offering COVID-19 vaccinations for children between the ages of six months and four years starting on Oct 25, said MOH on Friday.

The recommended Moderna/Spikevax vaccine dosage for this age group is two doses of 25 micrograms each, spaced eight weeks apart.

“The vaccine from Pfizer BioNTech/Comirnaty, which is a three-dose vaccine for children aged six months to four years, has also been approved and we are awaiting delivery. It should be available by the end of the year,” MOH added.

The Pfizer/Comirnaty bivalent vaccine is undergoing evaluation and is expected to be available by the end of this year, said the ministry. 

The Health Ministry also said in the news release that all COVID-19 vaccination-differentiated measures will be lifted from Oct 10, with restrictions no longer in place for dining in, nightlife establishments and events with more than 500 participants.