AusVaxSafety study affirms short-term safety profile of Moderna and Novavax COVID-19 vaccine priming doses

A recently published post-licensure safety analysis of COVID-19 priming doses (i.e. a first or second dose of any COVID-19 vaccine) has affirmed the short-term safety and reactogenicity of the original monovalent Nuvaxovoid (Novavax) and Spikevax (Moderna) COVID-19 vaccines in real-world conditions.

The research, led by AusVaxSafety, analysed data from more than 50,000 Moderna and Novavax COVID-19 vaccine priming dose recipients who participated in active vaccine safety surveillance via the AusVaxSafety system between September 2021 and September 2023.

Around half of the respondents (50.7%) reported at least one adverse event following immunisation (AEFI) in the first three days after vaccination. AEFI rates were higher following dose 2 compared with dose 1 for both the Moderna (64.2% vs 41.7%) and the Novavax (57.3% vs 36.6%) COVID-19 vaccines.

Study author Dr Lucy Deng (AusVaxSafety Clinical Lead) said, ‘Reported rates of adverse events for both Moderna and Novavax COVID-19 vaccine priming doses were lower in our study than those observed and reported in clinical trials.

‘AEFI rates were highest in individuals aged 30–39 years for both vaccine brands. Females were more likely to report adverse events than males across most age groups, vaccine types and doses,’ continued Dr Deng.

Fatigue, pain at the injection site, headaches, myalgia (muscle aches and pain) and arthralgia (joint stiffness) were the most frequently reported AEFIs.

Overall, 3% of respondents required medical review (including phone consultation) in the three days following vaccination – a higher proportion than for recipients of priming doses of other COVID-19 vaccines used in Australia (Vaxzevria [AstraZeneca]: 0.9%; and Comirnaty [Pfizer]: 0.9%).

The need for medical review was higher following dose 2 compared with dose 1 for both Moderna (4.8% vs 1.9%) and Novavax (3.9% vs 2.7%) COVID-19 vaccines.

Similarly, an impact of symptoms on daily activities was most frequently reported after dose 2 of both Moderna (35%) and Novavax (25%) vaccines.

Although most of the population have already received COVID-19 vaccine priming doses, this study generates important baseline vaccine safety data that can be used for comparison against ongoing and future additional COVID-19 vaccine doses.

These findings, along with AusVaxSafety’s previous study investigating priming doses of AstraZeneca and Pfizer COVID-19 vaccines in Australia, affirm the short-term reactogenicity and safety profile of all four COVID-19 vaccines administered as primary courses in the Australian population.

Access the full study

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