'Genetic Recombination Method' Novavax Reports 666 Adverse Event Cases... Fewer Than Janssen and AZ

430,000 Vaccinations Over 4 Months... 154.8 Reports per 100,000 Cases
More 'Felt Sick' Responses After 2nd Dose Than 1st Dose

[Image source=Yonhap News]

[Asia Economy Reporter Jo In-kyung] Reports of adverse reactions to the 'Novavax' COVID-19 vaccine, which began administration in February this year, have been significantly lower compared to existing vaccines.

According to data released on the 18th by the COVID-19 Vaccination Response Promotion Team titled 'Surveillance Status of Adverse Reactions After Novavax Vaccination,' a total of 666 cases of adverse reactions following Novavax vaccination were reported to the COVID-19 Vaccination Management System from February 14, when Novavax vaccination started in South Korea, through May 7.

During this period, the number of Novavax vaccinations was 430,339 doses, with an adverse reaction reporting rate of 154.8 cases per 100,000 doses. This rate is approximately 26% to 50% of the rates reported for other COVID-19 vaccines: Janssen (586.7 cases per 100,000), AstraZeneca (539.1 cases), Moderna (464.7 cases), and Pfizer (309.7 cases).

The Novavax vaccine was developed using a recombinant (synthetic antigen) method, which has been used for a long time in existing vaccines such as hepatitis B and influenza vaccines. Compared to messenger RNA (mRNA) vaccines like Pfizer and Moderna, and viral vector vaccines like AstraZeneca and Janssen, Novavax is known to have fewer concerns and resistance regarding side effects.

Among the reported adverse reactions to the Novavax vaccine, the majority (637 cases, 95.6%) were 'general adverse reactions' such as muscle pain, headache, chest pain, and allergic reactions. However, there were also cases of death (7 cases), suspected anaphylaxis (10 cases), and serious adverse reactions (12 cases). Serious adverse reactions include special interest adverse events, life-threatening conditions, permanent disability, and intensive care unit admissions.

Meanwhile, the response team monitored the health status of 2,885 individuals who received both their first and second doses of the Novavax vaccine. Among those aged 18 to 64, 47.1% reported experiencing at least one health issue or adverse reaction within 0 to 7 days after the first dose. After the second dose, 72.4% reported health problems, which was higher than after the first dose.

Among those aged 65 and older, health problem occurrences were also higher after the second dose (47.1%) compared to the first dose (32.4%).

The response team added, however, that "since the observation period after Novavax vaccination is relatively short compared to other COVID-19 vaccines, caution is needed when interpreting these results."

This content was produced with the assistance of AI translation services.