US study finds adverse reactions to Moderna vaccine are rare

A study from the United States found that severe allergic reactions to Moderna's COVID-19 vaccine is "rare". US health authorities claimed that only 10 cases of severe reactions arose among four million first doses.

The US Centers for Disease Control and Prevention added that widespread vaccination was critical in fighting the pandemic.

"Based on this early monitoring, anaphylaxis after receipt of Moderna Covid-19 vaccine appears to be a rare event," the CDC said in a report.

No deaths were reported in adverse reactions.

As per CDC data, ten cases of anaphylactic shock were recorded among 4,041,396 first doses of the vaccine, which were administered between December 21 and January 10.

The CDC added that six cases required hospitalisation, while four were treated in an emergency setting.

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Based on the numbers, 2.5 cases of anaphylactic shock were recorded for every million of Moderna injections, when compared to 11.1 cases per one million Pfizer vaccinations.

"The clinical and epidemiologic characteristics of anaphylaxis case reports after receipt of Moderna Covid-19 vaccine are similar to those reported after receipt of the Pfizer-BioNTech Covid-19 vaccine," the report said.

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All 10 severe reactions were recorded among women aged between 31 and 63. Out of these, nine had a history of allergic reaction, but even then not to vaccines.

A higher ratio of severe reactions was also recorded in data from Pfizer's vaccine. Experts believe this could be due to more women receiving the vaccinations as compared to men.