Study About Second COVID-19 Vaccine and Allergic Reactions

This study was done by researchers who had searched MEDLINE, Embase, and the World Health Organization Global Coronavirus database for the risk of a second allergic reaction to COVID-19 vaccines among persons who had a prior allergic reaction to the first dose.

The results show that 22 studies were included for 1,366 individuals (87.8% women; mean age, 46.1 years) with a known or suspected prior allergic reaction to a COVID-19 vaccine, including 78 persons with prior severe immediate allergic reactions (e.g., anaphylaxis) to a COVID-19 vaccine.

This systematic review and meta-analysis found moderate-definitive evidence of a lower incidence of severe immediate allergic reactions associated with the second dose of the COVID-19 vaccine among individuals with a history of severe severity of allergic reactions to their first vaccine dose. Re-vaccination of such individuals was without recurrence in most individuals and did not cause immediate symptoms in approximately 13.65% of individuals.

These findings contradict the general assumption that a history of immediate reaction, including severe immediate allergic reactions to the previous COVID-19 vaccine, guarantees another reaction after re-vaccination. Immunoglobulin E (IgE) may be responsible for similar regenerative allergic reactions — similar to food allergic reactions — but may also occur uniquely and unexplained due to non-IgE-dependent mechanisms of allergic reactions. It may be helpful, if possible, to consult with an allergist before a second vaccination. Removal of immunization barriers is critical to boosting immunity and thereby protecting individuals and communities against COVID-19.

This study has some limitations too. Firstly, the data is too short and it requires further study. Secondly, there is a risk of accuracy in dealing with the type of allergies that the patient had encountered.

There can be an overlap of reports regarding first and second doses of vaccine. And some of the components were subjected to selection and sensitivity biases. And finally, the studies were conducted with allergy specialist guidance that may lead to generalizability.

These findings suggest that it may be safe to re-vaccinate individuals with an immediate allergic reaction to the first COVID-19 vaccine dose in a supervised system to manage severe allergic reactions.

Finally, this study suggests that there is a low risk of a severe immediate allergic reaction associated with a second COVID-19 vaccine dose among persons who had a similar reaction to their first dose.

Source: Medindia