Anaphylaxis and Coronavirus Disease 2019 Vaccine: A Danger Relationship?

Luciana Kase Tanno; Mariana Castells; Marco Caminati; Gianenrico Senna; Pascal Demoly


Curr Opin Allergy Clin Immunol. 2021;21(5):411-417. 

In This Article

Abstract and Introduction


Purpose of review: Anaphylactic reactions reported after Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) RNA vaccines were expected to be more frequent in atopic subjects and attributed to its polyethylene glycol component.

Recent findings: Anaphylaxis to SARS-CoV2 RNA vaccines is no more frequent than in any vaccine and direct proofs for the role of its polyethylene glycol component are lacking.

Summary: Vaccines against coronavirus disease 2019 (COVID-19) are an essential global intervention to control the current pandemic situation. Anaphylactic reactions have rapidly been reported after SARS-CoV2 RNA vaccines. This risk is now measured at 2.5–11/1 000 000 in the context of vaccine safety surveillance programs and only one case was documented to be due to polyethylene glycol. Suggestions for its role are indirect. The COVID-19 vaccination is rolling out vastly and surveillance programs are key to monitor severe adverse reactions, such as anaphylaxis. Anaphylaxis due to vaccine is extremely rare and specific cases should receive individualized investigation and care, highlighting the key role of allergists in the vaccination programmes.


SARS-COV2 Vaccination: Essential to Control the Coronavirus Disease 2019 Pandemic

The SARS-COV2 Vaccination Evolution. According to the World Health Organization's (WHO) report, globally, as of 22 May 2021, there have been 165 771 430 confirmed cases of coronavirus disease 2019 (COVID-19), including 3 437 545 deaths.[1] Long-term sequelae manifestations and serious complications have been reported among COVID-19 survivors, including individuals who initially presented with mild acute illness.

Since the start of the COVID-19 outbreak, scientists started a global run to reach safe and effective vaccines, in what we can consider as a true scientific evolution. There are no doubts that the vaccine against COVID-19, combined with other preventive barrier measures, is an essential global intervention to stop the pandemic, save lives and reduce widescale social disruption.

The United Kingdom, Bahrain, Canada, Mexico, USA, Singapore, Oman, Saudi Arab, Kuwait and European Union began their vaccination programme with the BNT162b2 (Pfizer-BioNTech) vaccine, whereas USA and Canada also started the mRNA-1273 (Moderna) vaccination programme in mid-December 2020.

Broader COVID-19 vaccination programs have been launched in many countries in early 2021. On 11 December 2020, the US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for Pfizer-BioNTech COVID-19 vaccine.[2,3] This followed by the authorization of Moderna mRNA-1273 vaccine for use by other regulatory agencies, such as the European Commission, UK Medicines and Healthcare Products Regulatory Agency (MHRA), Israel Ministry of Health among others[3–6] and several other vaccines in many other countries.

As of 21 May 2021, a total of 1 488 242 899 vaccine doses have been administered according to the WHO report. Globally, in the past week (10–16 May 2021), the number of new cases and deaths continued to decrease with just over 4.8 million new cases and just under 86 000 new deaths reported; a 12 and 5% decrease, respectively compared to the previous week.[1] Efforts are ongoing to vaccinate as many people as possible.

First Reports of Anaphylaxis and Their Consequences. As of 23 December 2020, first doses of Pfizer-BioNTech COVID-19 vaccine had been administered in the United States and 4393 (0.2%) adverse events reported, and among these, 175 cases of severe allergic reactions, including anaphylaxis.[2] Further surveillance data reported for the United States suggested a rate closer to 1:200 000 doses for the Pfizer-BioNTech vaccine and 1:360 000 for the Moderna vaccine.[2,4]

In the United Kingdom, after the two recipients of Pfizer-BioNTech vaccine experienced anaphylaxis reported personal history of prior anaphylaxis,[7] the UK regulators issued an advisory statement, which listed prior anaphylaxis to vaccine, medicine or food as a contra-indication,[8] generating an initial concern that patients with atopic diseases might be more likely to develop allergic reactions to COVID-19 vaccines. This recommendation was initially followed by the US Food and Drug Administration (FDA) and the US Centers for Disease Control and Prevention (CDC), but later changed their recommendations.[9] On 30 December 2020, the UK Minister of Health reviewed the previous recommendations, limiting the contra-indications to patients who reacted to the first injection or who had a confirmed allergy to any component of the vaccine, as it has long been recommended for any vaccine. However, it generated considerable fear worldwide by the population and many inquiries from health professionals dealing with COVID-19 and vaccination programs. As a consequence, the international and national allergy academies have produced guidelines and recommendations to support patients and healthcare professionals according to current evidence-based data.[10–12]

The introduction of a new vaccination is always the subject of debate, even inducing reactions of rejection. This problem echoes the significant public mistrust of the vaccine programme, mistrust amplified by the internet, false rumors, opportunistic colleagues and deleterious media frenzy. More than ever the science of real data must prevail and communication must be mastered and scientific.