MANILA — Worried about getting an allergic reaction to COVID-19 vaccines? The Philippine Society of Allergy, Asthma and Immunology (PSAAI) said Filipinos should be more concerned about being infected with the virus.

Dr. Rommel Lobo, PSAAI president, told ABS-CBN News that Filipinos should realize there is greater risk being infected with and dying from COVID-19 and that it is important for Filipinos to understand that scientific studies have shown that approved vaccines are safe and effective.

In an 11-page position paper released this week, the PSAAI discussed in length the possible side effects of COVID-19 vaccines.

It said that anaphylaxis, the only contraindication for some COVID-19 vaccines, “is rare with an estimated incidence of 11.1 per 1 million doses in mRNA COVID-19 vaccines.” These are vaccines from Pfizer and Moderna that instruct the human body to produce spike proteins to elicit an immune response against COVID-19.

Who should NOT receive a COVID-19 vaccine?

According to the PSAAI and documents of the mentioned vaccine manufacturers, those who immediately experience an allergic reaction after receiving the first dose of a COVID-19 vaccine should no longer be given a second dose.

Patients who also experience anaphylaxis, which causes difficulty in breathing and rapid heartbeat due to chemicals such as polyethylene glycol and polysorbate, should also not receive certain COVID-19 vaccines.

Polyethylene glycol, also used in colonoscopy preparation and laxatives, is among the ingredients of mRNA vaccines. It is used to coat the messenger RNA in Pfizer’s vaccine.

Meanwhile, polysorbate, found in vascular graft materials, surgical gels and PEGylate medications, can also be found in non-replicating adenovirus vector vaccines and protein subunit vaccines. Examples of COVID-19 vaccines using the adenovirus vector are AstraZeneca’s and Sputnik V of Russia’s Gamaleya Institute.

The vaccines of Novavax and Clover Biopharmaceuticals are considered protein sub-unit vaccines or those containing only a part of the COVID-19 virus.

Also needing further evaluation by an allergist are patients who experience immediate allergic reaction to other vaccines or injected therapy in case they are allergic to PEG or polysorbate.

Who can receive COVID-19 vaccines?

The PSAAI said the following special groups can also receive COVID-19 vaccines, but they might also need to consult a doctor:

• Patients with allergic reactions to food, inhalant allergens, insects, latex, oral medications not related to vaccines;
• Patients with immunodeficiency and autoimmune disease such as Guillain-Barre Syndrome, Bell’s palsy (although more studies need to be done)
• Patients with well-controlled asthma and inhaled corticosteroids and those with allergic rhinitis on intranasal corticosteroids

What should you do on the day of vaccination?

Lobo said those dealing with allergies should refrain from taking antihistamines before being vaccinated.

“It has never been recommended to give prophylactic antihistamine when you are given vaccination,” he said.

“Kasi it may just mask the symptom and magkaroon ka ng delayed anaphylaxis. Instead na lumabas within a few minutes baka a few hours after. Maggugulo lang ’yung situation. Kawawa ’yung patient, madedelay ang treatment n’ya.”

(Because it might mask the symptom and delayed anaphylaxis could occur. Instead of just a few minutes, it could surface a few hours after. The situation will just be more complicated. Pity the patient, the treatment will just be delayed.)

All patients should also be observed for 30 minutes at the vaccination center to ensure they won’t develop any allergic reaction.

What should be done in case of anaphylaxis?

And in the rare chance that a patient experiences anaphylaxis, health workers should administer the drug epinephrine.

Lobo said 0.3 to 0.5 mL of epinephrine should be injected in the thigh muscles for fast absorption of the body.

“This is why we need to educate all the vaccinators properly to identify and prepare for contingencies,” he said.

Lobo assured the public that the Philippines has enough supply of epinephrine, which he called a “wonder drug.”

“Epinephrine, when you inject it, it does not only reverse the symptoms that you will see when they have anaphylaxis. But also it will prevent progression of the symptoms,” he said.

Are there other allergic reactions during vaccination?

Lobo said that most allergic reactions linked to vaccination is actually not because of the microbes or microorganisms in the vaccine.

“There are vaccines that have been grown in yeast. Meron silang konting yeast na pwedeng mag-cause ng reaction o kaya gelatin pwede rin ’yun, or ’yung rubber ng bakuna di ba pina-puncture mo ’yun (from the vial or synringe). Merong ibang rubber may natural latex. Eh kung allergic ka sa latex, du’n baka pwede ka mag-react,” he explained.

(There are vaccines grown in yeast. They have a bit of yeast that may cause reaction or gelatin. That can also be a trigger, or the rubber that is being punctured. There is a type of rubber that has natural latex. If you are allergic to latex, then you can also have a reaction.)



Asked if people allergic to eggs should also avoid vaccines, as suggested by a viral but unverified post on social media, Lobo said that while some vaccines contain egg protein the amount of protein in each vaccine is not enough to cause an allergic reaction.

COVID-19 vaccines being developed are also not egg-based. Some vaccines that include egg protein or are egg-based are certain flu shots.

What about other side effects?

The PSAAI emphasized that reactogenic reactions, such as the inflammation of the vaccine site, is not the same as allergic reactions.

“Leaking of these mediators and products of inflammation into the circulation can also result in systemic side effects. Most systemic post-vaccination reactions are mild to moderate in severity, which include headache, fatigue, malaise, muscle pain, chills, fever and vomiting,” the position paper read.

For these reactions, supportive case is given in the form of cold compress or pain killers.

Lobo emphasized that COVID-19 vaccines that have been approved by regulatory agencies such as the Philippine Food and Drug Administration benefit the general public “and this benefit will far outweigh the adverse reaction to COVID-19 vaccines.”