Ask the Pharmacist

Q. Someone told me I might now be eligible to receive a booster dose of the Covid vaccine and that I do not need a letter from my doctor to receive it. Is this true? Also, I was told that I would be getting either Comirnaty or Spikevax. Just which vaccines are they and how is it decided as to which one I’ll be receiving?

A. Many people are reluctant to change the brand of their COVID-19 vaccine, especially since some countries do not consider mixed doses to be fully vaccinated. We were pleased to hear the recent decision from the United States that they will, as of November the 8th, allow individuals vaccinated with mixed doses (as well as those that received 2 doses of the Astra Zeneca vaccine or an AZ dose along with an MRNA type dose) to enter their country. That has been a bone of contention among some of our customers that wished and pleaded for a booster dose to be able to have two of the “same” vaccine doses and thus qualify them to cross the border. At this point, the Ontario government does not allow booster doses for that purpose and continues to focus our vaccine supply on immunocompromised persons.

Third doses have been discussed in previous columns so we will not delve deeply regarding the specifics of such. However, there have been some changes as of late as to whom may be permitted to now receive the third dose due to the medications they take for other conditions that they are afflicted with. These medications carry a common trait of reducing the effectiveness of our immune system (which is really handy in controlling the symptoms of various autoimmune disorders such as rheumatoid arthritis, colitis and many others) thus making those who take them more susceptible to all viruses, COVID, of course, included. Some of the medications have been added are;

· Anyone who is taking a corticosteroid (prednisone, dexamethasone, methylprednisone) at a dose equivalent to 20mg prednisone daily for a minimum of two weeks.

· Antimetabolites such as methotrexate, cyclophosphamide, leflunomide, azathioprine, mycophenolic acid, mycophenolate mofetil

· Sulfasalazine or 5-Aminosalicylic Acid/mesalamine (Pentasa)

For an exhaustive list, visit and view Table 1 from the Ontario Ministry of Health,

Also, a referral letter from a healthcare provider is NOT required to receive a third dose if you are on one of the medications listed in Table 1. Simply having an existing (which will be in your pharmacy’s computer records) or new prescription for one of the said medications is sufficient enough proof. For anyone that falls into this category, the third dose may be given 8 weeks, or later, after the second COVID-19 vaccine dose.

Though many of us are referring to these third doses as booster doses, it is more accurate to refer to them as “additional” doses. This group of immunocompromised individuals likely had an inadequate response after the first two doses and hence require the third “additional” dose to get the same level of immunity as the rest of the population.

Individuals that live in a communal setting such as a long-term care home or retirement home are also eligible for an additional dose. In these settings, the third dose may be given 5 months after their second COVID-19 vaccine. Though they may not be immunocompromised because of a particular disease state or treatment, typically this clientele is in an older age bracket. Our immune systems typically wane as we age. That helps explain why some communal living residences are seeing a rise in COVID-19 cases, even among the fully vaccinated, as of late. It is not because the vaccines are not effective, as many anti-vaxxers may wish to believe, but rather the immune response in this group has diminished rapidly over time and likely never achieved the peak immunity status that a 30-year-old would have. As such, the third dose will hopefully elevate their protection up to that of a young, robust and healthy individual.

As for the vaccine names, most of us have referred to the two mRNA vaccines as Pfizer and Moderna. Now that both of them have officially been approved, it was time for them to actually give their vaccines a proper name rather than calling them by their company name. Therefore, the Pfizer vaccine is now named Comirnaty and the Moderna vaccine is now named Spikevax. Understandably, it may take us some time to get accustomed to those new names after so many months of referring to them by their company name. Keep in mind, the vaccine has not changed or been altered but rather just the name has changed. Not only have the mRNA vaccines been properly named, the AZ vaccine has also been named and is now referred to as Vaxzevria.

To decide which vaccine will be given as the third dose;

· For individuals that received two mRNA vaccines that were identical, they will receive the same vaccine for their third dose

· For individuals that received two mixed vaccines (two mixed mRNA or an AZ followed by an mRNA), the third dose will be the same as the second vaccine administered

· For individuals that received two AZ vaccines, either Comirnaty or Spikevax may be administered. It is not recommended to give an additional AZ vaccine since there isn’t enough evidence to promote their use for additional doses. There is also the increased risks of Vaccine-Induced Thrombotic Thrombocytopenia (VITT), Capillary Leak Syndrome (CLS) and Guillain-Barre Syndrome (GBS) that occur rarely with this brand of vaccine to consider. AstraZeneca’s Vaxzevria may be considered if an mRNA vaccine is contra-indicated or not accessible. A contra-indication would be having an allergy to one of the vaccine components or having experienced cardiomyopathy after a first dose of the mRNA.

For more information on this or any other topic, contact your pharmacist.