Can Comirnaty (Pfizer-BioNTech COVID-19 vaccine) and Fluarix Quad (influenza vaccine) be co-administered?

From the Guidelines

Comirnaty (Pfizer-BioNTech COVID-19 vaccine) and Fluarix Quad (influenza vaccine) can be co-administered during the same visit, with no need to separate these vaccines or schedule them on different days. According to the most recent guidelines, influenza vaccines can be administered simultaneously with or any time before or after administration of the currently available COVID-19 vaccines 1. When administered together, the vaccines should be given at different injection sites, typically in different arms or at least 1 inch apart if using the same limb. This co-administration is safe and does not diminish the immune response to either vaccine. In fact, getting both vaccines during the same visit can improve vaccination compliance and ensure timely protection against both COVID-19 and seasonal influenza. The immune system is capable of responding to multiple antigens simultaneously, and there is no evidence that receiving these vaccines together increases side effects or reduces effectiveness. Common side effects from either vaccine include injection site pain, fatigue, headache, and muscle aches, which typically resolve within a few days.

Some key considerations for co-administration include:

• Injectable vaccines that are given concomitantly should be administered at separate anatomic sites 1.
• Vaccines that are administered at the same time as influenza vaccines that might be more likely to be associated with local injection site reactions should be given in different limbs, if possible 1.
• Data are limited regarding coadministration of vaccines with nonaluminum adjuvants, including COVID-19 vaccines, but available evidence suggests no significant safety concerns or decreased immunogenicity 1.

Overall, the benefits of co-administering Comirnaty and Fluarix Quad during the same visit outweigh the potential risks, and this approach can help improve vaccination compliance and protect against both COVID-19 and seasonal influenza.

From the Research

Co-administration of Comirnaty and Fluarix Quad

• The co-administration of COVID-19 and influenza vaccines, such as Comirnaty (Pfizer-BioNTech COVID-19 vaccine) and Fluarix Quad (influenza vaccine), has been studied in several research papers 2, 3, 4, 5, 6.
• According to a study published in the Journal Pharmaceuticals (Basel, Switzerland), co-administration of COVID-19 and influenza vaccines has been shown to be safe, with a reactogenicity profile similar to that of either vaccine administered alone 2.
• Another study published in the Journal Vaccine found that co-administration of a quadrivalent influenza vaccine and the Pfizer-BioNTech mRNA COVID-19 vaccine led to enhanced immune responses to influenza virus and reduced immune responses to SARS-CoV-2 in naive mice 3.
• A study published in bioRxiv found that concurrent administration of COVID-19 and influenza vaccines enhances Spike-specific antibody responses 4.
• A similar study published in Open Forum Infectious Diseases found that concurrent administration of COVID-19 and influenza vaccines enhances Spike-specific antibody responses and yields higher and more durable SARS-CoV-2 neutralizing antibody responses while maintaining responses against influenza 5.
• Additionally, a study published in Vaccine found that dual vaccination with COVID-19 and seasonal influenza vaccines is associated with reduced COVID-19 infection and disease severity 6.

Safety and Immunogenicity

• The safety and immunogenicity of co-administering Comirnaty and Fluarix Quad have been studied, with results indicating that co-administration is safe and can induce robust antibody responses against both infectious agents 2, 3.
• The immune response towards four influenza strains and the SARS-CoV-2 spike protein in co-administration groups is generally non-inferior to that seen in groups receiving either vaccine alone 2.
• However, some studies have found that co-administration can have a slightly negative impact on SARS-CoV-2 binding and neutralization titers 3.

Public Health Implications

• The co-administration of Comirnaty and Fluarix Quad can simplify vaccine delivery and increase vaccination uptake 2.
• Public health authorities have advocated for co-administration, and several combination vaccine candidates are in (pre)-clinical development 2.
• However, hesitancy towards vaccine co-administration or combination vaccines is a multifaceted phenomenon and may be higher than the acceptance of either vaccine administered separately 2.