What’s the deal with booster doses?

Jamie Dalton MPS vaccinating a patient

As pharmacists approach a huge COVID-19 vaccination milestone this week, curious patients inquire about boosters.

After little more than 2 months of administering COVID-19 vaccines, pharmacists have delivered 949,600 doses to patients across Australia. 

The Moderna vaccine has continued to dominate, with 25,700 doses administered in the last 24 hours compared to 14,600 of AstraZeneca.

Victoria is leading the Moderna charge, with 71,400 doses administered since its Spikevax rollout began. The state is fast approaching its vaccination target of 70%, with 53% of residents now fully vaccinated. Due to the vaccination boost, restrictions may be lifted earlier than anticipated on 24 October.

Moderna booster queries on the rise

As Spikevax continues to roll out in pharmacies and more countries introduce boosters, patients are increasingly inquiring about extra COVID-19 vaccine doses, pharmacists report. 

Since rolling out Spikevax in her Mackay Queensland pharmacy 2 weeks ago, Karalyn Huxhagen FPS has seen an influx of patients wanting to book in for either a Moderna vaccine booster dose, or a second dose of Moderna after receiving a different vaccine.

‘One patient wanted a booster shot because he read in the British media that a [dose] of [an mRNA vaccine] combined with AstraZeneca showed improved efficacy,’ Ms Huxhagen told Australian Pharmacist.

Reports on Pfizer’s waning efficacy is also behind some booster inquiries.

‘One elderly gentleman who had two Pfizer [doses] through his doctor rang the other day and wanted a booster of Moderna, based on what he had seen in the media about Pfizer waning quicker,’ Ms Huxhagen said.

When explaining that booster doses are not currently recommended in Australia, she makes sure she speaks to patients ‘clearly, calmly, in words they understand’.

‘The majority of the people who are asking these questions are frightened, their health literacy is not amazing and they are a little confused by the different reports,’ she said.

Ms Huxhagen explains that COVID-19 is a global problem, and so far local data has not indicated a reduction in immunity after two COVID-19 vaccine doses.

‘I talk in words like “drops away” rather than “decreasing immunity”,’ she said. 

Ms Huxhagen also discusses local data on hospitalisations, which are primarily in the unvaccinated.

‘I talk about the fact that we don’t have evidence that [many] patients are ending up in hospital [after] they have had their two doses, so that tells us that the immunity is not dropping away.’

From an international standpoint, pharmacists could point out that while recent research in the New England Journal of Medicine on the effectiveness of mRNA vaccines in healthcare workers shows that efficacy reduces after some months, this is in relation to symptomatic infection. 

‘This effectiveness is against symptomatic infection, not against hospitalisation or death, which is much higher,’ said Associate Professor Nicholas Wood, Associate Director, National Centre for Immunisation Research and Surveillance, in a recent Healthmed lecture.

According to new research published this month in The Lancet, the Pfizer vaccine is 90% effective against hospitalisation for up to 6 months.

ATAGI advice

Vaccinating the eligible population is the immediate key priority to convey to patients before booster shots come onto the agenda.

High primary COVID-19 vaccine coverage is expected to have the largest impact on protection against severe disease both directly (by direct protection) and indirectly (by prevention of transmission),’ the Australian Technical Advisory Group on Immunisation (ATAGI) said last month.

It’s also important for patients to understand that the ATAGI is considering the timing of booster doses to ensure protection is provided during future outbreak peaks.

For now, a small cohort of patients are expected to require a booster dose, including those who are immunocompromised. Later this month, ATAGI expects to release advice about people – including those who are severely immunocompromised – who may need three doses in their first course of vaccination. As well, it expects release advice about booster doses for the general population.

Remain vigilant

Pharmacists should ask patients for photo ID and a Medicare card, and check the Australian Immunisation Register before administering the vaccine.

‘Even though they’ve filled in the form, I still have a set conversation with them to make sure that the answers ticked on a form are actually true,’ Ms Huxhagen said. ‘You just have to be careful.’

Large-scale myocarditis study

New research in JAMA Internal Medicine has found that acute myocarditis post-mRNA vaccine is exceedingly rare. Out of 2.4 million adults (aged over 18) who received a Pfizer or Moderna vaccine, 15 cases of myocarditis were recorded. These cases were all in men aged 20–32 years old, and each patient recovered.

On the other hand, the rate of myocarditis in unvaccinated patients was 5 times higher (75 out of 1.6 million patients), affecting both men and women equally with a median age of 52.

‘Vigilance for rare adverse events, including myocarditis, after COVID-19 vaccination is warranted but should not diminish overall confidence in vaccination during the current pandemic,’ the study authors wrote.

Must know Spikevax advice for pharmacists

With more patients expecting to visit community pharmacies for COVID-19 vaccines now that Moderna is widely available, an adequate vaccine booking program is crucial. 

Pharmacists should adopt the national vaccine booking system by connecting to the Vaccine Clinic Finder (VCF). 

Tonight, PSA is hosting a webinar to equip immunising pharmacists with the necessary skills to successfully roll out the Moderna vaccine and ensure their online booking service and appointment availability is listed on the VCF.

The webinar will focus on vaccine specific facts, real-world experience and practical information in order to ensure pharmacists fulfil the requirements of informed consent and patient education, particularly post-vaccination. 

It will feature health experts and practitioners with experience in the use of the national VCF and booking system.  

To register for the webinar, which will be held at 7:00 pm AEDST, click here.