COVID booster shots and 3rd doses – what’s the deal?

October 28, 2021 by Lisa Bywaters0

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There’s been a lot of talk in the media recently about boosters and third doses of the COVID-19 vaccines. And the nurses on our Help Line are certainly taking lots of calls about it! So we thought we’d answer some of your questions about this next step in the vaccination rollout.

Honestly, most of us thought that once the majority of Australians were double vaxed, it was smooth sailing ahead. That everything was sorted. Job’s done. Time to ‘get on the beers’ and return to normality. 🍻🥂

But this virus is tricky, and we’re still learning so much about it. Including how to protect ourselves from it.

Fortunately, we can look overseas for information. With Australia’s vaccine rollout months behind countries like the UK, US and Israel, we can learn a lot from their experiences and the data they’re collecting.

We know that after two doses of the vaccines, healthy people have a greatly reduced risk of developing severe COVID or ending up in hospital. Which is fantastic news. Yay for vaccines!

However, we’re seeing that some people with weakened immune systems (immunocompromised) have caught COVID, even though they’re fully vaccinated.

Although we don’t know exactly why this happens, it appears that people who are immunocompromised have a varied response to the vaccine. They do gain immunity, but it’s generally not to the same extent as the general population. And how much immunity they gain depends on their underlying health condition and the medications they’re using.

That’s why the Australian Technical Advisory Group on Immunisation (ATAGI) has recently recommended a 3rd dose of the vaccine to severely immunocompromised people so that they can reach a level of immunity that’s protective. You can check out their list of immunocompromising conditions and therapies here. The Australian Rheumatology Association has also updated their COVID-19 information to include information about third doses. And if you want to know if you need to get a 3rd dose – because the information can be a little confusing – talk with your GP or specialist about your situation.

It’s worth pointing out that the use of additional doses to increase the vaccine’s effectiveness in immunocompromised people isn’t a new thing. It happens with other vaccines, for example, the annual flu shot to boost immunity to the influenza virus. Instead of one flu shot, some people require two.

When it comes to the general population – again using overseas experiences and data – we’re seeing that about 6 months after the 2nd vax, the protection from the vaccines seems to be waning.

A booster shot may be needed if immunity to the virus does start to decrease. The Therapeutic Goods Administration (TGA), in consultation with ATAGI, has assessed the Pfizer vaccine for safety and effectiveness as a booster. As of 27 October 2021, it was provisionally approved for use in those aged 18 and over. The first in line to get it will be those who received their vaccines firsts – way back in February 2021 – so that’s aged care residents, frontline health and quarantine workers. The government is waiting on further advice from ATAGI as to when the rest of the population will receive boosters.

Booster shots may also be required in the future as we see different variants of the virus emerge. Again, as we see with the annual flu vaccination, it’s tweaked each year to keep up with changes to the influenza virus. This may be what happens with the COVID vaccine.

At this stage, the Pfizer vaccine is the only one put forward as a booster. So what does that mean if you received a Moderna or AstraZeneca vaccine for your first two doses?

We’re not sure. Several studies are investigating this very question. It’s possible that mixing different vaccines might broaden your protection. But the research is ongoing, and it’s just too early to say. So it’s a matter of ‘watch this space’.

Finally, it’s essential to recognise that being vaccinated doesn’t stop people from getting COVID. But it significantly reduces the risk of severe disease and hospitalisation. That’s why we need to be vigilant and do all the COVID-safe things we’ve been doing since this whole thing started:

  • wash your hands
  • cover your coughs and sneezes
  • wear a mask (when required)
  • physical distance
  • check in
  • stay home when sick
  • get tested
  • and stay safe.

Contact our free national Help Line

If you have questions about managing your pain, your musculoskeletal condition, treatment options, mental health issues, COVID-19, telehealth, or accessing services be sure to call our nurses. They’re available weekdays between 9am-5pm on 1800 263 265; email (helpline@msk.org.au) or via Messenger.

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