Omicron: Experts answer the most Googled booster jab questions

These are the questions Australians ask most online about the booster jabs. We asked two of the nation’s leading experts for answers.

As Omicron cases surge, Australians after being urged to get their Covid-19 booster jabs to protect themselves from the new variant.

With the need for the extra virus protection that a third shot provides. Australians are turning to Google to ask the big questions.

We put the top booster vaccine questions Australians are asking on the internet search engine according to data from Google Trends Australia, to virologist Professor Sarah Palmer, Co-Director, Centre for Virus Research, The Westmead Institute for Medical Research and Professor Catherine Bennett, Chair in Epidemiology at Deakin University.

WHEN CAN I GET MY COVID-19 BOOSTER SHOT?

Professor Palmer: As of January 4, you are eligible for a booster vaccine if you are 18 years of age or older and have had your second dose of your original Covid-19 vaccination at least four months ago.

Professor Bennett: After January 4, you can ask for your booster as soon as you are four months out from your second dose. You are already eligible if you had your second dose at the end of July. At the end of January the interval drops to three months, so many younger adults will become eligible then.

IS MODERNA OR PFIZER BOOSTER BETTER?

Prof Palmer: Boosters from both vaccines have been reported to increase antibodies against Omicron. These boosters will provide added protection from infection and serious disease.

Prof Bennett: The Moderna booster dose is half the strength of that used for the first two doses, but still shows a great boosting effect and is slightly ahead of Pfizer in early studies of vaccine effectiveness against symptomatic infection, whether you had AstraZeneca or an mRNA for your primary course.

People reported a stronger reaction to the early doses of Moderna, so some might prefer to switch to Pfizer, but the reduced concentration in the booster will make the effects similar to Pfizer and both mRNA boosters shots are reported to be generally less reactogenic then the second dose.

HOW DO I BOOK MY COVID BOOSTER?

Prof Palmer: A Covid booster can be easily booked with your GP. Additional access to boosters will be provided in the future.

Prof Bennett: If you search “book Covid booster” online you will find the links to that allow you to organise an online booking vis the Australian Government site, pharmacies, or your state health website.

WHO CAN GET THE BOOSTER COVID VACCINE?

Prof Bennett: At this stage, anyone who is 18 or older, and who had a second dose five months or more ago, is eligible. On January 4, the interval drops to four months. People over the age of 18 who are severely immunocompromised are also eligible for a third dose to help top up their immune response as part of an extended primary course.

WHICH COVID VACCINE BOOSTER SHOULD I GET?

Prof Palmer: Boosters of Pfizer and Moderna are available, and you can receive either one regardless of the vaccine you had for your first two doses. Both the Moderna and Pfizer boosters have been shown to be effective in providing protection against, infection, severe disease, and death from Omicron.

Prof Bennett: Both Moderna and Pfizer are excellent at boosting your protection from serious illness back up to well over 90 per cent, even with Omicron, and also reducing your chances of having any symptomatic infection from any strain. Some early data from the UK shows this protection from any infection might wane a bit over time, but it’s too early to know, and it still halves the risk after 10 weeks which not only protects you, but will help reduce the spread in the community.

HOW LONG DOES IT TAKE FOR A BOOSTER SHOT TO BECOME EFFECTIVE?

Prof Palmer: Both Moderna and Pfizer have shown their boosters become effective against the Omicron variant at least one month after the booster. However, the actual time frame these boosters become effective could be earlier than one month, but more studies are required to prove this is the case.

Prof Bennett: Like all doses, it takes a week or two to get the full benefit of the boosted immune response that the vaccine triggers.

Both Moderna and Pfizer are excellent at boosting your protection from serious illness back up to well over 90 per cent, even with Omicron. Picture: AFP

WHY DO YOU NEED A BOOSTER SHOT FOR COVID?

Prof Palmer: Studies have shown that antibody levels after the second vaccination decline with time making them less effective for protecting a person from infection with SARS-CoV-2. A booster reinvigorates your antibody response. Getting a booster is especially important now as Omicron becomes the dominant variant because this variant is more infectious. Boosting your antibody levels will provide you added protection against this highly infectious variant.

Prof Bennett: At the moment in Australia, we have two Covid major outbreaks causing us problems – Omicron is spreading faster and causing overall infection rates to rapidly climb, but Delta is still around and probably responsible for most hospitalisations in both NSW and Victoria. The booster doses lift vaccine performance against both variants to levels that are higher than those first weeks after the primary course.

For Delta, that means a 10-fold lower risk of having an infection. Importantly boosters also restore protection from any Omicron symptomatic infections that had waned after the primary course. This extra reduction in infection risk might not last as well against Omicron as Delta, but if it buys us at least 10 weeks, then it will make a big difference helping to control how quickly this variant moves across the country.

IS THE PFIZER BOOSTER SAFE?

Prof Palmer: Globally, tens of millions of persons have received their booster shots, proving these boosters are safe.

Prof Bennett: The safety data on the boosters is good and suggests the reaction to the booster dose is less than the second dose. The Israeli data which is the most comprehensive so far as they started rolling out Pfizer booster doses first, reported that the side effects were more mild than those seen with the second dose. Moderna data are showing the same story, and as their booster dose is half the original dose used, that’s what we would expect.

ARE THE BOOSTER SIDE EFFECTS WORSE?

Prof Palmer: The data collected on booster shots suggest that the side effects caused by the booster are very similar to the symptoms a person experienced after their initial Covid-19 vaccination and in some instances the side-effects are even milder.

Originally published as Omicron: Experts answer the most Googled booster jab questions