Pfizer say three jabs may be needed to protect against Omicron

Pharmaceutical giant Pfizer has revealed just two doses of its Covid vaccine may not provide enough protection against the Omicron variant.

Two shots of the Pfizer-BioNTech Covid-19 vaccine may not be enough to protect against the Omicron variant, new laboratory studies have revealed.

On Wednesday, the pharmaceutical giant Pfizer announced the results from an initial laboratory study has indicated three doses of the vaccine may be needed to create enough antibodies “neutralise” the Omicron Covid-19 variant.

The results showed that sera, a fluid obtained from separating blood, from individuals who received two doses of the current Covid-19 vaccine exhibited, on average, more than a “25-fold reduction in neutralisation titers against the Omicron variant compared to wild-type”.

Researchers say this indicates that two doses of the vaccine “may not be sufficient to protect against infection with the Omicron variant”.

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Three doses of the Pfizer vaccine may be needed to protect against the Omicron variant. Picture: Kena Betancur/AFP

A transmission electron micrograph of SARS-CoV-2 virus particles, isolated from a patient. Picture: AFP

However, Pfizer said it is still likely that vaccinated individuals will be protected against severe forms of the disease, with authorities closely monitoring the real world effectiveness against Omicron.

The study found the protection from antibodies increased 25-fold when a third dose of the Pfizer vaccine was administered.

This third dose provides a similar level of protection against Omicron as two doses provides against other variants that have emerged previously.

“Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from this preliminary data that protection is improved with a third dose of our vaccine,” Albert Bourla, Pfizer Chairman and CEO, said.

“Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of Covid-19.

Ugur Sahin, M.D., CEO and Co-Founder of BioNTech, said the introduction of robust vaccination booster campaigns globally will help increase protection against the Omicron variant.

“Broad vaccination and booster campaigns around the world could help us to better protect people everywhere and to get through the winter season,” he said.

“We continue to work on an adapted vaccine which, we believe, will help to induce a high level of protection against Omicron-induced COVID-19 disease as well as a prolonged protection compared to the current vaccine.”

The results from this study are preliminary, with both Pfizer and BioNTech saying they will collect more laboratory data and “evaluate real-world effectiveness” of the vaccine against the Omicron variant.

The news comes after the two companies revealed last month they were developing an Omicron specific vaccine.

The first batches of the Omicron-based vaccine are expected to be ready in less than 100 days, pending regulatory approval.

Omicron spreads to new Aussie states

Cases of Omicron have now been confirmed in multiple Australian states and territories, including NSW, the ACT, Qld, Victoria and the Northern Territory.

On Wednesday, Victoria confirmed the state’s first Omicron case in an overseas traveller.

“Following whole genomic sequencing, the case in hotel quarantine reported yesterday has been confirmed as having the Omicron variant,” the Department of Health said.

Concerns are also growing over two additional “likely” Omicron cases recently detected in the Victorian community.

“Two cases have returned results with S gene dropout – a signature of the Omicron variant,” the department said.

“None of these cases are linked to international travel and their source of acquisition is under investigation.”

The Omicron variant has spread to multiple Australian states and territories.

The two suspected cases are located in the outer Melbourne cities of Casey and Brimbank.

Also on Wednesday, Queensland health authorities declared they had detected a “first in the world” strain of the Omicron variant.

The state recorded no new community cases on Wednesday but two Omicron infections previously detected in hotel quarantine in Cairns and Brisbane had been reclassified following the scientific development.

The new variant was detected in a traveller who arrived in southeast Queensland from South Africa, which Health Minister Yvette D’Ath said had been named by the World Health Organisation as “Omicron-like”.

“Remember, it’s only been days since this has become an issue for Australia and other countries,” she said.

“And now, today, we are standing here announcing a new version of Omicron and it’s a first in the world.”