A leading medical scientist says Australians may need a fourth Covid vaccination shot by winter as case number begin to climb again in NSW and Victoria.
Professor Nathan Bartlett, from the University of Newcastle’s School of Biomedical Sciences and Pharmacy, said in an opinion piece published on Wednesday that the coming wave of the new Omicron BA2 variant means ‘the situation has changed again’.
Prof. Bartlett said a fourth shot will soon become necessary because third shot booster immunity is waning quickly.
‘It’s likely the coming surge means we’ll need a fourth Covid vaccine as we hit winter,’ Professor Bartlett wrote for The Conversation.
A fourth vaccine shot will soon become necessary because booster immunity is waning, it’s hard to tell how vulnerable we are and it’s too late for an Omicron-specific vaccine. Pictured is a woman getting a Covid-19 vaccination shot
NSW Health announced 30,402 new cases on Wednesday – a significant surge given cases had been hovering about the 9,000 mark.
About 10,000 of those cases were positive rapid antigen tests from Sunday and Monday that were accidentally not included in the figures for those days due to a data processing error and instead included in Wednesday’s numbers.
However the remaining 20,000 still resembles the highest number of cases in NSW since January 23.
Victoria likewise reported 9,426 new cases on Wednesday – the highest figure for the state since February 4.
The BA.2 Omicron sub-variant is on the rise in Australia, and NSW expects it to overtake the original Omicron strain and for cases to more than double by the end of April.
Early estimates suggest BA.2 is 25 to 40 per cent more transmissible than Omicron (BA.1), and is already taking off in countries including Denmark, Sweden and the UK.
Experts expect BA.2 to become Australia’s dominant strain in the coming months.
Though the Australian Technical Advisory Group on Immunisation (ATAGI) is not yet recommending fourth doses for everyone, people who are severely immunocompromised in Australia are already getting them.
Research published in the New England Journal of Medicine shows the immunity level provided by vaccines is quickly fading.
Vaccine effectiveness against Omicron dropped to around 45 per cent just ten weeks after a Pfizer third dose.
The available vaccines are based on the original Covid strain, but there have been many mutations since then, meaning Omicron is very different to the first strain.
Professor Bartlett said as research is only just beginning into BA.2, we don’t yet know how effective existing vaccines are against it.
But he notes that ‘three doses of a Covid vaccine are currently providing excellent protection from severe illness for most people’.
With winter – normally the height of cold and flu season – coming, most people will have had their third Covid vaccine dose more than four months ago, leaving them at greater risk of infection and needing a further boost to antibodies.
Professor Bartlett said that while millions of Australians have been infected with Covid – and some have been infected without knowing it – it is very hard for us to know what level of immunity the population has because of BA.2.
‘In this environment of uncertainty, allowing Australians to get a fourth dose would increase collective immunity and help us weather the rise of BA.2 during a winter where other cold and flu viruses are expected to make a comeback,’ he said.
There is also strong evidence that Omicron is good at evading the immunity we get from Covid vaccines as they were developed before Omicron existed.
A vaccine specifically designed for Omicron would, in theory, provide better protection, but by then BA.2 would already be dominant.
There is strong evidence that Omicron is good at evading the immunity we get from Covid vaccines as they were developed before Omicron existed. Pictured are people wearing face masks in Sydney
Professor Nathan Bartlett (pictured) said ‘managing Covid is becoming more complicated now’
A ‘universal or ‘variant-proof’ Covid vaccine could help, and are in development, but could take years, meaning existing vaccines are still the best option.
Nasal sprays could be another option, Professor Bartlett said, ‘because it’s very challenging for a vaccine injected into your arm to ward off a respiratory virus’.
His team has helped develop an immune-stimulating nasal spray that’s entering phase 2 clinical trials for Covid and flu, which works by boosting innate immunity in the tissue lining airways to attack the virus at the point of entry in the nose and throat.
‘Managing Covid is becoming more complicated now, and it’s impossible to predict where we’ll be a few months from now,’ he said.
Australia could face a tough winter with the BA.2 Covid-19 strain becoming dominant and influenza and colds spreading
***
Read more at DailyMail.co.uk