Experts weigh up fourth Covid vaccine dose

Chief Health Officer Brett Sutton said the BA. 4 and BA. 5 sub-variants now accounted for about 40 per cent of virus waste­water detections in Victoria, and would become the most common strain over coming weeks. Victoria recorded 7317 new cases of COVID-19, and 24 deaths on Monday.Chief Health Officer Brett Sutton said the BA. 4 and BA. 5 sub-variants now accounted for about 40 per cent of virus waste­water detections in Victoria, and would become the most common strain over coming weeks. Victoria recorded 7317 new cases of COVID-19, and 24 deaths on Monday.Experts blamed the more infectious new variants, which can evade immunity gained from the vaccines and earlier infections, along with a rise of other respiratory viruses (RSV).“BA.4/BA.5 has now become the dominant strain in wastewater detections in major population centres including Greater Geelong and Melbourne,” Professor Sutton said on Monday night.“The Department of Health anticipates the prevalence of BA.4/BA.5 in Victoria is likely to result in an increase in cases – including reinfections – and hospital admissions and deaths.“This is because the strain has a greater ability than BA.2 to evade immunity provided by vaccination and earlier Covid-19 infection.Professor Sutton said there was no evidence the BA.4/BA.5 sub-lineages caused more severe disease at this stage, but the Department of Health was monitoring the situation.The Australia Technical Advisory Group on Immunisation (ATAGI) will discuss expanding the fourth dose for under 65s when it meets tomorrow which Infectious Diseases physician Paul Griffin said made sense.Professor Griffin said ATAGI had expanded the eligibility last month to include the immunocompromised and those at higher risk of getting ill from Covid even if they are under the age of 65.“We have more infectious sub-variants where our vaccine protection is waning,” he said.NED-6507-Covid-Booster-Guide“I think particularly as we go through what looks to be a very significant wave of transmission, increasing access to that fourth dose would make sense.”Prof Griffin said infection immunity was not guaranteed against the two strains but there was no evidence they are more severe than previous iterations.