Case numbers are alarming in NSW, but there is room for optimism

Limitations when it comes to testing and reporting positive cases, and a lack of regular prevalence surveys at the population level, undermine efforts to characterize the severity of Omicron’s severity and to determine the trajectory of this wave. Whether diagnosed cases are half or one-fifth of the true number of infections, and how this proportion changes, are key elements in determining when the current wave is likely to peak.

If the official figures are closer to one-fifth of the true number of infections, rapidly rising infection-based immunity – especially in younger groups who are more likely to transmit the disease – should provide some approximation to flock immunity. A large majority of undiagnosed Omicron cases would make the relatively lower severity of this variant compared to Delta even more striking.

Paramedics at Nepean Hospital Sunday.

Paramedics at Nepean Hospital Sunday.Credit:Dean Sewell

Other factors that potentially slow down the spread of Omicron are restrictions on hospitality, albeit late in their introduction, fewer large household gatherings now Christmas and New Year are over, and the fact that people move less, given the holiday season. The rollout of the third dose of the vaccine could help, but its impact on slowing transmission is likely to be modest so far, given its slow pace, the fact that booster shots were initially aimed at groups at higher risk of serious illness but lower risk of transmission (e.g., the elderly or those with underlying medical conditions), and given the shot provides only partial protection against infection with the Omicron variant.

Opportunities have been lost to characterize and understand the Omicron wave. To inform public health policy, more steps should be taken to ensure better monitoring of subsequent waves of the Australian epidemic.

First, there is a need for improved collaboration on COVID-19 testing and reporting between jurisdictions. The delayed introduction of mandatory rapid antigen testing reporting is just one example of a lack of coordination.


Second, investing in surveillance at the population level is a priority. The UK, an international leader in COVID-19 research, has a randomized home study of more than 100,000 people that gives participants regular inoculation tests to determine the incidence of active infection and to take blood samples for both vaccine and natural levels of infection immunity. Such data are invaluable in determining major wave infection denominators and the trajectory and distribution of the spread.

Thirdly, a comprehensive and ongoing initiative to evaluate the impact of Australian COVID-19 vaccination, including declining immunity, is crucial.

As we move into the third year of the pandemic, there is cause for optimism. Although we are likely to see subsequent waves driven by new varieties – Pi, Rho and Sigma are the next in line – our protective wall through vaccine and infection immunity continues to build and treatments should continue to improve.

Omicron has undoubtedly given rise to greater individual awareness of COVID-19. So many people in NSW have now either become infected or had close experiences with someone infected. This will help society better understand this disease. Widespread access to rapid antigen testing will also support early diagnosis in future waves and coupling to care when needed. While 2022 may not see the end of the pandemic, we will be far better equipped to respond effectively because of this recent outbreak.


Greg Dore is an epidemiologist and infectious disease physician at Kirby Institute, UNSW.

All the information on this website – – is published in good faith and for general information purpose only. does not make any warranties about the completeness, reliability, and accuracy of this information. Any action you take upon the information you find on this website (, is strictly at your own risk. will not be liable for any losses and/or damages in connection with the use of our website.