Wide-ranging calls for Australians to be provided with free rapid antigen tests (RATs) feature in the latest COVID-19 wrap by public health researcher Alison Barrett, who also shares a powerful case study of the global reach and impact of Twitter.
Urgent call for global “vaccines-plus” action
An open letter by a group of public health experts, clinicians and scientists, The BMJ, 3 January 2022
“The high transmissibility and degree of immune escape by the Delta and Omicron variants means sustained protective population immunity is unlikely to be achieved with the current vaccines based on the original strain,” authors of this open letter wrote, urging the World Health Organization (WHO) and national governments to adopt a global ‘vaccines-plus’ strategy to manage the pandemic.
Their recommendations for a ‘vaccine-plus’ strategy includes:
- A clear statement from national governments and the WHO to declare that SARS-CoV-2 is an airborne pathogen and the implications this has on preventing transmission.
- Promotion of the use of high-quality face masks, such as N95, P2, FFFP2, KF94 respirators, for indoor and other high-risk gatherings and settings.
- Advice on effective ventilation and air filtration.
- Standard criteria for relaxation or introduction of public health measures to reduce COVID-19, based on levels of community transmission.
- Support urgent measures for global vaccine equity.
‘Vaccines-plus’ is the policy advocated by the Director General of the WHO, Tedros Adhanom Ghebreyesus in his statement of 14 December 2021: “I need to be very clear: vaccines alone will not get any country out of this crisis. Countries can and must prevent the spread of Omicron with measures that work today. It’s not vaccines instead of masks, it’s not vaccines instead of distancing, it’s not vaccines instead of ventilation or hand hygiene. Do it all. Do it consistently. Do it well.”
Putting rapid antigen tests (RATS) to the test
The two types of tests to screen for SARS-CoV-2 are polymerase chain reaction (PCR) and rapid antigen test (RAT).
Each type of test detects a different part of the SARS-CoV-2 virus. The PCR test determines genetic evidence of the virus from a nasal and oral swab; and RATs look for antigens from the virus, via either a self-administered nasal swab or saliva/oral fluids.
“Antigens are substances that cause the body to produce an immune response – they trigger the generation of antibodies. These tests [RATSs] use lab-made antibodies to search for antigens from the SARS-CoV-2 virus,” Assistant Professor Nathaniel Hafer wrote in The Conversation.
PCR testing is the gold standard for diagnosing SARS-CoV-2, as this is generally better at detecting the virus than RATs. However, PCR-testing is labour intensive, expensive and results take a longer time to process.
People can perform RATs themselves at home (or anywhere) and it generally takes 15 to 30 minutes for the test to be completed and results produced.
RATs complement PCR-testing systems and enable people to get results quickly, prompting earlier isolation and reducing community transmission.
The WHO advises RATs are most reliable in areas where there is high community transmission (>5% test positivity rate).
Because of this, other than in some specific settings and situations (such as in healthcare and other essential workplaces), RATs have not been widely used in Australia until the past few months when cases started increasing rapidly.
Evidence for using RATs in the Omicron wave
RATs are more accurate when a person has a high viral load or is symptomatic, so doing them at the right time is very important for accurate results.
The Therapeutic Goods Association (TGA) recommends that the best time to test for SARS-CoV-2 using a RAT is within the first five to seven days from the beginning of symptoms.
Of the 22 RATs currently approved by the TGA for use in Australia, 16 are nasal swab tests. The remaining six brands require a saliva sample for the test.
At an OzSAGE online briefing this week, the slide below was presented to show the ranges of sensitivity and specificity in tests available. Presenters called for governments to ensure better educational materials, in diverse languages, to help educate the public about the range of tests available and how to use them.
They also urged the Government to act to ensure the most accurate tests were available to the public, rather than letting marketing determine which tests become most widely used.
A recent workplace study in America, not yet peer-reviewed, found that the Omicron variant was detected in PCR tests a median of three days before a RAT, confirming the sensitivity of PCR tests.
All rapid tests in the study produced false-negative results on the first two days after the first positive PCR test, even though nearly all participants in the study had a high infectious viral load.
Everyone in the study developed symptoms within two days after the first positive PCR test.
This information highlights that not only are symptoms developing quickly after infection with Omicron, but that a negative RAT, especially in the first one to two days after infection, does not necessarily mean absence of virus.
An additional sub-group analysis comparing daily saliva PCR, nasal swab PCR and nasal swab RATs found that the viral load of Omicron was detected in the saliva samples between one and three days earlier than in the nasal samples from both nasal PCR and nasal RAT, indicating the Omicron variant replicates in the throat prior to the nose.
Although the study has yet to be peer-reviewed and is based on a relatively small group of people (total thirty people), this finding supports those in a study completed in South Africa, where saliva PCRs detected Omicron earlier than nasal PCR tests.
More rigorous, long-term research is required to determine the efficacy and best use of RATs with Omicron variant.
However, the early evidence indicates RATs will work to detect the Omicron variant; saliva samples may detect Omicron variant earlier; and if a negative result is received on a rapid test, it may be a false-negative.
For a more detailed analysis of the workplace study, visit this Twitter thread.
Access and equity issues
Presently in Australia, RATs are hard to find, and predominantly at the individual’s own expense at around $10-$15 (or more) per test.
The Federal Government will provide up to ten free RATs in a three-month period to concession card holders, from 24 January. Individuals will need to collect them, with appropriate documentation, from participating pharmacies.
As demonstrated by the response to this picture I tweeted last week, showing how easy it is to access RATs in Holland, the Australian public are dismayed and frustrated about the limited access to RATs.
The responses also highlighted some of the issues faced by families, including people on low incomes or with chronic disease or with young children, in trying to access testing, either by PCR or RAT.
It became apparent that while some countries faced a similar situation as Australia, many people around the world had easy access to free and/or cheap RATs.
Another indication of the intense demand for rapid antigen tests in Australia is the high volume of enquiries to the TGA, as per this tweet by them on 19 January:
While acknowledging the rapid antigen test situation in Australia is part of a bigger and more complicated issue (see follow up thread with more information and context here), the response to my tweet is a great example of the power of Twitter and its ability to rapidly share information and engage people in meaningful conversations.
Risk of diabetes in children infected with SARS-CoV-2
Publication in US Centers for Disease Control and Prevention (CDC), by Barrett, CE et al., 14 January 2022
Data suggests that people younger than 18 who have had COVID-19 are more likely to develop diabetes than those without COVID-19 and those with an acute respiratory infection pre-pandemic.
Researchers at the CDC’s COVID-19 Emergency Response Team and Division of Diabetes Translation found this link in a retrospective analysis of American healthcare data between 1 March 2020 and 26 February 2021.
However, the study has a number of limitations, including that unfortunately, both type 1 and type 2 diabetes were labelled with a single code and the researchers were unable to determine accurately the difference in incidence between the two types of diabetes.
The researchers say their finding highlights how important it is to protect this group from COVID-19 with vaccination and other public health measures. The full study can be read here.
Importance of masks
Publication: Practical Indicators for Risk of Airborne Transmission in Shared Indoor Environments and Their Application to COVID-19 Outbreaks, Environmental Science & Technology, by Zeng, P et al., on 13 December 2021
As SARS-CoV-2 predominantly spreads by airborne transmission, many different public health measures are required to minimise the risk of becoming infected
Zeng and colleagues analysed well-documented data about different superspreading events to calculate the likelihood of being infected with the virus in different settings.
They found a higher likelihood of becoming infected in a high occupancy, indoor space that has poor ventilation, for a prolonged time without a mask (such as a nightclub or under-ventilated gym), than in a low occupancy, outdoor, well-ventilated space for a short duration while wearing a face mask.
Zeng and colleagues wrote:
...this analysis shows that mitigation measures to limit shared-room airborne transmission are needed in most indoor spaces whenever COVID-19 is spreading in a community.
Among effective measures are reducing vocalization, avoiding intense physical activities, shortening the duration of occupancy, reducing the number of occupants, wearing high-quality well-fitting masks, increasing ventilation, improving ventilation effectiveness, and applying additional virus removal measures (such as HEPA filtration and UVGI disinfection).
The use of multiple “layers of protection” is needed in many situations, while a single measure (e.g., masking) may not be able to reduce risk to low levels.”
The study can be read here.
Masks are an essential public health tool, and due to the highly infectious nature of the Omicron variant, they are now more important than ever for reducing risk of infection.
“It’s time to rethink and upgrade masks for you and your family,” they wrote. Cloth and surgical masks are more appropriate to “prevent the emission of large droplets” and are not as efficient at preventing aerosol transmission.
This article in The Guardian includes some useful tips on caring for and disposing of masks, and includes:
- Place your mask in a zip lock or paper bag when you’re not using it.
- Do not wear it longer than eight to ten hours.
- Dispose of in a bin; however, they are an environmental hazard and designated bins for masks and other PPE should be implemented in areas like shopping centres and aged care facilities.
- While cloth masks are not recommended for best protection against SARS-CoV-2, they are better than nothing. They should be washed after each day’s wear in 60 degree Celsius water.
Important initiative by ACOSS
Community sector calls for collaboration and decisive leadership from national cabinet to deal with COVID debacle, media release, 13 January 2022
In a letter to the National Cabinet, the Australian Council of Social Service (ACOSS) recommends the urgent creation of a “civil society COVID Rapid Response Group”, including ACOSS, public health experts, unions and business peaks to collaborate with government in responding to the current COVID-19 situation.
Data published by the Australian Institute of Health and Welfare indicates that people with low incomes were at four times the risk of dying of COVID-19 compared with other community members.
ACOSS CEO Dr Cassandra Goldie said: “We are now in a phase of rapid, widespread community transmission of COVID-19 and many people are missing out on the support they need. Government needs to reassess and respond with purposeful, active and decisive leadership.”
Read the letter to National Cabinet here.
Joint call for better support
Unions, Australian Aged Care Collaboration and Australian Nursing & Midwifery Foundation call for COVID-19 wage payment and support from defence forces.
“The escalating crisis in aged care has left services around the country reeling, putting care for older Australians at risk due to chronic staffing shortages. Older people are at risk of missing out on essential care because of this. Lockdowns are restricting many residents to their rooms as services work to keep them safe,” authors of a joint media statement wrote.
They request the Federal Government deploys the Australian Defence Force (ADF) to provide emergency assistance and support to overwhelmed aged care facilities across the country.
In addition, to secure the workforce, they request a COVID-19 wage payment for all staff, and immediate access to RAT and PPE supplies.
“Aged care staff are working hard to provide care in very challenging circumstances and with limited resources. They are on the frontline of the fight against COVID-19, protecting the most vulnerable in our society. They must be resourced and enabled to win this fight,” they wrote.
Unions leaders issue demands
A meeting of national union leaders on Monday produced this statement, calling for new COVID-safe plans from all employers, free RATs, and emphasising the “devastating impact the latest COVID wave is having on the health and incomes of working people”.
Healthcare workers especially are overburdened and exhausted, “experiencing the full brunt of this wave of sick people,” they wrote.
They highlighted some recommendations to keep all employees safe at work:
- Where working from home is not an option, free RATs, upgraded masks and improved ventilation for employees are required.
- Union movement to do everything possible to ensure safety of workers and community, which may include banning unsafe work practices.
- Free RATs to be provided to everyone to limit the spread of virus and keep everyone safe.
Hospitals are in serious trouble
Ed Yong, The Atlantic, 7 January 2022
“The health-care system will continue to pay these costs long after COVID hospitalisations fall. Healthcare workers will know, but most other people will be oblivious – until they need medical care and can’t get it.” Yong discusses the burden of COVID-19 on American hospitals, health workers, and patients.
Calling Omicron Mild is wishful thinking
Katherine J. Wu, The Atlantic, 13 January 2022
“All of this has allowed a deceptively reassuring narrative to take root and grow: Omicron is mild…Much of our Omicron problem can be traced back to a false binary: That the variant is less of a danger too often gets misconstrued as the variant is not a danger at all.” – Wu provides an in-depth discussion about the problems with calling Omicron “mild”.
When will this COVID wave be over? 4 numbers to keep an eye on and why
Adrian Esterman, The Conversation, 14 January 2022
Professor Esterman discusses the four numbers that are required to more accurately measure and track the pandemic:
1) the number of new daily COVID-19 cases, which is impacted by different case reporting methods in each state and the introduction of self-administering rapid antigen tests.
2) the effective reproduction number (Reff), the average number of people each positive person infects. To stop an outbreak, the Reff needs to be below one.
3) percentage of positive tests from all COVID-19 tests taken.
4) number of people hospitalised.
How to learn from our COVID history (no, not with a royal commission)
Stephen Duckett, Pearls and Irritations, 19 January 2022
“It is important to remember the good bits,” of Australia’s response to the pandemic, Duckett wrote. “But not everything went perfectly. For most of the pandemic the Federal Government has been in the denial stage of the grief cycle.”
“We should approach the task of learning from what went wrong during the pandemic with a system improvement lens, rather than an individual punitive focus.”
Alison Barrett is a Masters by Research candidate and research assistant at University of South Australia, with interests in public health, rural health and health inequities. Follow on Twitter: @AlisonSBarrett. Croakey thanks her for providing this column as a probono service to our readers.
See previous editions of the COVID wrap.