Covid-19 News Updates

Victorian authorities urge partygoers to come forward for testing as COVID-19 cluster grows

Victorian health officials now have 15,000 primary and secondary contacts linked to the current COVID-19 outbreak and yet again saw record testing rates yesterday, but they are also well aware that not everyone is checking into venues with QR codes.

With the state now in its first day of lockdown after four new cases were reported yesterday taking the current cluster to 30, the number of exposure sites continues to rise but there are five in particular that the Department of Health and Human Services (DHHS) is homing in on.

DHHS Deputy Secretary Jeroen Weimar says it is believed one of the new cases identified yesterday contracted the virus at the The Sporting Globe in the beachside suburb of Mordialloc between 6:15pm and 9:45pm on Sunday, 23 May.

"We now see the significant risk, particularly at those social venues - the bars and clubs that our exposure list has - and we're very keen to ensure that people who have been to those places at those times come forward very quickly," Weimar said.

These five venues include The Sporting Globe in Mordialloc at the stated times, as well as the following:

• The Three Monkeys bar, Prahran - 9:10pm-11pm on Saturday, 22 May and 12:30-2am Sunday, 23 May.
• Somewhere Bar, Prahran - 10:30pm-1am on the night of Saturday, 22 May and Sunday, 23 May.
• The Palace Hotel, South Melbourne - 5:45-6:45pm on Saturday, 22 May.
• The Local, Port Melbourne - 1:30-3:30pm on Friday, 21 May.

"If you've been to those locations, you've been out partying with somebody who was COVID-positive at the same time in that space," he said.

"Our real focus over the next day or two is going to be on identifying any additional people that ignored the current QR code systems - if you did not check in, we really need you to come forward to make sure that we can get you tested and isolated."

Updated at 11:29am AEST on 28 May, 2021.

Urgent call for vaccinations as seven-day snap lockdown confirmed for Victoria

Unlike previous lockdowns when people were allowed four reasons to leave the home, Victorian authorities have today announced a critical fifth exception for the stay-at-home measures that will take effect at 11:59pm tonight - getting vaccinated.

With 150 exposure sites across Greater Melbourne and other parts of the state relating to the latest COVID-19 cluster that has now risen to 26, as well as the identification of 10,000 contacts connected to them, Acting Premier James Merlino confirmed an anticipated one-week lockdown for Victoria.

"Unless something drastic happens, this will become increasingly uncontrollable. This vaccine rollout has been slower than we hoped - that is a fact," Merlino said.

"If more people were vaccinated, we might be facing a very different set of circumstances than we are today. But sadly, we are not. If we make the wrong choice now, if we wait too long, this thing will get away from us."

After a record-breaking 40,411 people got tested yesterday and contact tracers were able to identify and lock down, first, second and third rings of contacts within 24 hours, the concerning issue is that the current variant transmits much more quickly than others that Australia has had to handle.

Merlino said the serial interval, meaning the time it took between the onset of symptoms between first and secondary cases, was sometimes averaging just over a day.

"Now to put that in some perspective, the usual transmission is about five to six days. In some of these cases, within a day it's been transmitted," he said.

"And in just 24 hours the number of cases has doubled," he said, also noting one of the recent cases is in serious condition in an intensive care unit (ICU).

What are the changes?

Victoria's seven-day lockdown is expected to last until 11:59pm next Thursday, however Merlino said if they could be eased earlier then that will be done. He gave the following five reasons why people would be allowed to leave the home once the lockdown comes into effect:

• Shopping for necessary goods and services;
• Authorised work or permitted education;
• Exercise with a two-hour maximum with one other person;
• Caregiving, compassionate and medical reasons;
• Getting vaccinated.

Merlino said vaccines were "the only pathway through this pandemic", and to help the effort the state-run vaccination facilities will now be opening their doors to the 40-49 age bracket for Pfizer/BioNTech COVID-19 vaccinations.

Victorians will not be able to go outside of a 5km perimeter from their homes, unless their nearest shops are further away than that.

"Masks must be worn everywhere, indoors and outdoors, anywhere other than your home unless an exemption applies," he said.

"There are to be no visitors to your home, other than an intimate partner, but single bubbles will be permitted. If you live alone, you can make a bubble with another person.

"There are to be no public gatherings."

He said restaurants, pubs and cafes were allowed to be open for takeaway only, while essential retail could be open such as supermarkets, food stores, petrol stations, banks, bottle shops and pharmacies. Other retail stores can provide click and collect.

Childcare and kindergartens will be open as per the last circuit-breaker lockdown, approved professional sporting events will proceed with no crowds, and schools will move to remote learning except for vulnerable children and the children of authorised workers.

Hotels, clubs, TABs and casinos will be closed.

"We know that this is going to be particularly difficult for businesses and events," Merlino said.

"I really encourage everyone if you are eligible, get vaccinated. The reason why we are dealing with this outbreak today is because of a hotel breach in South Australia.

"That is not a criticism, it is just a fact. We've had breaches in hotel quarantine right around our country. The only way through this pandemic is everyone getting vaccinated as quickly as you are eligible and for the Commonwealth to agree to an alternative quarantine arrangement, particularly for high risk individuals."

"If we had an alternative to hotel [quarantine] for this particular variant of concern, we would not be here today. If we had the Commonwealth's vaccine program effectively rolled out, we would not be here today talking about these circuit-breaker restrictions that we must impose to keep our community safe."

The Victorian Government is also establishing six new testing sites today in Brighton, Cheltenham, Ascot Vale, East Reservoir and East Coburg.

States and Territories react 

Western Australia has just announced its border to Victoria is closed, following South Australia's restrictions on travellers coming from Greater Melbourne that was implemented last night. 

Anyone who has arrived in WA since 16 May must get tested and go into isolation until they receive a negative result. Anyone wishing to arrive who has been to Victoria since May 16 is no longer allowed to enter Western Australia.

At 6:30am today, the Essendon AFL team who arrived in WA yesterday all returned negative results.

"Our thoughts are with the people of Victoria and we have every confidence Victoria will quickly get on top of this," WA Premier Mark McGowan said.

Overnight, the Northern Territory designated VIC as a COVID-19 hotspot, meaning any travellers into the top end must now complete 14 days of mandatory quarantine at their own expense on arrival.

Tasmanian Premier Peter Gutwein will establish all of Victoria as a high-risk area from 2pm AEST today. Anyone who arrives before then can enter unless they have been to Whittlesea LGA or VIC exposure sites.

Only people designated as essential travellers will be permitted to enter Tasmania after 2pm, but they will still have to complete two weeks of quarantine.

Queensland has declared Victoria a hotspot, so anyone who arrives in the Sunshine State from Victoria after 1am tonight will need to enter hotel quarantine. Anyone who has been in Victoria within the past 14 days, or arrives from Victoria before the cut-off tonight, will still need to observe the same stay-at-home rules as Victorians while in Queensland.

"On behalf of Queenslan  we wish Victoria all the very best, and I know that the next seven days we're going to be with you every step of the way," Queensland Premier Annastacia Palaszczuk said.

Queensland's Chief Health Officer Dr Jeannette Young said there had been an increase in testing rates, and she urged anyone with symptoms to get tested.

New South Wales has issued a stay-at-home order to anyone travelling to the state from Victoria, effective 4pm AEST today.

The measure means anyone arriving in NSW who has been in VIC since 4pm today must remain at their home or place of residence in NSW for the seven-day duration of the lockdown.

People will only be permitted to leave their places of residence for limited reasons, including shopping for essential items, medical care, caregiving, outdoor exercise, and essential work or education, if you cannot do it from home.

For NSW residents living along the VIC border, the seven-day stay-at-home requirement will only apply to people who have been outside the border region in VIC from 4pm today.

"People subject to the stay-at-home measures in Victoria should not be travelling to NSW unless they are permitted to do so," NSW Health.

Updated at 11:43am AEST on 27 May.

NSW Health issues COVID-19 alert for Riverina sports club

NSW Health has issued an alert for an event of concern in Victoria close to the state's border, which was attended by a NSW sporting club based in the western Riverina town of Tooleybuc.

Last night authorities announced they were urgently contacting people from the club who had attended a sporting event in Cohuna, Victoria on Saturday 22 May from 12 to 5pm. It is understood that both football and netball matches were played at the event.

"This event was attended by a confirmed case of COVID-19. Anyone who attended is requested to immediately self-isolate and await further advice from NSW Health," the authorities said in the alert.

"NSW Health is working to set up increased capacity for testing in the area and thanks the community for their cooperation."

People in NSW are advised to postpone non-urgent travel to Greater Melbourne and Bendigo, as Victorian health authorities continue to investigate the COVID-19 outbreak.

Click here for the full list of exposure sites in Victoria, which is constantly being updated and includes several location in Greater Melbourne and Bendigo, including the Melbourne Cricket Ground, many hospitality venues and retail stores.

Marvel Stadium in Docklands has also recently been added to the list of sites, as well as Stratton Finance in Port Melbourne, popular Italian restaurant Criniti's Southbank.

Updated at 7:42am AEST on 27 May 2021.

SA border to Greater Melbourne closed from tonight

Effective from 6pm today, anyone from Greater Melbourne will not be permitted to enter South Australia as the southern state responds to a growing outbreak of COVID-19 in the Victorian capital.

Returning South Australians will be permitted to cross the border after 6pm today, but they must complete two weeks of self-quarantine on arrival back home.

The new border restrictions come after Victoria reported six new locally acquired cases of COVID-19 today, bringing the total number of infections connected with this latest outbreak to 15.

In addition to the border closure, SA Premier Steven Marshall announced anyone who has returned from Greater Melbourne since 20 May will need to arrange a COVID-19 test and isolate until a negative result is received. They will also be required to get tested on days five and 13 from their arrival into SA.

Further, travellers from Bendigo into SA will also need to abide by new COVID-19 rules. While they are permitted to enter the state, they must get tested on days one, five and 13 on arrival into SA and isolate until a negative result is received.

"Australia is doing extraordinarily well in tackling the coronavirus compared to just about any jurisdiction in the world, so we've got to work together to make sure that we don't have any further outbreaks," SA Premier Marshall said.

"Our thoughts are with everybody in Victoria, particularly those in Melbourne."

SA's decision to slam the border shut makes it the only Australian state or territory to take such action thus far.

Western Australia currently requires all travellers arriving from Victoria to be tested for COVID-19 and isolate until a negative result is returned.

The Northern Territory is asking only those who have been to any Victorian Tier 1 public exposure sites to undertake 14 days of quarantine in their home or a suitable place on arrival. Those who have been to Tier 2 sites must get get tested and self-isolate until a negative result is received.

The City of Whittlesea local government area has been declared a COVID-19 hotspot by the Queensland Government, meaning anyone who has been to that area and travelled to QLD must go into hotel quarantine.

New South Wales has asked people to postpone non-urgent travel to Victoria while the outbreak is investigated, and Tasmania requires anyone who has been to a venue of concern to isolate and call the Public Health Hotline on 1800 671 738 to organise testing.

Updated at 5.44pm AEST on 26 May 2021.

Six new locally acquired cases in Victoria, infected person attended AFL match at MCG

The Victorian Department of Health has confirmed 11 new locally acquired cases of COVID-19 in the last 24 hours, bringing the total number of infections connected with the latest outbreak to 15.

The 11 new cases include the five reported yesterday, with the 15th case notified to VIC Health just prior to a press conference this morning from Acting Premier James Merlino. That case will be included in tomorrow's figures.

Merlino said all the confirmed cases could be connected at this point in time.

"These cases are linked and that's a good thing," said Merlino.

"But we are very concerned by the number and the kind of exposure sites."

The announcement coincides with an alert from VIC Health that a person infected with COVID-19 attended an AFL match at the Melbourne Cricket Ground (MCG) on Sunday 23 May.

According to the Department of Health, the positive case attended the Collingwood vs Port Adelaide game at the MCG on Sunday 23 May, sitting in Zone 4, Level 1 of the Great Southern Stand.

People seated in that zone - those with a bay between M1 & M6 on their match ticket - will be contacted directly with advice to get tested and isolate until negative.

"The AFL and the MCG have prepared for this moment. There's been extensive work over a long period of time between our public health team and stadium management," Merlino said.

"We're very grateful that we had the data on hand very shortly after it came to our attention so we could contact all of those affected."

A number of venues and businesses have been added to the official public exposure sites list as the outbreak unfolds, including in regional Victoria. 

The Hairfolk Salon in Bendigo is considered a Tier 2 exposure site for people who visited between 9.40am and 10.10am on Saturday, May 22.

In addition, the Axedale Tavern in Axedale, just outside of Bendigo, is a Tier 1 exposure site for people who attended the pub between 11.45am and 1.30pm on 23 May.

Inner-Melbourne exposure sites have also been added to the official list which is regularly being updated here.

The Three Monkeys Bar on Chapel Street has announced on its Instagram page that a positive COVID-19 case attended the venue on Saturday night, between 9.10 pm to 1.30am.

RELATED: The pressure is on for Australia to accept the coronavirus really can spread in the air we breathe

Victorian Health Minister Martin Foley said many of the recently listed Tier 1 sites were of concern, in particular:

• Circus Bar at 199 Commercial Road, South Yarra, between 1:30am and 4:15am on Sunday May 23
• The Three Monkeys bar at 210 Chapel Street, Prahran, between 9:10pm and 11:00pm on Saturday May 22 and 12:30am and 2:00am Sunday May 23
• Somewhere Bar at 181 Chapel Street, Prahran, between 10:30pm and 1:00am on Saturday May 22

The news comes after Victoria introduced new COVID-19 restrictions at 6pm yesterday, limiting visitors to households and requiring face masks to be worn indoors. These rules will also apply to people leaving Greater Melbourne to other parts of the state. Schools and workplaces will remain open.

There are no more changes to restrictions today, but Merlino said he would not rule out tougher rules for Victorians if the situation worsens.

"I cannot rule out taking further action," he said.

"The next 24 hours are going to be critical if we're going to make any changes beyond the changes we made yesterday."

In response to this latest outbreak, Federal Opposition Leader Anthony Albanese criticised the Federal Government's handling of the hotel quarantine program on Twitter, and called on the PM to establish a dedicated quarantine facility in every state and territory in Australia.

His criticism comes after this latest outbreak in Victoria is believed to be connected to a COVID-19 leak from Adelaide's hotel quarantine system, whereby a man in his 30s left quarantine in South Australia but developed symptoms and ultimately tested positive to the virus while in Melbourne.

Updated at 9.33am AEST on 26 May 2021.

New Zealand pauses travel bubble with Victoria as new cluster rises to nine cases

Quarantine-free travel between New Zealand and Victoria has been paused while investigators search for the source of a COVID-19 outbreak in Melbourne's north.

It comes as the Whittlesea City COVID-19 cluster grows to nine cases today, with the ABC reporting Victoria has recorded another four new COVID-19 infections this afternoon. Several more exposure sites have also been listed by Victorian health authorities, including stores at the Highpoint Shopping Centre.

The four are in addition to a man in his 60s who tested positive and was linked to the first case reported yesterday. Victorian health officials introduced new COVID-19 restrictions in response to the growing cluster, including mandatory mask wearing indoors and limits on home gatherings.

The ABC reports this afternoon's four new cases are all family contacts of the man in his 60s.

The travel bubble pause, enforced by New Zealand health authorities, will come into effect from 7.59pm NZT and be in place for 72 hours initially.

"While the case announced today is not unexpected as a contact of a case announced yesterday, New Zealand officials have assessed that the most cautious option is to pause the travel bubble with Victoria as there are still several unknowns with the outbreak," the New Zealand government said.

"The Government understands the disruption this will temporarily cause affected passengers. It was a close call but the correct one given the current unknowns. The decision follows the travel bubble framework."

Health authorities across the ditch are concerned that an epidemiological link has not yet been established connecting some of the recent cases in Melbourne.

"Whole genome sequencing has identified that the cases reported yesterday are closely linked to a previous case identified in the community in Wollert on 11 May after leaving managed isolation in South Australia," the New Zealand government said.

"An epidemiological link has yet to be determined between these cases and there is currently no known link between people in the current outbreak and any of the exposure sites from Wollert."

Anyone in New Zealand who has been at a location of interest in Melbourne at the specified time should contact Healthline on 0800 358 5453 as soon as possible for advice on isolating and testing. 

Further, anyone who has visited Melbourne since 11 May should monitor for symptoms and seek advice from Healthline if any symptoms develop.

New Zealand put a pause on the travel bubble with New South Wales earlier this month due to an outbreak of COVID-19 in Sydney in order to give authorities time to search for a missing link of infection.

That pause lasted for just three days after New Zealand health officials determined the risk to public health from NSW travellers was low. 

More exposure sites listed

Victorian health officials have updated the list of Tier 1 and Tier 2 exposure sites in Melbourne, including a number of stores at Highpoint Shopping Centre, a McDonald's in Clifton Hill and an ALDI in Epping. 

The new exposure sites are as follows:

• McDonald's Clifton Hill - 22 May from 6-7pm (Tier 1)
• ALDI Epping - 23 May from 6-7pm (Tier 2)
• Chemist Depot Epping, Pacific Epping Shopping Centre - 23 May from 11.15am-12pm (Tier 2)
• Smiggle, Highpoint Shopping Centre - 20 May from 5.55-6.30pm (Tier 1)
• Kidstuff, Highpoint Shopping Centre - 20 May from 5.20-5.55pm (Tier 1)
• Ishka, Highpoint Shopping Centre - 20 May from 5.45-6.20pm (Tier 1)
• Lush Cosmetics, Highpoint Shopping Centre - 20 May from 6.05-6.35pm (Tier 1)
• Toyworld, Highpoint Shopping Centre - 20 May from 5.30-6.20pm (Tier 1)
• Bamboo House, Melbourne - 21 May from 11-11.50am (Tier 1)
• Adams Reserve Playground, Preston - 23 May from 2.15-3.45pm (Tier 2)
• ALDI Preston South - 23 May from 3.45-4.25pm (Tier 2)

The new exposure sites are in addition to already announced locations including:

• Futsal Brunswick - 23 May from 9-10am (Tier 2)
• Nando's Epping (Dalton Rd) - 19 May from 8:30-9:20pm (Tier 1)
• Epping North Shopping Centre - 22 May from 4:45-5:50pm (Tier 2)
• House and Party (store) - 22 May from 5:15-5:50pm (Tier 2)
• Woolworths Epping North - 22 May from 4:45-5:45pm (Tier 1)
• Urban Diner Food Court, Pacific Epping Shopping Centre - 23 May from 1:15-2:30pm (Tier 2)
• Shell Coles Express Reservoir - 18 May from 3:15-4:15pm (Tier 2)
• B.T. Connor Reserve - 21 May from 8-11:30pm (Tier 2)

Updated at 3.19pm AEST on 25 May 2021.

One new case in Melbourne as more exposure sites listed

UPDATE [4.17pm AEST 25 May]: The Whittlesea City COVID-19 cluster has since grown by four more cases. Read more here.

Acting Victorian Premier James Merlino has advised of a fifth case in the latest Whittlesea City COVID-19 outbreak in Melbourne's north - a man in his 60s who has also been linked to the first case reported yesterday.

"Importantly, he reports being symptomatic before case one developed symptoms, meaning this could be a possible source case," Merlino said.

"But of course a full investigation and interview process is underway - it has to run its course.

"Following early investigations, this case, like the four that we announced yesterday, has not identified any link to any of the exposure sites from the Wollert case two weeks ago."

However, the acting Premier explained genetic sequencing for this outbreak has been completed and in that sense it is closely related to the Wollert outbreak, which occurred with a returning traveller who became COVID symptomatic after completing quarantine in Adelaide.

In response to the situation and on the advice of health officials, from 6pm tonight private gatherings in Greater Melbourne will be limited to a maximum of five visitors, public gatherings will be capped at 30 people, and face masks will be required indoors.

These rules will also apply to people leaving Greater Melbourne to other parts of the state. Schools and workplaces will remain open.

Melburnians and travellers who have been in Greater Melbourne recently are encouraged to keep an eye on the official list of exposure sites, which following interviews with the latest case is expected to grow.

Since Highpoint Shopping Centre in Maribyrnong and 'Jump! Swim Schools' at Bundoora were added yesterday afternoon, more venues and locations have been added including:

• Futsal Brunswick - 23 May from 9-10am (Tier 2)
• Nando's Epping (Dalton Rd) - 19 May from 8:30-9:20pm (Tier 1)
• Epping North Shopping Centre - 22 May from 4:45-5:50pm (Tier 2)
• House and Party (store) - 22 May from 5:15-5:50pm (Tier 2)
• Woolworths Epping North - 22 May from 4:45-5:45pm (Tier 1)
• Urban Diner Food Court, Pacific Epping Shopping Centre - 23 May from 1:15-2:30pm
• Shell Coles Express Reservoir - 18 May from 3:15-4:15pm (Tier 2)
• B.T. Connor Reserve - 21 May from 8-11:30pm

Anyone who has been to a Tier 1 site at the stated times must get tested immediately and quarantine for 14 days from exposure, while anyone who has attended Tier 2 sites at the listed times needs to also get tested and isolate until they receive a negative result. 

Updated at 10:17am on 25 May 2021.

Shopping centre and swim school listed as new Melbourne COVID-19 exposure sites

One of Australia's largest shopping centres and a swim school in the suburb of Bundoora have been listed as Tier 1 exposure sites for COVID-19, as further positive cases have been reported in the Victorian capital.

Following this morning's news of two likely coronavirus-positive cases in Melbourne's north, tests of family members - one adult woman and a child - have also come back positive, taking the number of new locally-acquired cases to four. 

The epicentre of locations has moved slightly south from Epping where the majority of previous venues were concentrated, with a case having Highpoint Shopping Centre in Maribyrnong on 20 May from 5pm to 8pm, as well as 'Jump! Swim Schools' at Bundoora on 21 May between 8:55am and 10:15am.

Both locations have been given a Tier 1 designation but with different conditions attached.

Anyone who visited the swim school at the stated times must get tested immediately and quarantine for 14 days from exposure.

Those who visited the shopping centre must also get tested, however they have been directed to isolate until further notice rather than going into quarantine.

"I can advise that one of the individuals lives within the wastewater catchment areas that produced the strong detection that we reported last Friday," Victorian Health Minister Martin Foley said.

"There is as yet no indication that these individuals are linked to any exposure sites from the previous alert case, but investigations are ongoing.

"I do indicate there are likely to be more sites as further investigations continue."

In response to the evolving situation, NSW Health has issued a health alert for Melbourne, urging people who have attended the listed exposure sites at the stated times to contact the agency immediately on 1800 943 553

People arriving in NSW from the Greater Melbourne area are reminded that they must complete a declaration confirming they have not attended one of these venues of concern.

"Declaration forms can be completed within the 24-hour period prior to entering NSW, or on entry to NSW," NSW Health said.

"People who have been in the Whittlesea Local Government Area should not visit residential aged care facilities, or hospitals unless seeking medical attention.

"The Whittlesea LGA includes the suburbs and rural localities of Beveridge, Donnybrook, Doreen, Eden Park, Epping, Humevale, Kinglake West, Lalor, Mernda, Mill Park, South Morang, Thomastown, Whittlesea, Wollert, Woodstock and Yan Yean."

The Queensland Government has declared anyone already in the state or arriving before 1am on 26 May, who has been at the Melbourne Tier 1 exposure sites at the stated times, must quarantine at their home or other suitable accommodation until 14 days have passed since their exposure.

Anyone who has been to the relevant sites and the listed times and arrives in Queensland after 1am on 26 May, will need to enter Queensland Government-arranged quarantine accommodation.

Meanwhile in Tasmania, any recent arrivals into the state from Victoria who have been at any of the listed exposure sites must immediately self-isolate and contact the Public Health Hotline on 1800 671 738 to organise testing.

Further, anyone who has been to any of the locations of concern will not be permitted to enter Tasmania unless approved as an essential traveller.

Updated at 4:48pm AEST on 24 May 2021.

Victoria reports two likely COVID-19 cases in Melbourne's northern suburbs

Victoria's Department of Health and Human Services (DHHS) is conducting a full investigation into two likely positive COVID-19 cases in Melbourne's northern suburbs, around two weeks after the state's last outbreak began.

The department was made aware of the issue this morning, and it is currently understood that both individuals are connected.

"A full investigation is underway into these results, and initial public health actions are being put in place while both individuals isolate and are urgently tested," the DHHS said in a statement.

"We will communicate any specific public health actions the community needs to undertake as soon as possible when investigations and case interviews are complete."

The announcement follows an intensification of testing in the Epping area after authorities realised they had posted Woolworths Epping as an exposure site, when a case earlier this month had in fact visited the Woolworths at Epping North.

Authorities have not confirmed whether the latest cases can be traced back to the earlier case, whereby a man in his 30s left quarantine in South Australia but developed symptoms and ultimately tested positive to the virus while in Melbourne.

Click here for an updated version of Victoria's exposure sites, and anyone with symptoms is encouraged to get tested.

Updated at 11:28am AEST on 24 May 2021.

Have researchers developed an effective COVID-19 treatment? Maybe, but we need human trials

The world is now 18 months into the COVID-19 pandemic and we've yet to find a single drug that can stop the virus. At best, we can treat the effects of the virus through oxygen therapy for those who can't breathe, and with drugs that reduce the inflammation associated with the infection.

But an Australian-United States research team, led by Griffith University's Menzies Health Institute, have shown promising results in their mouse trials of a new treatment for COVID-19.

The technology is based on "short interfering RNA", which prevents the virus from replicating inside human cells. They found a 99.9% drop in the number of virus particles in the mice they studied.

The researchers hypothesise the drug could be injected into patients daily for up to five days, for example for sick patients in hospital, or as a once-off if someone has just been exposed to the coronavirus; however, there's no data on this specifically, so it's speculative for now.

While the results are very promising, the technology has only been tested in mice. Human clinical trials will take some time to complete before we know whether a drug will be approved by the government.

How viruses work

Viruses are tricky to treat because they are biological molecules made of the same types of materials as the human body. Virus particles are just packets of information on how to make more virus, encoded in a molecule called "ribonucleic acid" or RNA (although some contain DNA instead) within a protein coating.

Once a virus particle penetrates into a cell, it either hijacks the machinery of the cell to make copies of itself, or in some cases, has its RNA copied into the host cell's DNA. Either way, the cell becomes a manufacturing facility making hundreds and thousands of copies of the virus.

So the best way to stop a virus is to stop its RNA information being copied and transcribed by the cell.

We already have drugs capable of doing this for specific viruses. A drug called PrEP (pre-exposure prophylaxis) is available as a prophylactic against infection with HIV and the development of AIDS. A prophylactic can prevent a disease before it takes hold in the body.

The PrEP medicine works because the two active ingredients it contains, tenofovir and emtricitabine, block a molecule called reverse transcriptase which the virus needs to be replicated. Unfortunately, neither drug works to block COVID-19.

Short interfering RNA

Unlike PrEP, the new technology is particularly clever because it uses a molecule called short/small interfering RNA or "siRNA" to prevent the reading and copying of the virus information. This siRNA was specifically designed to recognise a sequence of the coronavirus' own RNA that is common across COVID-variants.

This means the siRNA can seek out and lock onto the viral RNA because it perfectly complements it, regardless of the COVID-19 strain. When it locks with the virus RNA, the viral information becomes trapped and can't be copied, or it causes the RNA to be cut and degraded.

At this point there is no virus production, and our immune system can just mop up the small number of virus particles floating around the body.

To prove their technology, the researchers enclosed their siRNA in lipid nanoparticles, which are essentially tiny fat-like particles. Without this protective coating, the siRNA would be destroyed in the blood stream before it could lock onto the virus. Lipid nanoparticles are also used in the formulation of the Pfizer and Moderna COVID-19 vaccines.

With the protective nanoparticle shell, the siRNA could then be delivered via a water-based injection into veins.

When the researchers administered the siRNA to mice that had been infected with COVID-19, they found the mice didn't lose as much weight when compared with untreated mice. Weight loss was an indicator of how sick the mice were.

The researchers also found a 99.9% drop in the number of virus particles in the mice.

On occasion, when biological molecules are injected into the blood stream, this can trigger a severe allergic reaction called anaphylaxis. Importantly, the researchers found their siRNA didn't trigger an immune response in the mice, and therefore will be unlikely to cause anaphylaxis.

So as well as being effective, the technology appears to be relatively safe.

Will this drug be available soon?

As promising as the results are, we shouldn't get our hopes up that a drug will be available any time soon. Data derived from animal tests doesn't always translate to success in humans. Often, the way an animal's body processes a drug can be different from the human body, and it ends up being ineffective.

Also, animal tests are just the first step in a long regulatory process to prove a drug works and is safe. Even with accelerated clinical trials and fast-tracked assessment from governments, an approved drug is still a year or more away.

Nial Wheate, Associate Professor of the Sydney Pharmacy School, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.