Global COVID-19 testing shortages threaten variant surveillance

The steady hum of PCR laboratories and rapid antigen test production lines that once defined the early pandemic years has faded into a quieter rhythm across much of the world. As governments pivot away from emergency funding and populations grow weary of swabbing noses, the infrastructure that monitors SARS-CoV-2 is contracting at a moment when virologists warn that new immune-evasive sublineages may be spreading silently in undertested regions.

Diagnostic capacity has not disappeared, but it has thinned. In dozens of countries, free community testing has ended, reimbursement schemes have tightened, and at-home rapid tests are increasingly the only option for people who suspect infection. The downstream effect is a dangerous blind spot. Fewer samples flowing into laboratories means fewer viral genomes being sequenced, and that scarcity of data leaves health agencies reactive rather than proactive when the next concerning variant emerges.

The shrinking diagnostic net

Between 2022 and early 2024, global testing volumes fell by an estimated 70 to 80 percent from their Omicron-era peaks. The decline is steepest in high-income countries that once posted daily case counts in the hundreds of thousands. The United Kingdom wound down its free universal testing program in April 2022, and the United States ended its federal reimbursement programme for uninsured individuals the following year. Similar rollbacks have occurred across continental Europe, Canada, and parts of East Asia.

The contraction is partly financial. Many ministries of health treat SARS-CoV-2 testing as a line item to be trimmed rather than a permanent public health function. Manufacturers of PCR reagents have scaled back production, and several companies that flourished during the surge have either merged or exited the market. Smaller laboratories in low- and middle-income countries that relied on donated equipment now report stockouts of consumables, with shipping costs for some extraction kits having tripled since 2021.

Surveillance systems built on sentinel testing in hospitals, aged care facilities, and primary care clinics are also weakening. When clinicians stop swabbing routinely because guidance no longer requires it, the data stream that public health agencies depend on grows shallow. Epidemiologists compare the current landscape to flying through fog with instruments turned off: a sudden change in conditions could catch the entire system off guard.

Where the surveillance gaps are widening

Africa remains the most under-represented continent in genomic databases. Despite hosting roughly 17 percent of the world's population, the region contributes less than 1 percent of the SARS-CoV-2 sequences deposited in global repositories. South Africa, with its well-regarded Network for Genomic Surveillance, is a notable exception, but neighbouring countries struggle to maintain even basic testing throughput. A similar pattern holds in parts of Central America, the Pacific Islands, and the mountainous regions of South Asia.

Even wealthy nations show blind spots. Rural counties in the United States, regional areas of Spain and Italy, and remote districts in Japan have reported weeks-long stretches without a single positive sample being sequenced. The result is a mosaic map of variant prevalence that is denser in capital cities and thinner in the countryside. When a new lineage emerges, the first sign is often a cluster of hospitalisations rather than a sequenced genome, which means the warning arrives days or weeks later than it should.

Aid organisations have flagged the uneven picture repeatedly. The World Health Organization's laboratory network still ships reagents to dozens of countries, but demand now exceeds supply in the most fragile settings. In a recent briefing, the agency noted that only 27 of 194 member states were submitting sequencing data at the frequency and depth needed to detect emerging variants in real time.

Why sequencing depends on sampling

Genomic surveillance does not operate in a vacuum. Every sequenced specimen begins as a positive test somewhere in the world. When testing drops, the pool of candidates for sequencing shrinks proportionally. Laboratories typically select a random fraction of positives for whole-genome analysis, often weighted toward high-viral-load samples, travellers, and people with severe disease. If a country goes from 50,000 daily tests to 5,000, the absolute number of genomes it can produce falls by the same factor even if its sequencing throughput remains constant.

This is why the current wave of testing cuts is so consequential. The lineages that have caused the most concern in recent months, including the JN.1 family and its growing constellation of descendants, were first identified in countries with robust sampling. Had they emerged in a region with negligible testing, they might have circulated for months before being detected, and by then the window for containing them would have closed.

The mathematical relationship between testing and variant detection is not subtle. Modellers working with the GISAID database estimate that for every tenfold reduction in test volume, the lag in identifying a new variant extends by roughly 18 to 25 days. In practical terms, a country testing 1 percent of its suspected cases will learn about a new lineage only when it has already become dominant.

Australia's testing landscape in flux

Australia entered the pandemic with one of the most aggressive testing regimes in the world, particularly during the long lockdowns of 2021 and 2022. Melbourne and Sydney residents queued for hours at drive-through clinics, and rapid antigen tests became a scarce commodity in Brisbane pharmacies when supply chains snapped in early 2022. That era shaped public expectations, and many Australians still reach for a rapid test at the first sign of a sore throat.

The national regime has loosened considerably since then. The Australian Health Protection Principal Committee no longer recommends routine asymptomatic testing, and most states have wound down their dedicated respiratory clinics. The Therapeutic Goods Administration continues to approve new rapid antigen test brands, and the products remain widely available at Chemist Warehouse, Priceline, and major supermarkets, with prices generally ranging from A$5 to A$15 per pack of two.

Federal biosecurity measures, last extended in early 2024, still grant the government powers to mandate testing at international borders, and Queensland's wastewater surveillance program continues to monitor sewage in more than 60 catchments. Researchers at the University of Sydney and the Doherty Institute have warned, however, that the contraction of clinical testing is leaving local sequencing efforts underfed. A single Adelaide laboratory reportedly receives fewer than 100 suitable samples per week, down from several thousand at the height of the Omicron wave.

The economic dimension also matters. Australian manufacturers of PCR reagents have largely pivoted to other products, and importing fresh consumables from Europe now takes longer than it did in 2021. Some pathology providers have begun charging gap fees for COVID-19 tests that were once bulk-billed, and bulk-billed PCR testing is now difficult to access outside of hospital settings and a handful of bulk-billing general practices in Perth and Darwin.

Comparing testing strategies worldwide

The summary below compares the testing approach in selected countries, showing how each balances accessibility, sequencing integration, and the level of public funding committed in 2024.

The pattern shows that countries which preserved at least some form of free symptomatic testing, Germany and Japan among them, continue to feed their genomic surveillance systems with high-quality data. The United Kingdom, despite its world-class sequencing infrastructure at the Wellcome Sanger Institute, now generates far fewer usable samples per week than its laboratory capacity could process.

Wastewater and digital detection step in

In the absence of clinical testing, several complementary surveillance methods have gained ground. Wastewater monitoring, which gained mainstream attention during the 2021 outbreaks in Melbourne's western suburbs, has matured into a reliable early-warning system in many cities. By sequencing viral fragments in sewage, researchers can estimate community prevalence and sometimes identify new lineages before they appear in clinical samples.

Open-data initiatives allow individuals to log positive test results anonymously, providing a rough proxy for case counts when official figures are no longer published. Aggregated dashboards such as coronavirusnewslive.com pull together statistics, policy changes, and laboratory reports into a single feed that updates throughout the day. Australia has invested modestly in this area, with state health departments in New South Wales and Victoria publishing weekly wastewater trend reports that are accessible to the public.

Airport genomic surveillance, once a niche project, has also matured. Countries including Singapore, the United Arab Emirates, and the United States now routinely sample wastewater from arriving aircraft, providing a direct window into the variants entering their borders. Australian researchers at the Kirby Institute have called for a similar national scheme, arguing that targeted genomic sampling at points of entry offers high value at relatively low cost compared with universal community testing.

Practical steps to strengthen detection

Public health authorities, clinicians, and individuals can each take steps to keep variant surveillance from collapsing further. The following recommendations are drawn from recent guidance issued by the World Health Organization, the European Centre for Disease Prevention and Control, and several national academies of science.

• Restore access to free or low-cost PCR testing for symptomatic individuals in regional and rural areas, where sequencing yields are currently lowest.
• Maintain and expand wastewater surveillance programs in major cities and tourist destinations, including coastal Queensland and the Gold Coast hinterland.
• Integrate rapid antigen test results into a single national reporting platform, allowing public health teams to estimate prevalence without relying on laboratory confirmation alone.
• Fund sentinel genomic surveillance in hospitals, with priority given to intensive care units and aged care facilities where severe cases cluster.
• Strengthen regional laboratory networks across Southeast Asia and the Pacific, ensuring that samples from low-income neighbours can reach sequencing hubs within days rather than weeks.
• Continue to publish weekly variant prevalence reports in plain language so that clinicians, journalists, and the public can track changes in real time.
• Reserve the option to rapidly scale testing back up under national biosecurity legislation, ensuring that contracts, reagents, and trained staff remain on standby.

Readers who want to follow emerging laboratory and policy developments across regions can find additional analysis on global health resources. The coming winter season in the southern hemisphere will test whether the thinned diagnostic net can still catch the next lineage before it spreads widely, and the next few months are likely to determine how much early warning the world retains going into 2025.