The World Health Organization may no longer consider Covid-19 a global health emergency, but the virus is not going anywhere.

While the UN agency's lifting of its highest alert level on Friday marks a turning point in the pandemic, the virus is still circulating around the world and could still surprise us, experts warn.

Here is the current state of play for Covid, which WHO chief Tedros Adhanom Ghebreyesus said has now killed at least 20 million people.

- Occasional surges -

After the massive waves of infections that hit countries in the pandemic's early stages, the number of deaths from Covid has dramatically fallen, largely due to increased immunity from vaccination or previous infection.

Covid deaths have dropped by 95 percent since the start of the year, according to the WHO.

Experts now expect a lower normal level of Covid to be punctuated with seasonal resurgences, similar to influenza.

WHO chief Tedros Adhanom Ghebreyesus on Thursday warned against "pandemic fatigue".

"This virus is here to stay, and all countries will need to learn to manage it alongside other infectious diseases," he said.

- Toll -

More than 765 million Covid infections and nearly seven million deaths have been officially reported to the WHO since the start of the pandemic.

However Tedros said on Friday that at least 20 million people were estimated to have been killed by Covid -- nearly three times the official number.

To make up for inconsistently collected or incomplete national tolls, researchers have compared the number of excess deaths worldwide since 2020 to the pre-pandemic figures.

For 2020 and 2021, nearly 15 million excess deaths were due to Covid, either from the disease itself or indirectly through its impact on society, the WHO has said previously.

Last week Patrick Gerland, chief of the UN's population estimates section, told AFP that they were still waiting on data about 2022 excess deaths from India, which may have been the country with the highest toll.

- Variants -

Since the Omicron variant emerged in late 2021, a range of its subvariants have been competing for dominance.

Most recently, the Omicron subvariant XBB.1.16 has been rising in several countries.

WHO chief Tedros Adhanom Ghebreyesus has said that XBB.1.16's emergence "illustrates the virus is still changing, and is still capable of causing new waves of disease and death".

While XBB.1.16 is not thought to be significantly more dangerous than previous strains, experts warn that the virus could yet mutate into deadlier or more transmissible variants.

The WHO has emphasised the importance that countries continue monitoring variants in real time.

- Vaccines and treatments -

Vaccines were developed against Covid in record time and have proved a powerful weapon against the virus, with more than 13 billion doses administered worldwide so far.

However vaccination rates have varied widely between rich and poor countries, sparking calls to address the gap in access.

Pharmaceutical companies have meanwhile updated their vaccines hoping to target new variants, while booster doses have been recommended for vulnerable people.

New ways to administer the vaccines, such as through the nose or skin, are also under various stages of development.

Mutating Omicron strains have reduced the number of effective treatments against Covid -- only a couple of antiviral drugs and a monoclonal antibody are now recommended for people who are seriously ill.

- Long Covid -

One of the most significant legacies of the pandemic may be Long Covid, a condition estimated to occur after 10 percent of coronavirus infections, according to the WHO.

Common symptoms include fatigue, breathlessness and a lack of mental clarity called brain fog that continue at least three months after the initial infection.

However much about the condition remains unknown, including why it effects some people more than others, making it difficult to diagnose or treat.

- Next pandemic? -

Even before Covid was no longer classified as an emergency, attention had turned towards the next pandemic.

The Red Cross warned earlier this year that the world remained "dangerously unprepared" for a future health crisis.

Efforts have been launched to monitor potentially dangerous viruses in the hopes of identifying and countering a possible "disease X" behind a potential outbreak.

Three quarters of the new pathogens detected in humans over the last 30 years crossed over from animals.

These zoonotic diseases are becoming more common due to climate change, experts have warned.