A thrill of hope for an end to COVID: From epidemic, to pandemic, to endemic, where are we now?

Most scientists agree: SARS-CoV-2, the virus behind the current pandemic, will eventually “burn out”. Meaning: it could pose less danger to health over time, like the Spanish Flu itself, i.e. less deadly, though it may at times burden the healthcare system, and still cause deaths.

A recent Nature poll shows 89% of scientists (111 immunologists in 23 countries) believe that SARS-CoV-2 will “very likely” or “likely” become an endemic virus.

How will the pandemic pan out?

Experts point to some basics, starting with what they call “disease burden”.

Dr Monica Gandhi, Professor of Medicine, University of California, San Francisco (UCSF), said: “An ‘epidemic’ means you have an undue burden of disease, more than expected…a lot of hospitals being flooded, people being really sick. A ‘pandemic’ means it’s extended to multiple continents. ‘Endemic’ means it’s gone down to a level where you live with it. And it’s at such a level that is doesn’t cause an undue burden.”

Who gets to define what “undue burden” means? “Everyone has to decide what ‘undue burden’ means for themselves as a country — (in terms) of hospitalisations or disease,” added Dr Gandhi.

Can we eradicate COVID-19?

“But I’m sorry to say this: we’re not gonna eradicate COVID, because of some very key pathogenic properties about it — it’s very transmissible, it’s like another bunch of respiratory viruses,” she added.

However, “in places where there are low hospitalisations and deaths, you can argue that it (endemicity) has been reached,” she said. On Sunday (November 7, 2021), 450,299 new cases of COVID-19 were reported worldwide (based on seven-day average), down about 45% from the peak of 823,545 recorded on April 27, 2021.

Deaths, meanwhile, have dropped more than 55% from the January 27, 2021 peak of 15,703 seven-day average to 6,983 on November 7, according to Our World in Data.

Many scientists say that a big factor in the COVID "endemicity" equation is how robust the vaccines perform in the face of fast-mutating variants. If efficacy does not wane significantly and most people vaccinate, the disease burden will stay low.

Professor Trevor Bedford, a computational virologist at at the Fred Hutchinson Cancer Research Centre in Seattle, stated in a Twitter thread: "At endemicity, circulation does not necessarily translate to disease burden. Based on robust vaccine effectiveness against severe outcomes, my speculative guess would be that infection to fatality rate (IFR) drops 10-fold from its original ~0.6% to a flu-like ~0.06%."

What does an endemic COVID look like?

Epidemiologists say the disease burden from endemic COVID may look like a cross between that of the flu and the other common coronaviruses. Bedford has calculated that the Delta variants of SARS-CoV-2 reproduces twice as fast as H3N2, one of the most common flu strains.

Are we there — endemic COVID — already?

No. WHO epidemiologist Dr. Maria Van Kerkhove, also the agency’s COVID-19 technical lead, said the pandemic is still very much on, especially in places where vaccination rates are low, or where there’s high vaccine hesitancy, or both.

Van Kerhoove also stressed on the need for clear messaging. “We’re not in a state right now where it’s endemic. Endemic does not mean that this virus is not dangerous. Endemic does not mean that we give up. That’s the narrative that I’m seeing in the public.”

More importantly, however, she urged a renewed commitment to vaccine “equity”, i.e. making more vaccines available to poor countries. A lasting economic development, she stressed, can only happen with health for all.

Why are transmissions soaring in certain places?

COVID transmissions rates and deaths are still soaring in places where vaccination drive is poor, or where vaccine hesitancy is high. It is now a leading cause of deaths among unvaccinated people in the US, Europe as well as Russia. More than 90% of those hospitalised with COVID are among the unvaccinated in these countries. As for deaths, up to 99% are among the unvaccinated. Germany, for example, is facing a massive pandemic surge among the unvaccinated.

From January to June 2021, COVID accounted for just 1% of deaths among fully vaccinated people in the UK, NHS data show. Among the unvaccinated, the disease caused 37% of deaths, and nearly 100% of COVID-19 deaths in the UK now are among the unvaccinated. An average of 2,000 people still die of COVID-19 every day in Europe, with 1 million infections reported in the continent each week, according to the European CDC.

Vaccine hesitancy, anti-science and protests against the so-called vaccine passport has taken a new form in the bloc. Incidents, some violent, against medical professionals, media and the general public have been reported in countries including Italy, the Netherlands, the UK, Poland, Slovenia and France.

DAILY DEATHS FROM COVID: (7 day average, as of October 18, 2021)

(Source: Johns Hopkins University CSSE)

What's the long-term view?

Epidemiologist Dr David Heymann, of the London School of Hygiene and Tropical Medicine, who for 22 years was based at the WHO in Geneva on secondment from CDC, said the disease appears to be becoming endemic and will therefore likely remain a risk to all countries for the foreseeable future. “All countries are at risk,” said Dr Heymann said.

“Clearly, no one will be able to understand what the long-term impact has been until that long term, those next five years or so, have passed,” told interview during a conference organised by European Society of Clinical Microbiology and Infectious Disease conference."

In the short term, however, studies show that approved COVID vaccines have not required updates so far, though studies reported new strains have reduced vaccine efficacy.

Meanwhile, drug regulators have authorised the 'mix and match' of vaccine boosters, for example, by using a single dose of Pfizer, Moderna, or Johnson & Johnson shot to be used for third dose, a move authorised by the US FDA on Thursday (October 21, 2021).

What is the role of vaccines towards ‘endimicity’?

Vaccines, which now cover about one-third of humanity, offer a “shortcut” to endemicity, say experts. Nature reports that much depends on two key factors: the virus' ability to mutate and the efficacy of vaccines in the long term.

If immunity wanes, the shots may have to be tweaked or "reformulated" to target not only the wild type but also the newer, more transmissible and virulent variants.

Despite the loud anti-vax voices on social media, and even on the streets in certain cities of the world, the data show vaccines have saved hundreds of thousands of lives. People who are COVID-fatigued and just about managing to survive under the collective stresses vent their frustration on a perceived inconvenience (vaccine passport). However, COVID is a truly unprecedented global pandemic that requires necessary mutual protection, which may take away some individual preferences in favour of collective action, and other may find extra-difficult.

Still, there's an incontrovertible fact: vaccines show a way out of the pandemic, as they allow healthcare systems to keep running, by preventing them from getting overwhelmed with severely ill patients.

Most experts agree that the key to bringing the threat down, is to bridge the “vaccine gap” — by ramping vaccination rates up, especially in poor countries. This requires bold decisions at a global level. On Tuesday, the WHO highlighted the need to protect healthcare workers and seniors in the poorest contries.

What percentage of the world has immunity today?

Numerous vaccine data sets are now available as nearly 2.8 billion people are already fully vaccinated. As of October 19, 2021, some 6.72 billion doses had already been administered, Our World in Data shows. Given these figures, there’s no debate that that it would have been far deadlier otherwise.

If the number of those who recovered is included, some experts estimate that more than half the world’s population already has some degree of immunity to COVID.

In a scenario where most people had been immunised, COVID may still severely sicken the old and infirm, like the flu sometimes does, but life goes on outside the hospital — as the fear factor wears off, and perhaps a new glorious morn of normalcy will return.