Covid-19 is here to stay. However, with careful management, we can prevent future outbreaks and move from pandemic to endemic. But what does that mean and what should we do to stop it from erupting again?
Even with successful vaccination programs, we cannot expect to completely eradicate Covid-19 from the world.
It will continue to circulate for many years to come.
Right now, Covid-19 is spread almost all over the globe. Over time, in most countries, it will change from an epidemic disease – when the number of cases suddenly increases – to an endemic disease – when cases continue to appear over a long period of time, with periodic peaks and troughs.
Many diseases are endemic, ranging from relatively minor ones like the common cold viruses to serious killers like malaria.
A disease can become endemic in a small region, like Lassa fever in parts of West Africa, or worldwide, like chickenpox.
An infectious disease becomes endemic when it is not spreading so fast that it gets out of control, but at the same time it is not completely eliminated. This may be because:
- we develop only limited immunity;
- the disease spreads in ways that we cannot completely prevent – for example, through insect bites, when we breathe or talk, or;
- the disease is spread in wildlife populations where it cannot be eradicated.
In fact, the only human infectious disease that we have been able to completely eradicate is smallpox. It was a long and complex process and required a global effort, aided by the facts that smallpox infects only humans (not animals), it has a short incubation period, and we had a highly effective smallpox vaccine.
For most other diseases, complete elimination is not possible – we reduce their spread through measures such as vaccination.
Outlook for post-pandemic Covid-19
This is something that is starting to happen with Covid-19 in countries that have had access to vaccines, such as the UK, Germany and the US.
People are increasingly building up immunity through a combination of vaccinations, booster doses and the natural immunity that people develop after infection. However, where there was no vaccine, the level of protection against the virus is lower.
The longer the virus continues to spread among largely unvaccinated populations, the more likely it is to evolve and create new variants, such as Omicron or Delta. These could spread faster or cause more serious illness in humans and even reduce the effectiveness of our current vaccines.
If we can increase global immunity, it will make it harder for the coronavirus to spread.
We could then get to a point where countries regularly have only a small number of Covid-19 cases – which might seem like mission accomplished. But we still have work to do to protect ourselves.
An example of large outbreaks that started again after the disease was brought under control is measles in 2018. Vaccination rates dropped in several countries, causing collective immunity to fall below the threshold that kept the disease under control, and the number of cases worldwide rose to around 10 million.
So, what can we do to fight Covid-19 in the future?
This pandemic is not yet under control, and there is still much we do not know about Covid-19, including how long a person’s current immunity can last and the impact of existing and future variants.
But we already know what a long-term plan to deal with Covid-19 should include:
- Monitoring the virus. Knowledge is power, and the global genomic surveillance program, combined with other epidemiological and clinical data, will tell us when and where the virus is spreading and how it is evolving. Let’s not be caught off guard again.
- Invest in vaccines and treatments. If new variants emerge, such as Omicron or Delta, that behave more dangerously, we must be prepared to find ways to prevent their spread, treat people who become infected, and reduce the overall impact on health systems and societies.
- Ensure everyone in the world has access to vaccines, treatment and tests. If we have learned anything over the past two years, it is that infection anywhere is a threat everywhere. The more people who have Covid-19, the more chances the virus has to grow and spread. This means that controlling the virus in any country will benefit people in all other countries.
- Sharing and coordinating resources. Many countries do not have the means to implement effective vaccination programs. For reasons of solidarity and self-interest, richer countries need to invest in the ACT-Accelerator, a global collaboration to ensure access to tests, treatment and vaccines for everyone, everywhere. Wealthy countries that have provided many excess doses of vaccine can also donate them through COVAX, ensuring that vaccines get to where they are needed most.
- Global solidarity. Acting in national self-interest will only perpetuate this crisis, trapping us in a cycle of waves, new options, lost lives, and continued economic and social disruption. Clear and rational political decision-making, communication and global cooperation are crucial if we are to end the pandemic.