Scientist warns that Covid will never become an endemic virus.

• The WHO cautioned that the next Covid variant may be even more contagious than omicron last week.
• An epidemic is defined as a sudden increase in the number of cases of a disease beyond what is typically expected, as stated by the U.S. Centers for Disease Control and Prevention.
• When a disease's growth is exponential and it is spreading globally, the WHO declares it a pandemic.

An expert in biosecurity has warned that Covid-19 will always behave like an epidemic virus and will never become an endemic illness.

Professor Raina MacIntyre of the University of New South Wales in Sydney stated to CNBC that while endemic diseases can affect a vast number of people, the number of cases does not fluctuate rapidly as observed with the coronavirus.

If case numbers change with an endemic disease, it is typically over years, whereas epidemic diseases rise rapidly over periods of days to weeks.

Experts at Imperial College London estimate that the R0 for omicron could be higher than 3, indicating how quickly the disease is spreading. Scientists use the R naught (or R0) equation to assess the rate of disease spread.

An epidemic is likely to occur if the R0 of a disease is greater than 1, as this indicates exponential growth and the spread of the virus, according to MacIntyre.

The objective of public health is to maintain the effective R, which is R0 adjusted by interventions such as vaccines, masks, or other mitigations, below 1. However, if the R0 is greater than 1, we usually observe recurrent epidemic waves for respiratory transmitted epidemic infections.

MacIntyre observed that the pattern of seeing major waves with smallpox, measles, influenza, and now Covid-19 has been consistent for centuries.

Covid will not become a malaria-like endemic infection with constant infection levels, but rather will continue to cause epidemic waves due to waning vaccine immunity, new variants that evade vaccine protection, unvaccinated populations, births, and migration.

To prevent major disruptions to society, we must implement a continuous "vaccine-plus" and ventilation strategy, as advised by MacIntyre, who also cautioned that new variants are on the horizon.

The World Health Organization cautioned that the next Covid variant may be even more contagious than omicron, posing a greater threat.

Last year, Global Biosecurity, a collective of UNSW research departments covering epidemics, pandemics, and epidemiology, predicted that Covid will exhibit the cyclical pattern of epidemic diseases.

The organization stated that Covid will never become endemic as it is an epidemic disease that will always exist. It will continue to spread rapidly among unvaccinated or under-vaccinated individuals.

Pandemic, epidemic or endemic?

An epidemic is defined as a sudden increase in the number of cases of a disease beyond what is typically expected, as stated by the U.S. Centers for Disease Control and Prevention.

When a disease's growth is exponential and it is spreading globally, the WHO declares it a pandemic.

According to experts from Columbia University's Mailman School of Public Health, the difference between an epidemic and a pandemic lies not in the severity of the disease, but in the extent of its spread. While an epidemic is typically contained or anticipated, a pandemic is global and uncontrollable.

The Centers for Disease Control and Prevention (CDC) define endemic disease as the consistent occurrence or typical incidence of a disease or infectious agent within a population in a specific geographic region.

The American Lung Association emphasizes that for Covid to become endemic, a sufficient number of individuals must have immunity to it, which highlights the significance of vaccination in the transition of the virus from pandemic to endemic status.

If the right course of action, including addressing vaccine and health-care inequity, is taken, there is a possibility that Covid could be ended as a global health emergency this year, said Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization (WHO) last week.

A week after a senior WHO official stated that "we won't ever end the virus" and that "endemic does not mean 'good,' it just means 'here forever,'" his comments were made.