THERE are rising numbers of COVID-19 cases in many parts of the world, and the World Health Organization (WHO) says there are a number of reasons this is happening.

Speaking during the WHO’s Science in 5 programme, Dr Maria Van Kerkhove, technical lead for COVID-19 at the WHO Health Emergencies Programme, said the first reason is the virus continues to evolve.

“Since Omicron [variant] first emerged we’ve had more than 900 sub -ineages of Omicron in circulation, and we’re tracking each and every one of those, and we’ll come to those in a moment. The other reason is that we have a lifting of public health and social measures so people are living their lives, and they’re living their lives as safely as possible because we have increasing vaccination coverage around the world and we have increasing levels of immunity from vaccination and/or past infection,” she explained.

But Van Kerkhove warned that immunity does wane over time, which means people can become infected.

“And the combination of variants that emerge that have increased transmissibility — which means they can infect people more easily because there are properties of immune escape — means that people can be reinfected again so this is something we will have to deal with going forward. Right now we are seeing an increase in case reporting from a number of countries around the world.

“For example, one of these countries is India. And one of the reasons why we are seeing an increase in case detection is likely because of the sub-lineage XBB.1.16. XBB.1.16 does have increased transmissibility, but we have not yet seen a change in severity.”

She said another reason we’re likely seeing an increase in case reporting from India is because one of the last big waves of infection that India experienced was the Delta wave.

“And that was quite some time ago. While we are seeing an increase in case reporting in a number of countries around the world, we are not really seeing an increase in hospitalisations and deaths. It’s not true in all countries. We still see hospitalisations, and at the present time we estimate that hundreds of thousands of people are in hospital each week due to COVID-19,” Van Kerkhove said.

But because we have access to diagnostics, she added, “early clinical care, and the use of antivirals and safe and effective vaccines, people who are infected or reinfected with SARS-CoV-2 are not dying as frequently as they were in the beginning of this pandemic when we didn’t have treatments and we didn’t have vaccines”.

Van Kerkhove said governments need to ensure there is access to rapid diagnostics, that people are tested very quickly so they can get into the “clinical care pathway”, and that people have access to antivirals so they can be treated very quickly so as not to develop severe disease.

“We have to work on increasing primary vaccination coverage, particularly in low- and middle-income countries. And we have to ensure those who are most at risk for severe disease receive the boosters according to need.”