Don’t panic about rising Covid cases. Hospitalisation & deaths are the real metric: Experts

Late last month, India detected its first cases of Covid caused by the BA.4 and BA.5 sub-lineages of the Omicron variant, and the country on Friday reported a nearly three-month high of over 4,000 new infections. The Omicron sub-variants drove a surge in South Africa in May though a preprint of a new study shows that over 87% of the population was previously infected. However, with a slower rate of increase in cases, less hospitalisation, fewer deaths, South Africa is moving to a different way of living with Covid, where there is less panic about case numbers. But boosters are critical, since we do not know when immunity wanes, say Dr Michelle Groome, head, division of public health surveillance and response, National Institute for Communicable Diseases, South Africa, and Professor Sheetal Silal, director, Modelling and Simulation Hub, Africa, University of Cape Town, in an interview with Indulekha Aravind on a Zoom call. Edited excerpts:

How does the latest surge in cases driven by BA.4 and BA.5 compare with previous waves?

Michelle Groome (MG): We started seeing small increases in the number of cases where we identified the BA.4 and BA.5 sub lineages. But the rate of increase was not as quick as what we had seen with the initial Omicron wave with BA.1 in December. And we saw very low numbers of hospitalisation compared even with what we had seen with the initial BA.1 wave and very small number of deaths. And the resurgence seems to have settled. Also, there are other differences. For example, our testing rates overall are much lower currently, so direct wave-to-wave comparisons are difficult.

Sheetal Silal (SS): In South Africa, we have moved away from this terminology of a wave. We need to be careful about the language that we use. Different metrics are appropriate at different stages of the pandemic. For example, a wave of cases has previously been a precursor to a wave of severe Covid-19 hospitalisation and deaths. But now we have to consider the levels of previous infection and vaccination in the population. In South Africa, with high levels of previous infection (and similarly, in India, with high levels of both previous infection and vaccination), a large number of cases may not necessarily result in a large number of hospitalisation. So if we continue to highlight only the increase in cases, we run the risk of causing unnecessary public panic. The thinking around the pandemic and how we characterise and measure it needs to change. Now we should be concerned about monitoring metrics to assess when future resurgences become an acute public health burden.

How important are booster doses — an area where India is lagging?

Michelle Groome : I think we have very similar issues to India — our booster uptake hasn’t been great. Part of it is because people have the feel- ing that if they have had Covid, they are protected and why must they have a vaccine. There has also been quite a lot of misinformation. We need to get the message out there that we don’t know much about waning immunity and so we don’t know how long this protection will last. Definitely, for those at higher risk, booster will give you longer protection against severe disease.

Sheetal Silal (SS): With high seroprevalence and some vaccine uptake already, we do run that risk of the narrative that okay, well, we’ve got some protection already. Maybe now more than ever before, the targeting of the vaccines, of the boosters, becomes important.

Based on your experience of dealing with sub lineages, what are the one or two things that policymakers should keep in mind?

Sheetal Silal: The role of the media here is very important. If the media were to be putting out information on the slow increase in hospitalisation and deaths despite the increase in cases, it would start to change the narrative and send a different message out to what we have just become accustomed to over the last two years.

Michelle Groome : The main thing is not to panic about increasing case numbers. We need to be focusing on measuring, you know, hospitalisation and deaths as the real metric going forward.

How important is wastewater surveillance in detecting a prospective surge?

Michelle Groome : One thing we are also trying to get across is a move away from lockdowns and public health response and moving more to individual, riskbased response. So you do away with mandated mask-wearing but if you are an elderly person with an underlying disease, you would then choose to wear a mask or maybe choose not to go to a big public gathering. So, something like wastewater surveillance, where you are detecting the virus in wastewater, may just be able to give an indication of where there may be higher case numbers. People can go to the dashboard of their district and if there was an increase of SARS-CoV-2 in their province or district, those at high risk might want to take additional precautions. As we change our thinking towards Covid, I think more and more sentinel surveillance is going to be important as a mechanism to be able to track what’s happening with this and other viruses.

Sheetal Silal:Setting up systems relevant to other diseases and not just Covid but which have a far greater benefit to society, such as wastewater surveillance, becomes even more important. It is hard to justify such spend perhaps in a nonpandemic setting so this is almost opportune, if there is interest in setting up these kinds of infrastructure.

What should individuals do in terms of precautions?

Michelle Groome : For the most part, people are tired of Covid and any type of restriction. We should highlight those at higher risk, for example the elderly and those with comorbidities, and tell them these are the ways you could limit exposure to respiratory viruses in general. The other thing is, with the Omicron wave and even now, we had very few restrictions in place (in South Africa). So you are seeing low number of hospitalisation, with life practically back to normal. It’s encouraging that we are not seeing a surge in hospitalisation and deaths in the face of that.

Sheetal Silal:I think it’s important to learn from the East Asian example. After SARS and H1N1, it’s become normal practice to wear a mask, if you’re symptomatic. The government can participate in social communication and what constitutes responsible behaviour and hygiene practices without necessarily mandating them. If we were to change the approach and promote good hygiene, that’s a very big win not just for Covid but for all respiratory diseases.

(With inputs from health)