with him Surge in COVID-19 cases in Chinaafter Easing its draconian zero-covid policy In December, there are fears that the pandemic may be entering a new, uncertain phase. in conversation moderated by Zubeida Hamid, Soumya Swaminathan And giridhar r babu Discuss the situation in China and the possible impact in India. Edited excerpts:
Why ,
China is witnessing an explosion in Covid-19 cases after easing its zero-Covid policy. What is happening? Can it affect India?
a , Soumya Swaminathan: We have now completed three years, we are in the fourth year of the pandemic. One thing has become clear that this virus is not going to end soon. We have also seen that this virus has a remarkable ability to evolve. now, especially in China because they had such a strict zero-covid policy Over the years, there has been very little natural infection, and the only protection people have is vaccination. Unfortunately, in China, vaccination rates for those over 60 are less than ideal. As we know, if you are an older person, you have underlying co-morbidities, chronic diseases, and the risk of becoming critically ill is very high. That’s why there is a concern today that not only in China, there may be omicron subtype causes a massive increase in infections, but this can potentially translate into a significant amount of both morbidity and mortality.
A ,
India is in a different position because we have high vaccination coverage, which includes the elderly. What we don’t have is a lot of booster uptake. But there has been a lot of natural infection in the last three years, and so people have built up a good level of protective immunity at the population level. This should be good enough to prevent an increase in hospitalizations or mortality.
a , Giridhar R Babu: From an epidemiological perspective, any wave or outbreak can result from three important things: how the agent (here, the virus) is changing, how humans are immune, and finally how the environment is facilitating this transmission. Of the three factors, there is an advantage for India and other countries where host immunity is superior, whether due to hybrid immunity or relatively expanded vaccine coverage. But we must remember that this is not a static concept. It’s a dynamic concept, meaning that immunity in the host keeps changing as you have the virus evolving; Whether the antibodies are long lasting, or whether the immunological memory is strong enough to prevent further attacks from new incarnations of the virus, are questions we need to investigate. So far we have the advantage in terms of hybrid immunity. The weak point is in terms of low booster coverage, which must be increased, especially for the elderly, where 50% have not received it, and for all adults. Although booster doses are important, millions of young adults are being added to the population each day. So we should also make sure that they get vaccinated. Without it, dynamic equilibrium would be lost.
Why ,
India has so far given more than 220 crore doses of the vaccine. Since we know that the coronavirus keeps mutating, with new forms of anxiety, what does the scientific evidence tell us about getting asymptomatic booster shots?
A , Soumya Swaminathan: This is an important question. We need to base our public health advice on data. The first is your own age, health status, etc. Secondly is the time after vaccination or infection, we know that immunity wanes. The third is a virus and we know that it has been so transmissible since Omicron emerged that even high levels of neutralizing antibodies were not able to stop the infection completely. So the third dose, this is really to stimulate the immune response, remind the immune system about the antigen and prepare the immune system to face any infection that it may see.
A , How many boosters do we need? How often do we need these boosters? Is this going to be an annual event in the future? These are still open-ended questions. Again, we need good data as the population profile varies from country to country. The vaccines that were used are different. From the studies done so far, the data points to an advantage of a heterologous boost, meaning that if you’ve had the first two shots with an adenoviral-vector vaccine, and you get a third shot with a protein subunit or mRNA vaccine, Or conversely, perhaps what it does is it helps stimulate various parts of the immune system. Still limited data. But regardless of which one is used, I think the third dose is important for all age groups; 4th dose probably only for high risk people.
a , Giridhar R Babu: A third dose has shown almost worldwide evidence of effectiveness against newer version, including Omicron. Which means that even though the vaccines are not specific to Omicron, the booster doses helped mount an immune response against the new lineages. Having said that, the evidence for fourth dose or consecutive doses or even annual vaccination schedule for COVID-19 is not yet there. This is where most of the confusion lies, as there are countries that have done four and are preparing for the fifth, and there are countries that do not have enough vaccines to complete the primary immunization programme. When you have such disparity on a global scale, each country should have its own evidence base.
Why ,
The Union Health Ministry has said that states should resume genome sequencing of new COVID-19 cases. How well are we doing in this regard in India? Does it need to be extended in the light of the emergence of new forms?
a , Soumya Swaminathan: Genomic sequencing and surveillance have played a very important role in this pandemic. In fact, if you look at GISAID, which is the database hosting the whole genome sequences of the SARS-CoV-2 virus, there are about 14 million whole genome sequences; About half of them are from the Omicron strain alone. When we think about genomic surveillance, it’s important to be very strategic about it. Good representation is needed in individual states, because sometimes you can have blind spots. If you looked at data from India – for example, INSACOG (Indian SARS-CoV-2 Genomics Consortium) – I think more than 25% of the samples come from Maharashtra alone. If you have very limited samples coming in from other states, you can really miss what’s happening. We need to be clear about what we are indexing. All of this requires real-time data collection, but also analysis, reporting and public health action. Otherwise, it is of no use as an academic exercise. I think where we are able to use the data that is coming out to take public health action, maybe we can do a little bit better.
A , Giridhar R Babu: INSACOG is a consortium of laboratories, and as a consortium, they are doing really well with their stated purpose. But we have to take a step back. For example, not all laboratories are now linked to the IHIP (Integrated Health Information Platform); This means that there are many other hospitals and laboratories that need to be connected to the platform. So what we need to do is integrate surveillance mechanisms at the peripheral level, expand the infrastructure, have consortiums, not only of laboratories but also of hospitals, and link this with public health operations.
Why ,
Would you say that there is really no real concern regarding another wave in India, but we still need to keep masking up and take other COVID-19 precautions this year as well?
a , Giridhar R Babu: Whether there is real concern from the current lineage in China or elsewhere, it does not appear so for hospitalizations and deaths, but there will be greater risk if a new variant develops. So we need to follow the signs in terms of understanding where new clusters are developing. What are the symptoms? What is its genomic sequencing? And then what is the level of population immunity there? and from there, take the next step in terms of whether we should be stricter [rules] Or not. At present, panic is high in most countries, systematic reinforcement is low, and panic should not lead to epidemic control.
Dr. Soumya Swaminathan is the former Chief Scientist of the World Health Organization; Dr. Giridhar R. Babu is professor and head of Life Course Epidemiology at the Indian Institute of Public Health, PHFI, Bengaluru