Coronavirus | Data is key to control of this pandemic, says Soumya Swaminathan
Lockdowns alone can’t be effective unless combined with other health measures, says the WHO Chief Scientist.
Dr. Soumya Swaminathan, Chief Scientist at the World Health Organisation, tells The Hindu in an interview that the fight against COVID-19 is likely to be long-term, and lockdowns alone cannot be effective unless combined with other public health measures. Dr. Swaminathan, who has worked in research on tuberculosis and HIV for 30 years, was previously Secretary to the Government of India for Health Research and Director General of the Indian Council of Medical Research (ICMR) from 2015 to 2017. Edited excerpts:
What do we know so far about how SARS-CoV-2 is spreading around the world? Is there evidence to suggest a variance in its virulence in different countries?
Viral evolution and transmission dynamics can be studied by analysing genetic sequence data. We first got the viral sequences from China through the GISAID platform, which was set up 10 years ago for influenza sequence sharing, and since then, many countries have provided sequence data as it became available. There are over 4,500 viral sequences currently deposited, with around 10 Indian strains in this database. What we see is, that over time, there is some variability in the strains. That is to be expected, as all viruses develop mutations as they transmit from person to person.
What is not being observed so far is any mutation on any of the important sites of the virus, such as the spike protein or in the RNA polymerase or protease enzymes, which are relevant for drug targeting and vaccines. Those sites have not shown any major mutation, so we believe whatever strategies are now being used to develop both therapeutics or vaccines are not threatened by any changes we are observing in the virus. In other words, there are minor mutations that occur as viruses evolve.
We can also use sequence data to track movement of the epidemic. For example, in Washington State, when they found a number of cases in a nursing home, they were able to go back and look at the strains of the first case in the state which was a traveller from China, and they found there was a match. So they could deduce that the infection had come from China in early January, and had been circulating silently. The genetic sequencing helps us track the epidemiology and how it’s spreading in the community, and in between countries. By tracking, we can see if there are changes significant enough to alter the virulence. We are only three months in so it’s early to say, but it is really important that we keep tracking it. This is especially important for vaccines. For example for the flu, every year you have to pick the strains for the vaccine, which is a completely different scenario than having a stable virus for which you can develop a universal vaccine that will be effective.
What does the evidence tell us about the effectiveness of lockdowns as a strategy?
The WHO has laid out quite clearly that physical distancing, of which one extreme form is a lockdown, does help dramatically reduce interactions people have with each other and brings down the transmission of the virus in the population. What they saw in China [after locking down] was transmissions within households were still going on, so they then took an additional step that was basically testing everyone with symptoms, and taking those who were positive to a separate facility where they could be kept and treated, and the exposed persons to a separate quarantine facility. In other words, moving from house quarantine to facility quarantine. We need to think about this in terms of the logic for doing that, which is if you are living in a crowded setting, chances are you are more likely to transmit to others. Other public health interventions that are shown to be effective like handwashing, disinfecting surfaces, covering the face and mouth when coughing, and usage of masks need to be all implemented together, to be effective. We also need to remember that we are going to be facing this infection for a long time, and will need to think of sustainable strategies, as we exit lockdowns eventually. People will need to change behaviour — continue to follow physical distancing, isolate if sick, improve personal hygiene, while the public health system will need to detect, isolate, treat and track cases.
We have been hearing different recommendations in different countries on facemasks. Should everyone wear a mask?
It is clear that anybody who has symptoms should be wearing a mask. There have been many studies done in the case of influenza, where people with symptoms who wore masks and washed hands significantly reduced spread to household contacts. There is no doubt about that. There is also no doubt that healthcare workers need to wear masks and proper Personal Protective Equipment (PPE) as they are the ones likely to see a lot of infectious patients.
When we are talking about the general population, the logic there is if you don’t show symptoms but you still have the infection, you can still be spreading it. That is the logic for everybody wearing a mask. Asymptomatic people spreading infection is not the bulk of transmission and whatever studies we have seen till now suggest it is not more than 10 to 15 %. Of course, we can argue even that is important and you want to reduce that. Another school of thought is you don’t stigmatise anyone if everyone wears a mask.
People should remember that wearing masks does not protect the wearer of the mask, but protects others. If you speak forcefully or sneeze, the droplets won’t travel as far because the mask will keep it in. There is no evidence that ordinary surgical or cloth masks will protect the wearer from getting an infection. There have been studies that show people wearing masks end up touching their face more, which is another thing to keep in mind while advocating mask use. Also, people should not become complacent just because they are wearing a mask.
The WHO put out an update on masks and indicated that it is for countries to develop their own public policies, based on the current state of knowledge. We encourage the collection of data so that other countries can learn from the experience of one. The caveat is that you have to do the other things as well, such as hand washing. Wearing masks does not protect the wearer. You are wearing masks to protect others, so it’s more of a social good.
Lockdowns impose high collateral economic costs, which are harder for some countries to bear. There is also the risk of an increase in deaths from other causes because of making it harder to access medical resources. What’s your view on how countries can approach this trade-off?
I don’t think there is a clear answer and different countries have used different approaches. The economic and human cost of lockdowns need to be minimised, by ensuring that essential needs of citizens are met. One thing to remember is a lockdown alone cannot be effective, unless it is combined with standard public health measures. Most important is knowing where the virus is and tracking various sources of data to find it. The success of China was based on a lockdown plus all those other measures. Going house to house looking for cases, isolating them and treating them, and following contacts. Stepping up diagnosis and surveillance. Constantly updating people and informing them about the logic and need for drastic actions.
Not just India, but every country is facing a shortage of diagnostic kits. What are the other measures that can be used to track disease? Number of admissions of pneumonia and influenza like illness, how many people with fever are seeking care, deaths occurring at home and in the hospital, PMJAY claims etc. In New York city, influenza like illnesses, which normally start falling in early March, after the winter peak, started rising instead this year. Real-time tracking of epidemiological data and analysis of the various health information platforms that exist can help provide clues as to where the epidemic is going. These data will also answer other questions, like whether you are seeing trends in collateral effects, deaths due to heart attacks or strokes going up, how we are dealing with other infections diseases that are not going to go away, such as tuberculosis. For example, in the U.S. we have seen one company that has digital thermometers that can track temperatures and aggregates all the data, which maps how fever is distributed across the U.S. You can then see where the next hotspot is likely to be.
Perhaps we can consider using the Aarogya Setu app [which lets users know if there are COVID-19 cases in locations close to them] for other applications, such as tracking fever or access to care. If you have symptoms, you should be able to find out the nearest testing centre, which should be kept away from hospitals, so you can get tested and get the results. The penetration of mobile phones is so high in India we can think of using it to track symptoms, while avoiding any kind of social stigma, which you may get from the traditional way of putting notices on people’s homes. We can think of getting people to sign on voluntarily to this kind of app, while being transparent about how the data is used.
People are making enormous sacrifices. Community involvement and participation, understanding, and cooperation with what the government is doing is needed to achieve the end result. We also need to be sensitive to the needs of the poor and vulnerable, and ensure that their food and other basic necessities are met. Police and enforcement authorities need to be sympathetic while being firm, and good communication about dos and dont's is important.
Should India be testing more broadly?
Data is key to the control of this pandemic. As we go ahead, we need to expand the number of people who are being tested — the more, the better. The fact is, because of shortage of testing kits, we cannot simply test everybody, even if we wanted to. One way is looking at sentinel surveillance where you test a proportion of people with influenza like illness (ILI) or Severe Acute Respiratory Infections (SARI), which the ICMR is already doing. If we can keep up that kind of sentinel surveillance even if you cannot test every pneumonia patient in the country, we can know the state of the outbreak.
Serological testing is also beginning to be used in many countries, from which you can get an idea of the extent of the population exposed and also the geographic spread of the virus. With a nationwide serological survey on a sample of people from every district, making sure you have age and other considerations, we can have a map of the spread across India. We know there are cases in 250 plus districts but we don’t know if 400 other districts are clear. Serological testing will tell us that, and it can be repeated periodically to give us an idea of how the outbreak is evolving.
A lot of people have talked about herd immunity, the idea that a large proportion of the population will develop antibodies after natural infection. I have seen one study come out, and a few more are coming out, that tell us even in a highly prevalent district in Germany, the prevalence of antibodies was 15%. In less affected areas, that will be 5% or less. So, a majority of the population is still susceptible and not immune. Ultimately, only a vaccine can provide enough herd immunity to protect the entire population.
Is there any evidence to suggest Hydroxychloroquine, which some countries are prescribing as effective treatment, should be included in the treatment protocol?
What we at the WHO did right from the beginning was start tracking therapeutics. We developed a database from various sources and had an expert committee that looked at prioritising which drugs were promising, based on either in vitro (laboratory) data that showed a drug had some activity against the virus, or data from other coronaviruses such as MERS or SARS. Some that have been tried so far are Chloroquin, Lopinavir plus Ritonavir, Remdesivir, and interferon-beta as an adjunct, which was tried for MERS. Monoclonal antibodies proved very effective in Ebola, and some companies are developing monoclonal antibodies against COVID-19. The Solidarity trial launched 10 days ago is comparing Hydroxychloroquine, Remdesivir and Lopinavir/Ritonavir with and without interferon-beta. The goal is to include more treatments as they come through and collaborate closely with groups around the world as they develop new therapies. The approaches are to find an antiviral drug, monoclonal antibody treatment or an adjunct therapy that helps modulate the body's response to the virus.
There is currently no drug with proven efficacy against COVID-19. Some are being used on a compassionate-use basis, and not based on scientific evidence. But in the coming weeks, we will have results from clinical trials which should inform us.
Some countries, such as India and China, have recommended traditional medicines or Ayurveda as effective immunity-boosting treatments. Is there evidence to suggest this can help against COVID-19?
Traditional therapies need to be subject to the same standard and undergo rigorous trials. In China, clinical trials have been registered for some traditional medicines. In India, a committee has been set up to look at potential Ayurvedic medicines, and it’s a good thing. It could be used potentially in early disease to prevent progression, or in prevention of infection, but that needs to be subjected to the same kind of rigorous clinical trials and evidence. The same standards should be applied to traditional and allopathic treatments.
It’s one thing to say these treatments can boost your immunity, but it’s quite different from saying you will be protected against a specific virus. Many traditional practitioners are saying this will boost your immunity, and that’s fine. But messaging about these medicines being specifically effective against COVID-19 needs to be demonstrated through studies.
At this point we should have a very open mind and encourage research that explores all types of treatments. But this should be in properly designed and properly conducted research studies.