Both Asymptomatic And Pre-symptomatic People Can Transmit Covid-19: WHO Chief Scientist

India and the world should be prepared for a long battle against COVID-19, and devise strategies accordingly, says Dr. Soumya Swaminathan, Chief Scientist at the World Health Organisation. In an exclusive conversation with Rajat Mishra, she said though the situation in India is still under control, the numbers have shown a sharp rise after the lockdown was eased. She also spoke about how WHO plans to ensure equitable distribution of the vaccine, which should be ready by early 2021, the effectiveness of drugs and the need to wear masks properly to tackle the spread of the disease. Excerpts:

Q: With sharp and constant rise in COVID-19 infections, what is your assessment of the situation in India and the world?

We know that this pandemic continues to grow and this virus is highly transmissible. And research has shown that only a very small section of the population has acquired any type of immunity against this virus. So, given that a large proportion of the world’s population is still susceptible to this virus, it is going to spread. We have also seen that several countries, which were once witnessing peak infections, have witnessed a rapid decline in the number of cases after implementing strict measures like lockdown and strict physical distancing norms. However, some other countries who made this a voluntary effort witnessed no peak and there was plateau or steady state. In a country like India with huge population, cases will increase and it is going to be a long-term problem, and we thus need to have a long-term strategy to keep it under check. Lockdowns are not long-term solutions. Our strategy should be to prevent our health infrastructure from becoming overburdened. I will also say that situation in India is still under control. India made early intervention and imposed strict lockdown, but with the lifting of the lockdown cases are shooting up. But still cases per million population are low and deaths per million populations are also low when compared to many other countries. Now our main objective is to keep mortality down. That will be possible only when the health infrastructure is not overburdened, because mortality rises when that happens. It is also important that other health services which were put on hold during lockdown like OPD, Cardio care etc should be functional and restart now.

Q: There are conflicting reports about when this pandemic will peak in India -- ranging from July to November-- before easing off. What is your opinion?

I think there is no point in predicting peaks; things are changing on a daily basis. And for predicting peak, there can be different models, predicting differently on different assumptions. It is also possible that we go through a period of ups and downs for several months. Right now all possible measures should be taken to control rising cases in India.

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Q: Various drugs such as Dexamethasone, Remdesivir and Favipiravir are now being marketed for treating different stages of the infection. How effective are they?

The effectiveness of any drug has to be based on clinical trials. And clinical trials started very early. First, repurposed drugs were used because there was some sort of indication that they might be useful and some drugs may act on a part of the virus. Hydroxychloroquin was dubbed as an effective medicine but now after 4-5 months, it’s pretty clear that it is not. Dexamethasone is effective in reducing mortality in critical cases. It reduced the death rate of the most critically ill (receiving ventilation) and also those moderately ill (receiving oxygen).  This drug had reduced mortality by one-third. In the case of Lopinavir-Ritonavir, we are doing pooled analysis. In the case of Remdesivir- China's study has shown that it is not effective but US based National Institute of Health (NIH) showed it has reduced hospitalisation period from 15 days to 11 days. Now, WHO is doing a solidarity trial. And by next week we will have results of the trial. So, at this point I will say it is good to go by evidence-based studies.

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Q: Given the heated debate over Patanjali’s claim to have produced an anti-Covid drug, what are your views on Ayurvedic medicine or even homeopathy as a potential mode of treatment of Covid-19?

My answer is the same as above, that we have to go by evidence-based studies. It is hard to prove the efficacy of any medicine or drug unless we conduct a study on it. But it is good to try traditional medicines for prevention. I will also add that there should be some scientific rational behind using any medicine or drug.

Q: Oxford University and Astrazenca’s experimental vaccine has entered the final stages of clinical trial. By when do you expect an effective vaccine to be available for public use?

The trial of a vaccine and having vaccine are two different things. Currently, there are 12 vaccines globally that have entered human trials from Phase I to Phase II. Most of them are in Phase I and II and there are two or three which may be entering clinical trials in July or August. And now Astrazenca is doing Phase III of testing but we don't have results of Phase II as of now.  So we still don't know whether this vaccine protects us from the virus. I am hopeful we will have a lot of results within next 6 to 12 months. As far as having vaccine is concerned, I would say if everything goes well we will have it by early 2021. And that would be a record for manufacturing vaccine in the world because the normal, or minimum, time-frame is about five years. Now the next most important step is for the countries to decide that once they do have the vaccine, who will they vaccinate first? And then put a system in place for the vaccination process.

Q: How should the common man deal with the tsunami of information from various sources, both official and unofficial, about this disease?

This is really a strange problem. People are bombarded with messages and information. We at the WHO do publication screening on a daily basis, and we are screening around 1000 publications and 500 papers on an average each day. These all are pre-prints that are put out, and are not peer reviewed or scientifically vetted. So, there is a lot of information circulating through various means. That is why we say we are grappling with both a pandemic and an infodemic. People should depend on reliable and credible information from authoritative sources.

Q: There are concerns that richer nations might monopolise the vaccine, like during the 2009 Swine Flu pandemic. What steps are or can be taken to ensure equitable distribution of vaccine?

We launched ACT-Accelerator two days back with multiple partners such as Bill and Melinda Gates Foundation to ensure equitable distribution of vaccine. The vaccine pillar combines CEPI’s leadership in vaccine development, GAVI’s track record in revolutionizing access and delivery. And for that, we are setting up a COVAX facility. We are pooling resources for this to enable advance market commitments. Under this system, higher and middle-income countries will have to pay while low income countries would get it for free. We have estimated that for this we require $31 billion, of which $18.1 billion is for 2 billion doses of vaccine that we are aiming to deliver by the end of 2021. Around 950 million doses will need to be procured by self-financing high income and upper middle income countries through the COVAX facility. And we will be having a tiered pricing which means different prices for different companies.

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Q: Can asymptomatic cases transmit the virus?

Yes, I would say both asymptomatic and pre-symptomatic people can transmit virus. Asymptomatic means you never have symptoms even though you are positive. Pre-symptomatic is when you are perfectly fine today, but develop symptoms two days later. Which is why we have this guideline for universal use of masks. These masks need to be worn properly. Many people are wearing loose masks and which sometimes hangs below their nose--that is not saving you from any infection. So proper use of masks will have a significant impact on transmission. What we have learnt so far is that there is no single intervention that works, and in fact a combined strategy is needed. Now that we have enough diagnostic kits, testing should be scaled up.

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Q: There are concerns that pregnant women, whose immunity is naturally compromised, are more susceptible to this virus. What steps can they take over and above hygiene, nutrition and social distancing to protect themselves?  

See, as far as precautions for pregnant ladies are concerned, they should take the same precautions as everyone else is taking. There is nothing alarming in case of pregnant women. And good thing is that pregnant ladies who were infected have delivered babies who all are very healthy. So there is no need to panic.

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Special Issue | Covid-19: All We Know, All We Don't