Exclusive interview with Professor K. Srinath,President, Public Health Foundation of India the vaccine will help to save lives reduce transmission , but not throw out the virus from this planet.
Q. Do you think vaccination is the only solution to save people from COVID-19?
A. I do not think it is the only solution but it will be part of the solution. We will require a combination of public health measures over 2021 to see Covid-19 fade away by 2022. We will still need to wear masks for most of next year, avoid super spreader events and follow the norms of hand hygiene and physical distancing to the extent possible. I believe that, with these measures, the virus will change to a less virulent form and pose less of a threat to life even it co-exists with us as many other viruses do. Otherwise, it cannot survive as a species if it keeps ravaging its host species. That is the survival logic of evolutionary biology. In the meanwhile, a safe and effective vaccine will help to save the lives of the most vulnerable persons, such as the elderly, persons with co-morbid health conditions, healthcare providers and other essential workers who are frequently exposed to symptomatic or asymptomatic persons infected with the virus. The vaccine will help to save lives, not throw out the virus from this planet.
Q. How break the chain could be a solution to reduce COVID-19 cases?
A. We must recognise that the systemic vaccines which are administered by intramuscular injection are not yet proven to prevent a person being infected by the virus. They only help the body to mount a strong defence against the virus and prevent a serious disease and death, if infection does occur. Whether an immunised person who acquires the natural virus from an infected person will harbour the virus in the nose or throat for some time and whether that can be the source of infection to another person is unknown at present. It is possible that by preventing a serious symptomatic disease and quickly fighting off the virus in the body, the period of viral replication will be cut short and the immunised person may not be transmitting the virus to others for long. That will help to reduce transmission. However, current scientific evidence does not provide proof that an immunised person will not get infected at all and will not transmit to others even for a short while if infected. Vaccine will save lives, will probably reduce transmission but not completely break the transmission chain.
Q. Who should get the vaccine first?
A. Health workers, other essential workers, elderly persons and persons with pre-existing health disorders (co-morbidities) are the persons who are at the risk of severe infection either because of high levels of viral exposure or lowered immunity due to age and underlying health conditions. They should receive the vaccine first. The challenge lies in identifying persons with co-morbidities. In large cities, many of them would have already been identified, though there too persons in slums and low income communities may have been missed out by the health services which do not routinely screen for these disorders. In smaller towns and villages, the proportion of undiagnosed persons with these disorders would be higher. Since these co-morbidities occur at least a decade earlier in the Indian population compared to the western populations, we should offer the vaccine to all persons above the age of 50 years initially, apart from the essential workers, if adequate vaccine stocks are available.
Q. Do you think India is well prepared for mass vaccination? What kind of geographic strategy India should follow?
A. I do not know what the plans are but believe that the vaccination will occur in stages. That should help in efficiently planning the rollout and managing the logistics. It would be appropriate and efficient to start with the cities which have high crowd density and move outward to smaller towns and villages. These urban areas will also have more persons with co-morbidities and higher age groups. If there are hot spots emerging with high rates of new infection in any area, they too will need to be accorded priority. Within this broad framework, all states should be covered.
Q. Mass vaccination in a densely populated country like India requires how many phases?
A. It depends on the availability of the vaccine and the health workforce needed to administer it. I expect multiple phases of rollout. Broadly the first phase will cover essential workers and persons at high risk of severe disease. The next phase would cover the other age groups at risk sequentially, going down decade by decade and also expanding the definition of essentiality. The third phase would cover the remaining, as a supplement to the routine immunisation programme. Each of these broad phases can have sub-phases. The rollout can be modified by changing dynamics of the epidemic. If the transmission, hospitalisation and death rates drop markedly due to other factors, the urgency of the immunisation drive may ease and we can wait for newer vaccines to arrive with better profiles of protection, safety, logistics and cost. Mass immunisation may not be a required strategy then. This has been an evolving epidemic and our strategy too must be adaptive.
Q.When do you think India will be free from COVID-19?
A. I cannot crystal gaze and predict with assured confidence, because of the multiple variables involved in viral behaviour, human behaviour, speed of scientific progress and nature of governance at state, national and global levels. However, 2021 should be better than 2020, in gaining control. If we provide a strong and steady response, at all levels of society, we should be able to overcome the epidemic by the middle of next year. The virus itself is unlikely to go away, even if it becomes less virulent. So, we need to maintain vigil till the next winter too passes. I expect that we will be able to celebrate our 75th year of freedom in 2022, without the shadow of Covid19 looming over us. Our freedom struggle took strength, resolve and sacrifice to gain independence. Our battle against Covid-19 too will require those qualities of confidence, commitment and resilience.
