‘COVID-19 wave not distinct entity, will come periodically’

Epidemiologist Dr Chandrakant Lahariya on the new variant, vaccine immunity and India’s preparedness 

Taran Deol
Published: Wednesday 01 December 2021

India recorded 8,954 new cases of the novel coronavirus disease (COVID-19) and 267 deaths on Wednesday, a slight rise from the previous day, according to data from the Union health ministry.

Currently, there are 99,023 active cases across the country, a figure that fell below a lakh after over 500 days. 

As many as 80,98,716 vaccine doses were administered on November 20, 2021, of which 25,80,689 were first dose and 55,18,027 second. The total number of doses administered now stands at 1,241,086,850.

With the detection and classification of Omicron as a ‘Variant of Concern’ last week, travel guidelines put in place in India will come into effect December 1, 2021. The Union Minister of Health and Family Welfare Mansukh Mandaviya told Rajya Sabha Tuesday that Omicron has not yet been detected in India. After the deadly second wave earlier this year, the situation has calmed down significantly but what does this new VOC mean?

Dr Chandrakant Lahariya, a public health analyst and epidemiologist, spoke to Down To Earth about India’s preparedness against a possible rise in cases, what must be done, the fears surrounding the new VOC Omicron and waning immunity against COVID-19. 

Taran Deol (TD): Do you see a third wave of COVID-19 coming in India?

Dr Chandrakant Lahariya (CL): It is time we stop seeing a wave as a distinct entity. What we need to remember is that once cases stabilise — come down to a particular low level — then the only direction the figure can go is upwards. 

Now, there remains some uncertainty. The number of cases can go upward, but till what level we really do not know. 

Similarly, when that would happen, we do not know. This will be determined by external factors. So, of course, there is no doubt that there is a possibility of an upward trend, which can be sustained for a few weeks.

TD: Can you detail what these external factors are?

CL: The timing and extent of the upward trend would be dependent upon a number of factors. One, COVID-19-appropriate behaviour of individuals. People can’t keep following COVID-19-appropriate behaviour forever. At some point they will become lax and that is human behaviour.

Second is the emergence of a new variant which can escape immunity and has high transmissibility. The rise would be dependent upon what proportion of people are following COVID-19-appropriate behaviour at the time.

The third factor is the immune status of an individual. Currently, we know vaccines and natural infection provide some protection for a year. But there will come a time when the immunity would start declining. 

Then, people will be more susceptible and if there is an existing variant that can cause reinfection or a new variant that can cause infection, cases will rise.

The fourth and final factor is vaccination coverage. We must examine how to maintain that immunity.

TD: Is India ready for a possible rise in cases?

CL: My argument is based on the way we are seeing dengue and other outbreaks in different parts of the country. For example, currently, most of the health workforce has been diverted from other areas to focus on COVID-19. There will come a point when those essential non-COVID-19 services will need to be resumed. If attention might be diverted from the pandemic, then we will still be unprepared.

So essentially, because we are currently focusing on COVID-19, there is a better response. While a few things have improved, such as testing and beds in hospitals, I would not say that fundamental changes have happened. 

Moreover, the number of cases are unlikely to go as high as they did in the second wave. So knowing that there is high vaccination coverage and less likelihood of moderate to severe disease, India is better prepared. 

But for the long term, this is not what I would call a better preparedness. In a hypothetical scenario, if we see similar kinds of challenges as we did during the second wave, I don't think the response is going to be very different. 

For this, we need a stronger healthcare system and long-term investment. The government must fulfill the promises made during the 21 months of the pandemic.

TD: The World Health Organization (WHO), citing preliminary evidence, has warned of a rise in reinfections due to Omicron…

CL: Omicron has been declared a VOC because it has a number of mutations which have been found to be associated with the different characteristics such as immune escape, high transmissibility, differing clinical care outcomes or a reduced response to treatments. In the last 10 days, Omicron became the most dominant — 90 per cent — of all variants, according to data available from Gauteng province of South Africa. I believe this rise in growth is much faster in comparison to delta and other variants.

What the WHO is saying must be put in context. It is too early to say that there is a higher risk of reinfection or immune escape. However, this is a good opportunity to review the situation, re-examine some factors for other variants and boost up preparation in the pandemic response in all settings, including India.

TD: Is immunity against COVID-19 waning?

CL: What we know right now is that antibody level declines over a period of time, be it from a natural infection or vaccination. What we also know is that in this disease, it's not only the antibodies but also cell-based immunity which help fight the infection. 

However, these are not measured and doing so is an invasive process.Various studies have shown that protection lasts for at least 9-12 months. We don't know if it can last longer than that because the vaccines have been in use for a year only.

The second and most important part, in my opinion, is that while studies have found that antibody levels decline over a period of time — and do so variably with different types of vaccines — they also show that protection against severe disease, hospitalisation and death remained almost unchanged. 

We need to remember that the purpose of vaccination is to prevent severe disease and death. So, against the original objective of vaccination, there is barely any decline in protection and that is why we should wait for more evidence before having a discussion on booster doses.

TD: Will there be efforts to tweak the vaccine to be more effective against new variants? 

CL: Tweaking vaccines is a natural process. Whenever vaccines are formulated, and especially in such settings, they are called first generation vaccines. Irrespective of what the situation is, manufacturers and researchers always try to improve vaccines. 

Now, this virus is regularly changing and some new variants are emerging. So, of course, the right approach is to develop vaccines which are multi-valent, which means it can cover multiple variants. 

There is also an ongoing global discussion about variant-neutral vaccines. This essentially indicates the use of futuristic technology and artificial intelligence to predict which variant could emerge and what its characteristics could be.

In a study published in Science, an evolutionary virologist said that future vaccines would definitely have multiple variants. But it is also possible that every few years, a newer vaccine at that point of time could be very different from the original vaccine.

TD: Anecdotal evidence from South Africa indicates that Omicron causes mild symptoms. Does this mean the COVID-19 pandemic is becoming endemic?

CL: The variant doesn't cause the pandemic to become endemic. The only way this can happen is when people have developed immunity either after natural infection or vaccination. The susceptible pool of individuals must go down. We don't want that to happen because of a natural infection but by vaccinating people. 

If the virus cannot find enough susceptible hosts, it will not be transmitted. Then, only a few susceptible hosts will remain. These include people who are either immunocompromised or whose immunity has declined or who do not develop an immune response even after vaccination. All of these factors will come into play.

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