OPINIONS

Third Wave and Vaccine Hesitancy

By Dr Amit Thadhani

In India, the second COVID-19 wave is still in progress in several states. Arunachal Pradesh has the highest number of affected districts (17), followed by Rajasthan (11), Meghalaya (9), Kerala (8), Andhra Pradesh (8), Manipur (6), Nagaland (5), Odisha (4), Assam (4), Tripura (4), Sikkim (3) and Mizoram (2). It may be noted that the number of cases in Kerala continue to be significantly high at over 15,000 new cases daily. Some districts of Maharashtra such as Satara, Ratnagiri, Raigad and Pune too have had significantly rising cases in the recent couple of weeks. There are altogether 91 districts that are reporting more than 100 cases daily, constituting 80% of the total daily case burden.

The share of COVID-19 burden from rural districts has been consistently above 45% despite under-testing and under-reporting from rural areas, indicating that the spread of SARS COV2 has reached the most interior villages. Once the organism is present widely in the community, it is inevitable that the disease would resurface sooner or later to target the vulnerable in that community.

When this happens simultaneously and rapidly over a large area, it is termed a “wave”.

Europe, US, Israel, the Middle East have already had three COVID-19 waves and seem to be heading for a fourth. France has already had four COVID-19 waves. Hence it can be assumed with a fair degree of certainty that India will sooner or later enter a third wave. Several experts have speculated whether the impending third wave would affect more children or young adults. As of now, there is no evidence that children would be more severely affected by the widely circulating delta strain. Although paediatric ICUs were running full in Mumbai during the second wave, it was more due to the large number of cases overall rather than in this particular age group. It is well known that elderly and vulnerable are at high risk for developing complications and hence this group was prioritised along with healthcare and frontline workers for vaccination.
Unfortunately, because of vaccine hesitancy and intermittent availability issues, this group continues to have a high mortality due to a large number of unvaccinated persons.

PREDICTIVE MODELS

Researchers from Indian Institutes of Technology in Kanpur and Hyderabad came up with a predictive model for the third wave, which puts forward three scenarios from a worst case of up to 2 lakh new cases a day to a best case of under 50,000 new cases a day across the country. This is hardly of any help, as it says nothing much about which scenario is more likely.
The IIT-K study also factors in existing serosurveys and projects that in the worst-case scenario, 50% of infected people could lose their immunity after three months whereas in a best-case scenario, 40% of infected persons lose their immunity while 30% become immune by virtue of mass vaccination. An intermediate projection of up to 75,000 daily COVID-19 cases too assumes that 50% of infected persons would lose immunity, but 25% would become immune one month after the first vaccine dose and another 25% one month after the second dose. It also assumes that a milder less transmissible variant would be in play. The ICMR has done a study in collaboration with the Imperial College of London, in which it is claimed that a large third wave is unlikely and would entail at least 30% of people losing their existing immunity.

However, these projections do not seem to match with actual data which shows that only 5-20% of infected people lose the immunity within eight months. The fear is that this may increase to 40% for delta and 50% for delta plus variants as far as natural immunity is concerned. While this may be true for asymptomatic infections where antibody titres are generally low, the protective effect of vaccines against these variants is much higher and reduced efficacy does not lead to increased hospitalisations or higher mortality, as we shall see later in the article.

Whatever be the scenario, one thing is certain: that we will have a third wave. The extent and severity would depend on a variety of factors. The severity of disease is a much more important factor than the total number of cases. If there are a huge number of cases but hardly any hospitalisations or deaths, there is effectively no public health menace. However, if a more lethal strain emerges and runs riot in a vulnerable population group, we can be in for serious trouble despite fewer number of cases. Hospitals across our country were overloaded when only 2% of the population was diagnosed with COVID-19. Due to our large population, the overwhelming of medical infrastructure in an outbreak remains a serious concern.

EXPERT OPINIONS

Several virologists have also expressed conflicting opinions on whether we would have a third wave. Noted virologist at Christian Medical College Vellore, Dr. T Jacob John has expressed his view that there would probably not be a large third wave if people follow protocols. However, Dr John had also stated in February 2021 that there would not be a large second wave. In December 2020, Dr Gagandeep Kang, also a senior virologist at Christian Medical College Vellore, stated, “I don’t think the exposure is enough to say that we have herd immunity and won’t need to worry about it again, but I think it is enough to ensure that we will have some level of protection so that the transmission will not be as rapid as was seen the first time and the peak will also not be as high”. Dr Kang is now saying, “I am not sure if there is going to be a third wave. There could be seasonal variations”. Very few experts have been on the dot when it comes to COVID-19 forecasting. AIIMS Director Dr Randeep Guleria had warned as early as last year that India was vulnerable to a second COVID-19 wave, and has now stated that a third wave is not only inevitable but could be upon us within just a few weeks as people have again started blatantly violating COVID-19 protocols.

VIRAL MUTATION

Viral mutations are errors in replication seen in the natural lifecycle of all viruses. Most viral mutations are either fatal to or of no significance to the virus but a few may result in new properties that are not present in the original strain. COVID-19 viruses by and large show a large number of mutations and hence, the emergence of mutant strains is not unusual. The concern is whether the new mutant strain has properties that make it more virulent, transmissible and/or capable of evading the immune system and vaccination. The major strain presently circulating in India and across almost a hundred countries is the Delta strain, which has acquired some properties that help it spread faster. The question is whether this delta strain can evade natural immunity or vaccine-induced immunity, and cause moderate-severe disease in previously immune individuals.

WILL CITIES THAT HAD LARGE NUMBER OF CASES STILL SEE ANOTHER WAVE?

The answer probably lies in serosurveys. In February 2021, a large serosurvey found antibodies in an estimated 21.5% of the population. This was before the second wave struck. By June 18, 2021, the second wave had died out and another serosurvey was done jointly by the WHO and AIIMS. The survey found seropositivity rates were almost equal in persons below 18 years of age (59%) and above 18 years of age (67%). In urban areas, the seroprevalence was 78 percent in persons below 18 and 79 percent in persons above 18 years of age. In rural areas, the seropositivity rate was 56% in persons below 18 years of age and 63% in persons above 18. It was also found that 51% of children in Mumbai had antibodies. An astounding 88% of population of Gorakhpur had antibodies. Areas showing such a high seropositivity would most likely not see a fresh outbreak in large numbers any time soon.

As mentioned earlier, it is likely that antibody titres detected in these serosurveys would decrease by 40% to 50% over a few months especially in people who have been asymptomatic throughout. Even if the numbers decrease by 50%, it can be assumed that approximately 30% of population would still retain antibodies against SARS COV2 and thus have some degree of immunity. The number of symptomatic patients is less than 3% of the population of the country. To attain herd immunity status, India needs to have approximately 80% of population resistant to SARS COV2. The safest way to achieve this is vaccination.

MASS VACCINATION

India is now the second most vaccinated country in the world after China in terms of doses administered. Over 38 crore shots have been given in just six months. 21.5% of population has already received at least one dose of the vaccine. At present, India is consistently administering more than 40 lakh vaccination doses per day. States like Rajasthan, Maharashtra, Uttar Pradesh, Karnataka, Kerala, Uttarakhand, Ladakh, Tripura, Himachal Pradesh, Delhi and Rajasthan have vaccinated a substantial proportion of their population. Effectively, once we cross the 60% landmark, we would be close to ensuring that there is no large or lethal third wave that will overwhelm the healthcare system and life can start going back to the pre-COVID-19 normal with some precautions.

RISE OF COVID-19 VARIANTS IN VACCINATED COUNTRIES

Countries such as UK, Israel and USA have vaccinated a large proportion of their population with at least 80% having received one dose. However, these countries are seeing fresh outbreaks, mainly of the delta variant. It is important to look at the data in terms of hospitalisations and mortality rather than absolute numbers, for the simple reason that the cases are not leading to a surge in admissions or mortality. For example, in the UK, where over 80% of the population has received one dose and 60% has received two doses of the vaccine, over 25,000 fresh cases per day are being detected. However, the number of hospitalised patients is very low at 1.4% and mortality is barely 0.07%. Test positivity rate is below 2.5%. Two thirds of hospitalised patients are unvaccinated, an astronomical number in a country where 80% population that is at least partially vaccinated.

(Source of charts and data for UK: https://coronavirus.data.gov.uk/)

When we compare the distribution of people who have received at least one dose of vaccine with the areas of fresh outbreaks, it can be observed that the highest vaccinated areas by and large have comparatively fewer cases.

(Source of charts and data for UK: https://coronavirus.data.gov.uk/)

 

(Source of charts and data for UK: https://coronavirus.data.gov.uk/)

It can also be observed that although there is a steep rise in fresh cases, the overall mortality graph continues to remain flat, indicating that the goal of reducing the significance of COVID-19 to that of a common cold with very low mortality is being achieved with great success. As of now, vaccines are continuing to work well in preventing hospitalisations and death due to variants.

(Source of charts and data for UK: https://coronavirus.data.gov.uk/)

 

(Source of charts and data for UK: https://coronavirus.data.gov.uk/)

VACCINE HESITANCY

The only thing that stands in the way of India attaining herd immunity status is vaccine hesitancy. Less than 50% of the most vulnerable 60+ year population have been vaccinated, the lowest percentage being in Tamil Nadu at just 17%. Overall, only 9.3 crore doses have been administered out of a total requirement of 27.4 doses for 13.7 crore population, and a lot of these are second doses. This was the first group to be offered vaccination and the plateauing of numbers is not a good sign. There is a role for targeted campaigns to encourage vaccination of the remaining 60+ year vulnerable population. Several people in this age group suffer from ill-health and are confined to home. We now have enough experience with vaccination to know that home immunisation can be done safely and efficiently. The Government must seriously consider a more liberal approach towards this, although some steps have been taken to allow vaccination drives in residential complexes.

The number of persons having received at least one dose of the vaccine in the 18-44 age group now stands at 12.2 crores out of 59.4 crore and this number will continue to rise sharply as hesitancy is low in this group. One third of people in the 45-59 age group have received at least one dose of vaccine and this age group is continuing to show up in large numbers, which is very good news.

Vaccine hesitancy in rural India was triggered by a combination of fake messaging on social media and blatant anti-vaccine propaganda by many politicians, so-called social activists and religious leaders. It is fortunately fading away rapidly as rural India was hit significantly by the second wave. Some states such as Uttar Pradesh have incentivised vaccination by offering rations and allowing vaccinated shopkeepers to keep their businesses open. More innovative strategies are needed to reach out to the most vulnerable groups as this segment is the most likely to fill out intensive care beds in the event of a third wave. Simultaneously, rumour mongers should be booked under the provisions of the Epidemic Act.

CONCLUSION

A third wave is inevitable. The magnitude of the next wave depends on how many people we can protect before it starts, as well as the degree of compliance with COVID-19 protocols. Its mortality depends on how much we upgrade our existing medical infrastructure to manage patients in large numbers. India is already the second most vaccinated country in the world in terms of doses administered but due to our massive population, this is nowhere close to what we require to eliminate COVID-19 as a national health emergency. All-out efforts need to be made for eliminating mortality due to COVID-19 and hence mass vaccination and overcoming hesitancy must take highest priority. Data from highly vaccinated countries confirms that the goal of reducing the threat from COVID-19 to that of a seasonal common cold is being achieved as hospitalisations and deaths remain low despite rising number of cases. Strategic targeting of the over-60 population group including allowing home vaccination for this age group should be considered. Paediatric vaccination for COVID-19 will eventually need to be done to achieve herd immunity status, but can be deferred at present due to very low mortality and morbidity in this age group. Incentivising vaccination can help reduce hesitancy in the lower socioeconomic strata. The outcomes of strategies for this incentivization should be studied and replicated widely if found successful.

Author is a reputed general surgeon with an experience of 21 years. He tweets at @amitsurg

(The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of The True Picture. The writers are solely responsible for any claims arising out of the contents of this article.)

 

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