The Indian Council of Medical Research (ICMR) has released the results of the fourth sero survey. The survey was conducted in 70 districts of 21 states in June and July and antibodies against Kovid-19 were found in 67.6% of the people.
The results of the sero survey have come as a ray of hope against the Kovid-19 epidemic, but can it be said that herd immunity has been formed in India? Will there not be a third wave in India? What is the reality of the intimidating mathematical models that have come about the third wave? We spoke to Dr. Gagandeep Kang, the country’s top virologist and professor at Christian Medical College, Vellore, regarding the results of the sero survey and the increasing cases of delta variants across the world. Know in his own words through question-answer what the sero survey figures are saying…
What is sero survey and what do the results of the fourth survey say?
ICMR has conducted blood serum surveys four times so far. It is seen through a blood test that how many people have antibodies against Kovid-19. This shows how much of the population has got Kovid-19 infection i.e. sero-prevalence.
Earlier, ICMR had conducted three surveys. In the first survey in May-June 2020, the sero-prevalence was 0.7%. Thereafter, sero-prevalence has steadily increased. It was 7.1% in the second survey in August-September 2020 and 24.1% in December-January (20-21). Now it has increased to 67.6% in the fourth survey of June-July 2021.
It is clear from the fourth sero survey that Kovid-19 antibodies have been formed in most people. That is, they have got some kind of protection. We also have a low speed of vaccination. In view of this, it is good for us to make antibodies in maximum population.
Are Delta Variant Cases Increasing Worldwide? What will be its impact in India?
The World Health Organization (WHO) says that the alpha variant of Corona is 178, the beta variant 123 and the delta variant is now in 111 countries. But with the rapid spread of the Delta variant, it will soon become the most dominant variant in the world.
The alpha variant is 60% more infective than the original variant of Corona. When it comes to Delta, it is 60% more infectious than Alpha. The good thing is that the immunity built in our body has shown some effect on all the variants found so far. When antibodies have been found in 67% of the population in sero survey, it will prevent us from spreading the delta variant to some extent. Infections will not go away, but the risk of them becoming serious will be reduced.
In how many populations will herd immunity be formed if antibodies or vaccines are administered?
If antibodies are made in 85% of the population, then herd immunity can be formed. We see this by the value of R0. This is the ability of a virus to infect. The R0 value of the original virus was 2.5. Then it was said that if 60% of people have antibodies or are vaccinated, then herd immunity will be formed.
But then came the alpha variant and now the delta variant dominates. Its R0 value is 6.5. In view of this, we can say that antibodies are necessary in 85% of the population for herd immunity. This antibody can be made from natural infection and also from vaccination.
When we look at the sero-prevalence rate of healthcare workers, it has reached 90%. This does not mean that antibodies will be made in everyone. But it can be said that antibodies will work in 85%. Even if they have an infection, the chances of having serious symptoms are very less.
Talking about the general public, the sero-prevalence in it is 67%. About 30% of the population has come under single dose coverage and only 6.5% of the fully vaccinated population. It will take time to reach 80%-85%. During this, the Kovid-19 protocol will have to be followed. Masks, social distancing and hygiene will have to be taken care of.
ICMR has recommended to open schools? Is it true?
Yes. That’s perfect. In the survey, sero-prevalence in children aged 6 to 17 years has reached 60%. That is, antibodies have been formed in their body, but before opening the school, all the teachers and staff should be vaccinated. Children have to be taught to wear masks. There should be good ventilation in the classroom.
The most important thing is that the central and state governments should decide the trigger points. This means that if the case increases, then there should be preparations to close the schools. As the situation arises, decisions should be taken accordingly.
New cases in India have been stuck at 40 thousand for a month. what does this mean?
Cases will keep coming. There is no need to worry about it. If you look at the sero-prevalence data, more than 30% of the population is still not infected with corona. Or they don’t have antibodies. This figure is around 40-45 crores. That is, one and a half times the total population of America. They are in danger of corona.
We have to speed up vaccination in India. The sero-prevalence gap widened in the third and fourth surveys. 45% in rural areas and 35% in urban areas. Sero-prevalence will not increase at such a high speed going forward. That means cases will come.
There may be a third wave, but the good thing is that all the variants that have come so far have had some effect on the already made antibodies and vaccines. For this reason, we can say that if there is no completely new variant that escapes this antibody, then the third wave will not be as terrible as the second wave.
Intimidating mathematical models have arrived on the third wave, how reliable are they?
are not at all. The models they are making do not have any understanding of infectious disease. He is a mathematician. Computers make predictions based on the data. Pandemic study is a very specialized field.
You tell me, will you go to the cardiologist if you have a fracture? No, you will go to the orthopedic. The same should be done about the bus pandemic. This is a very specialist field. Dr. Gautam Menon has created models in collaboration with IISc and other institutions, it is close to reality, there is no prediction in it.