News Brief
Coronavirus Third Wave Inevitable, Says Principal Scientific Adviser K VijayRaghavan: Why Do Pandemics Come In Waves?
- The COVID-19 virus is evolving fast because it has infected large number of people around the world.
- High levels of circulation mean higher replication, and more replication means more chances of genetic mutations.
The third wave on the way.
Even as the country grapples with a deadly second wave of the novel coronavirus pandemic, the experts are warning of a third wave.
On Wednesday (5 May), Principal Scientific Adviser to the Government of India K VijayRaghavan said that a third wave of COVID-19 is “inevitable”, given the amount of virus in circulation, reports The Hindu.
“There is, however, no clear timeline on when this third phase will occur. We should be prepared for new waves and COVID-appropriate behaviour, and vaccine upgrades is the way forward,” he said at a press conference.
Why Viral Pandemics Come In Waves
The researchers have noted various mechanisms behind this wave-phenomena in the flu pandemics:
Behavioral changes. For example, mass gatherings during the elections, lackadaisical social distancing, lack of the usage of masks and other protective measures, etc. is also estimated to have contributed to the surge of the cases.
Population heterogeneity where each wave spreads through one sub-population at a time
Waning immunity in the population. The immunity attained can fade away and someone who has been infected once can get re-infected, the PSA said, adding that decreased immunity also contributed to the second wave
Depending on these factors, the second or third wave of a viral pandemic can be more or less deadly than the first one. In the case of the Spanish flu pandemic, the second and third waves were deadlier than the first one.
One major factor was the behavioural change - the movement of troops during World War 1 led to fast spread of the virus - apart from a new variant of the virus.
In India, the second wave has more than double the total positivity rate (TPR) of the first wave.
According to data from hospitals being tracked by the government, 54.5 per cent patients admitted during the second wave required supplemental oxygen, a 13.4-percentage-point increase from last year’s peak.
While the current data shows no increase in the percent of death between the first wave and second wave (case fatality is recorded to be lower than the first wave), the second wave witnessed more hospitalisations of asymptomatic people, more cases of breathlessness. There are also concerns regarding under-reporting of cases and deaths.
The COVID-19 virus is evolving fast because it has infected large number of people around the world. High levels of circulation mean higher replication, and more replication means more chances of genetic mutations. This is why the Principal Scientific Advisor said that a third wave of COVID-19 is “inevitable”, given the amount of virus in circulation.
The current surge in the cases is also attributed to the emergence of new variants like the UK variant (B.1.1.7), the South Africa variant (B.1.351), the Brazil variant (P.1) and the India variant (B.1.617).
Since these mutations are random, it is hard to predict the timing and severity of these waves.
India Today TV quoted Dr Giridhar Babu, epidemiologist and professor at the Indian Institute of Public Health as saying that the third wave is likely to hit India around November end and early December this year. Babu is also a member and advisor to the COVID task force of Karnataka.
Different experts have predicted the second wave to peak by mid-May.
What We Can Do
While vaccines may be slightly less effective against certain new variants, they certainly prevent severe disease and death. Therefore, the long-term solution to deal with COVID-19 is for people to get vaccinated.
Professor VijayRaghavan pointed out that while the nature of the virus was to mutate, the basic precautions against it to break the transmission did not change.
“We have to follow COVID-appropriate behaviour and get vaccinated. The scientific community is working at mapping the possible changes that can occur in the virus to ensure that our preparedness and response remains robust,” he said.
He also said there was a need to update the COVID-19 vaccines to deal with new strains and mutations.
Apart from this, the countries around the world also need to invest in surveillance measures as well the research to understand and document the mutations and new variants of the novel coronavirus.
Meanwhile, the Health Ministry has warned that Bengaluru Urban; Chennai; Kozhikode, Ernakulam, Thrissur and Malappuram in Kerala; Gurugram and Patna districts are registering an increasing trend of the virus for the past two weeks.
“States including Karnataka, Kerala, Andhra Pradesh, Tamil Nadu, West Bengal, Rajasthan and Bihar are showing an increasing trend in daily COVID-19 cases, and an increase in deaths has been noticed in Maharashtra, Karnataka, Andhra Pradesh, Delhi, and Haryana,” Lav Agarwal, Joint Secretary, Health Ministry, said.
