Second wave, Third wave or fourth wave (all delta variant wave) of Covid 19
Dr Asha Shah. M.D Medicine
Professor of Medicine, GCS Medical college, Ahmedabad
Introduction
There was a lot of speculation about the anticipatory third wave. Well it is already well established in many countries. So it is intriguing situation where countries like India are still in second wave, many countries across world are in the midst of third wave and in some countries there is beginning of fourth wave and most dominant variant in all of these waves is Delta variant. So probably they can all be called Delta wave.
WHO statement
WHO Director described the recent data in the Emergency Committee on COVID-19, established under the International Health Regulations (IHR), a treaty that guides global response to public health risks.
He stated on 14th July that the sustained decline in COVID-19 cases and deaths was due to increasing vaccination rates in Europe and North America, but there is concern over the fresh reversal of that positive trend.
He made a statement that“Unfortunately we are now in the early stages of a third wave”,
since the fourth consecutive week of rising cases of COVID-19 globally, with increases recorded in all but one of WHO’s six regions. Deaths are also rising again, after 10 weeks of steady decline. As per him The Delta variant is now in more than 120 countries and he also stated that it is expected to soon be the dominant COVID-19 strain circulating worldwide, if it isn’t already,”
The spread of the Delta variant one of the main factor of the current increase in transmission is also due to increased social mobility and the inconsistent and improper use of proven public health and social measures.
Surge of cases in world due to Delta variant
As per WHO, The Delta variant of Covid-19 has now been detected worldwide. The Delta (B.1.617.2) coronavirus variant originally discovered in India last December has now become the most dominant and worrisome strain of the coronavirus circulating globally. Research indicates that it is the most transmissible variant yet and 60 % more contagious than the Alpha (U.K./B.1.1.7) variant, which itself caused numerous waves of the pandemic around the world. Delta variant has spread to almost 124 countries and has caused explosive outbreaks in many countries or areas with in countries with low vaccination rates.
In the U.S., Delta has quickly become the dominant strain. On July 20, as per CDC estimation, Delta accounted for 83 percent of all new sequenced cases in the country and Delta may be more likely to infect people who are partially vaccinated than other strains, and may also be associated with a higher risk of hospitalization. All these facts were clearly observed in India in the second wave with the Delta virus. A new study in the journal ‘Nature ‘found that the viral load, a measure of the density of viral particles in the body, is roughly 1,000 times higher in people infected with the Delta variant than those infected from previous variants of the coronavirus. In an analysis of 38,805 sequenced cases in England,it was discovered that the Delta variant was associated with a 2.61 times higher risk of hospitalization. These findings correlate with massive number of cases of Covid 19 and increased deaths in India in the month of April and May 2021.
Delta is expected to become the dominant variant globally in the coming months, with the WHO predicting that there could be more than 200 million confirmed cases within a matter of weeks. .
In fact now it is the pandemic of unvaccinated people. It was so previously also but that time vaccines were not available.
The Covid-19 curve in the United States is rising again after months of gradual decline and number of new cases per day are doubled over the past three weeks. This is due to the fast-spreading delta variant, slowing of vaccination rates and public gatherings. More cases are seen in unvaccinated people. The variant has taken over the previously dominant alpha variant, first detected in the U.K. last year, and has caused further waves of infections in Europe and an ominous increase in cases in the U.S where there were 84735 cases on 28th July and 7 day average was 66924 cases.
In Africa, COVID-19 cases are increasing by 20% weekly and quickly the numbers may outnumber the cases documented during the peak of the first wave in July 2020.
Infections are also rising, particularly in Europe and the western Pacific region. Some Western countries have started to ease restrictions as death rates have decreased. But those countries without adequate access to vaccines or those with a slower vaccination rates are facing a deadlier threat.
Indonesia had more than 1300 deaths in a day and it may become Asia’s new Covid epicenter. Hundreds of people have died in self-isolation, possibly because they could not get immediate treatment or were turned away by overwhelmed hospital.
The World Health Organization has already warned that, based on the estimated transmission advantage of the delta variant, “it is expected that it will rapidly take over other variants and become the dominant circulating variant over the coming months.”
In its latest weekly report on Wednesday, the WHO noted that as of July 20, the prevalence of delta variant among the specimens sequenced over the past four weeks was more than 75% in many countries worldwide including Australia, Bangladesh, Botswana, China, Denmark, India, Indonesia, Israel, Portugal, Russia, Singapore, South Africa and the U.K.
In France, the percentage change in the number of new cases over the past week is 223%, 112% in Italy while in Germany the percentage change is 50%. In the U.S., the percentage change in the last seven days is 58% higher than the previous seven-day period
Situation in India
The situation is still bad, data shows, but not as bad as it was when the second wave peaked in the country, when daily new cases were more than 400,000. On May 7, 414188 new cases which was highest number in the second wave was reported in the country and several thousand deaths. Fortunately,after that peak cases are on the declining trend. On Thursday, 41,383 new coronavirus infections were reported and 507 new deaths as per Indian Health Ministry.
As can be seen in the graph there was a sudden and huge surge of cases in India in April and May 2021 and also rapid fall in June.
Nonetheless, after the U.S., India has the second-highest number of recorded Covid cases in the world, as per data from John Hopkins, with more than 31.2 million cases and almost 419,000 fatalities and this is official figure.
A national blood serum survey which tests for antibodies (known as a sero survey) was released before 2 days showed that two-thirds of India’s population have antibodies against Covid 19, although around 400 million of India’s 1.36 billion people did not have antibodies, the survey found and also that 67.7% of the total population and 62% of those who have not been vaccinated have developed antibodies (against Covid). Nearly all age groups above 6 years have antibodies. This shows the extent of virus spread in the second wave.
But what about vaccination rate in India? As it is a country with overwhelming population, it is going to be herculean task to vaccinate all individuals as availability issues and ignorance in rural areas are the hindrances.
As can be seen, only 7% of people are fully vaccinated in India. The efficacy of presently available vaccines in India is marginally less as compared to MRNA vaccines. With 400 million of the population still being susceptible, dropping our guard would be inviting the next wave early. We need to be fully prepared for any subsequent wave. What is happening in Indonesia, Vietnam or the U.K. is an alarm bell that no country can drop their guard and that they need to do everything in their arsenal. We have to remember always and surely the below mentioned sentence which is a hard fact in pandemic.
No country can be safe till every country is safe.
We should be prepared for more variants, till pandemic is declared over. Where those variants will emerge next, nobody knows.
The big question facing India is if Kerala will be the epicenter of the third wave as there is resurgence of cases in southern Kerala though they are rapidly declining in neighboring states. In the fourth sero survey carried out by ICMR it was seen that antibody prevalence was 67.7% nationally but it was only 42.7% in Kerala suggesting that large number of population is still susceptible. There also happens to have large number of elderly population, people with life style diseases like diabetes in the state and there is high density of population also.
India reported 43,654 fresh COVID-19 cases on 28th July, as compared to previous day’s 29,689 daily new cases. It may or may not be a warning sign of things to come but experts are of the opinion that third wave in India may not be as destructive as the second wave. It is also possible that people continue to get infected and herd immunity may be achieved and if there is no new mutation, third wave may not appear but these are scenarios and actual scene is likely to be different. Let us hope it is better then what we think.
Fourth wave of Covid 19 in France
As most parts of the world grapple with the second wave of Covid-19 or are preparing for the possible third wave, A fourth wave of the Covid-19 pandemic has hit France and which is spreading at lightning speed .It is likely that Germany has also started experiencing beginning of fourth wave and so is US, the fourth wave of the COVID-19 pandemic in France is stronger and faster in its impact due to the dominance of the Delta variant of the virus, cases reaching to more than 10000 per day. Government is planning to collect penalty from unvaccinated d people if they try to enter any public places.
Conclusion
Experts are of the opinion that the disease probably will not disappear. They expect COVID-19 could be similar to the influenza virus that re-emerges every year in a slightly different form. They say there are still many unknowns about the novel coronavirus that causes COVID-19, including how often it will mutate.
Many experts believe herd immunity may be elusive for Covid. As we don’t know really what the required level of herd immunity is to keep COVID-19 out of circulation. For some diseases like measles a much higher level of vaccination is required to keep the disease from breaking out where it is estimated that 95 percent of the herd must be vaccinated or immune to keep the disease under control.
There is a possibility of waning immunity in people or emerging new variants, in which cases this disease will be there for a long haul and people should not expect pre-pandemic behavior. It seems sad but it seems to be true in the present condition.
Only thing that can halt the pandemic is vaccination. It is really unfortunate that it is not happening adequately either because of ignorance, anti vaccine thinking or unavailability of the vaccines. This is year 2021.We know science and it is all evidence based medicine. We know vaccine works. How is it not a better option than the possibility of dying alone gasping for each breath? I have seen in TV interview that in western countries, patient on oxygen or likely to on ventilators would be repenting so much that they did not take vaccine or sometimes begging doctors to give them vaccine when they would be in serious condition. Alas! It is 6 weeks late for them. So there was a statement that “take vaccine to not die” and that holds truth for all vaccine preventable diseases including Covid 19.
References:-
https://www.cnbc.com/2021/07/23/
https://nymag.com/intelligencer/2021/07/
https://www.india.com/news/world
https://www.bbc.com/news/world-57907681
https://www.hindustantimes.com/world-news/covid19
