Nandkumar M Kamat
When will the present COVID-19, the new coronavirus pandemic end? That is the most important question on everyone’s lips.
But scientifically any pandemic can end either medically or socially. The decisions to “end the pandemic” are basically not medical but political because the forces of economy and pressure building from society on account of the lockdown fatigue neutralise the medical opinions. Socially means people lose their fear and come out of the restrictions and begin to take risks leading to “social end of pandemic”.
Evidence of epidemics and pandemics is found throughout the history at least for the past 3000 years. Scientists are not sure how all these pandemics ended but they feel that people develop natural immunity over a long period of time. The virulent Spanish flu became less threatening with emergence of a new strain H2N2 in 1957. Small pox, measles, bubonic plague due to yersinia pestis, flu, cholera, have been major killers. The Antonine plague of unknown origin of 165 AD killed five million, the bubonic plague of Justinian killed 25 million or half the population of Europe in AD 541-2, the black death of AD 1346-1353 killed 75-200 million, cholera killed one million from AD 1852-60 , Asiatic or Russian flu killed one million from 1889-90, the sixth cholera epidemic killed eight lakh people in India in 1910-11.
The worst was the Spanish flu of 1918-20 which killed 20-50 million worldwide. It was followed by influenza A of the H2N2 subtype, that originated in China in 1956 and killed two million till 1958. In 1968 Hong Kong flu, caused by the H3N2 strain of the influenza A virus, a genetic offshoot of the H2N2 subtype killed one million. HIV causing AIDS has killed 36 million so far and world has come to live with it as an endemic now after the peak period of 2005-2012.
COVID-19 was first known from October 2019 and there are many uncertainties about the endgame. People are interested to know when the pandemic would end. The logical answer is that it would not end till COVID-19 is fully eradicated like how small pox virus -variola minor was wiped out from Earth with effective mass vaccination. Ali Maow Maalin, a hospital cook in Somalia was the last patient with small pox in 1977. He was treated and cured, and died in 2013 due to malaria.
The scientific answer for end of the present pandemic is that it would end as an endemic with seasonal localised outbreaks or seasonal flu. So, what are people supposed to do till the present pandemic becomes an endemic? The answer is simple – focus on containment, control local transmission and hope for early availability of an anti COVID-19 vaccine to buy some time till the virus loses its infectivity and herd immunity gets developed.
COVID-19 is related to SARS. In 2003, severe acute respiratory syndrome (SARS) emerged but major outbreaks were effectively contained in Hong Kong and Toronto. The efficiency of SARS containment saw only 8,098 SARS cases globally and 774 deaths. It is remarkable that after 2004 there were no new SARS cases. The problem with vaccines against coronaviruses is the lack of long-term immunity which a small pox vaccine provides. Anti-flu vaccines give temporary protection or short-term immunity but even then, the vaccination becomes effective as shown by H1N1 or swine flu containment in 2009. Fortunately, coronaviruses are very specific in targeting the host cell surface receptors like ACE. The best vaccine therefore would be a powerful genetically engineered vaccine. Other vaccines would be based on short term or long-term immunity but no vaccine under development would be available within a year for mass vaccination program.
The fastest route to vaccine development is to get a vaccine that offers at least a short-term immunity thus containing the spread of the virus. Such a vaccine can be made available within six months. The race between USA and China is about such a vaccine production. The Chinese have assured that their vaccine would be made available to the whole world without any discrimination. This seems to be a diplomatic afterthought after failure to contain the COVID-19 outbreak in Wuhan.
The present pandemic would end as an endemic in the words of Scientific American (SA) writer Lydia Denworth (June 2020) – “Unless a vaccine is administered to all of the world’s eight billion inhabitants who are not currently sick or recovered, COVID-19 is likely to become endemic. It will circulate and make people sick seasonally—sometimes very sick. But if the virus stays in the human population long enough, it will start to infect children when they are young. Those cases are typically, though not always, quite mild, and so far, the children appear less likely to develop severe disease if they get reinfected as adults. The combination of vaccination and natural immunity will protect many of us. The coronavirus, like most viruses, will live on—but not as a planetary plague”. For more information interested NT Readers may access special issue of Scientific American on coronavirus free here-https://www.scientificamerican.com/magazine/sa/2020/06-01/