Dra. Ana Luisa Mendizábal Méndez.
Vaccines: Understanding the Relationship Between COVID-19 and Previous Pandemics
The 1918-1919 pandemic, also known as the “Spanish flu,” was caused by the influenza virus. Since then, we have faced two epidemics caused by viruses from the same family: the SARS-CoV coronavirus, which caused an outbreak in China and 26 other countries from 2003-2004, and the Middle East Respiratory Syndrome (MERS) outbreak that affected 27 countries in the Arabian Peninsula from 2012 to this year. Although the number of MERS cases was lower (2519), the mortality rate was approximately 35%.
There are many similarities between the SARS-CoV, MERS-CoV, and the SARS-CoV-2 virus responsible for COVID-19. Understanding these similarities can help us develop effective vaccines against COVID-19 and prepare for future pandemics.
Understanding the Coronavirus Pandemic: How Vaccines Can Combat Its Spread and Clinical Effects
But the most worrying thing is that there is no vaccine available in the market for any of these viruses, available to the population. In the case of SARS-CoV, despite the last case being recorded in 2004, eight years later, in 2012, the Centers for Disease Control and Prevention of the United States (CDC) classified it as a “select agent.” A select agent is a bacterium, virus, or toxin that has the potential to pose a serious threat to public health and safety. Despite this and despite the fact that 33 vaccine prospects were registered for SARS-CoV, only 2 reached phase I, that is, they were tested in small groups of adults, none of which were launched on the market.
The main reason was that while the vaccines were still being developed, cases stopped being reported, so launching a vaccine for a disease that “no longer existed” was not economically viable. The next question would be: if cases of MERS have occurred until early this year, with such high mortality.
Covid in India: An Example
India has been one of the countries hardest hit by the COVID-19 pandemic, with over 47 million confirmed cases and over 600,000 deaths as of March 2022. The article discusses how the government has responded to the pandemic, including measures such as lockdowns, travel restrictions, and vaccination campaigns. It also covers the challenges faced by the healthcare system, including shortages of medical supplies and personnel.
On the other hand, India has a population of over 1.3 billion people, which makes it the second most populous country in the world. As such, any information related to COVID vaccines in India is likely to be of interest to a large audience.
Why is there no vaccine against it?
Only in September 2019, The Lancet published the results of the first phase I trial of a vaccine against MERS developed by two laboratories and the Walter Reed Army Institute of Research called GLS-5300. In the study, 85% of participants had immunity to the virus up to a year later and 97% suffered mild adverse reactions such as:
- general discomfort
- pain at the injection site, which are quite common in many vaccines used today.
However, the second phase of the study will not be completed until November of this year
It is necessary to take into consideration that due to the extent and severity of the pandemic caused by SARS-CoV-2, coupled with unprecedented media attention, there is great pressure on governments and pharmaceutical companies to create a vaccine against a virus about which relatively little is known. There is limited history and so far no strong scientific evidence for the development of vaccines against other viruses in the same family. In addition, although it may sound drastic and constitute an ethical dilemma, the cost-benefit or return on investment of the research cost is not known.”
Virologist Chris Smith from the University of Cambridge, along with other professionals in the field, warns that vaccines present their greatest benefit when applied as prevention against an expected disease outbreak rather than during the peak of an unknown microorganism.
In addition to the costs of millions of dollars in research, there is a possibility that by the time the vaccine is ready, it may no longer be necessary or inadequate for treating subsequent outbreaks.
During the 1918-1919 pandemic, there were 3 outbreaks, the second of which was the deadliest, with approximately 50 million deaths. The Asian flu, which had multiple outbreaks between 1957 and 1959, claimed approximately 1.1 million lives.
While it is certainly desirable to quickly find effective vaccines or treatments against SARS-CoV-2, we must be aware that this may be a lengthy process and, for the time being, the control of the pandemic, the emergence of new outbreaks, and their consequences depend largely on the joint efforts of society. Maintaining social distance, social isolation, washing hands correctly and frequently, among other measures, are of vital importance for controlling the present COVID-19 outbreak and preventing or limiting subsequent outbreaks.
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