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Revisiting vaccination in the era of Covid-19

19 Dec, 2020 - 09:12 0 Views
Revisiting vaccination in the era of Covid-19

The Sunday Mail

AS the deadly coronavirus continues to wreak havoc across the globe, vaccination has increasingly become very important to urgently save lives.

By December 16, there were reportedly 74 441 369 confirmed Covid-19 cases, 52 224 001 recoveries and 1 653 221 deaths worldwide.

According to the World Health Organisation, vaccination currently prevents 2-3 million deaths every year. In the absence of Covid-19 vaccine, the global economy will approximately lose US$3,4 trillion in GDP annually.

Vaccines contain weakened or inactive parts of a particular organism (antigen) that biologically trigger an immune response within the body.

In fact, the weakened version does not normally cause the disease in the person receiving the vaccine. It, however, prompts the immune system to respond in a similar manner it would have initially reacted to the actual pathogen.

And some vaccines require multiple doses, routinely given in weeks, or months apart.

Coronavirus, a deadly infectious disease, has since necessitated the development of a vaccine. The initial vaccination will equally come in two doses.

On December 11, 2020, the United States authorised the Pfizer-BioNTech mRNA Covid-19 vaccine for emergency use. The drug has apparently been approved for emergency use in other countries such as Canada.

In China, the CanSino adenovirus and Sinovac inactivated vaccines have been approved simultaneously, albeit with limited use. And in Russia, the Gamaleya adenovirus vaccine is primarily in early use.

History of vaccination

Historically, the concept of vaccination dates back to hundreds of years ago. Buddhist monks traditionally consumed snake venom to confer immunity to snake bites.

During the 17th century, the Chinese practiced variolation – the smearing of a skin tear with cowpox to give immunity to smallpox.

In 1796, English physician, Edward Jenner inoculated a 13-year-old-boy with vaccinia virus – cowpox. He demonstrably conferred immunity to smallpox.

And in 1798, the first smallpox vaccine was subsequently developed. Over the 18th and 19th centuries, Jenner systematically implemented mass smallpox immunisation which culminated in its global eradication by 1979.

In 1897, Louis Pasteur experimentally spearheaded the development of live attenuated cholera vaccine. And in 1904, he similarly inactivated the anthrax vaccine in humans.

Likewise, the Plague vaccine was also invented in the late 19th century.

Between 1890 and 1950, bacterial vaccine development proliferated, including the bacillus-calmette-guerin (BCG) vaccination, which is still in use today.

In 1923, Alexander Glenny scientifically perfected a method to inactivate the tetanus toxin with formaldehyde.

In 1926, the method was similarly used to develop a vaccine against diphtheria. And in 1948, a whole-cell vaccine against pertussis was apparently first licensed for use in the US.

Herd Immunity

Essentially, it is not everyone who gets vaccinated. Nevertheless, the unvaccinated can still be protected if they live in, and amongst the vaccinated.

People with underlying health conditions that weaken the immune system, or who have severe allergies to some vaccine components may not get certain vaccines.

But, when a lot of people in a community get vaccinated, the pathogen has ostensibly a hard time circulating.

So, the more people are vaccinated, the less likely the unvaccinated are exposed to the harmful pathogen. And this is called herd immunity.

Of note, no single vaccination provides 100% protection. Likewise, herd immunity does not provide full protection to those who cannot be safely vaccinated.

But with herd immunity, the unvaccinated will substantially have some form of protection.

Today, physical distancing, the use of masks and test, track and trace programmes are currently the most effective measures against the spread of coronavirus.

Vaccine-nationalism

Though success has been largely recorded in the development of Covid-19 vaccine, vaccine-nationalism is likely to further compound the manufacturing and distribution process.

History shows that national governments tend to follow their own interests instead of pursuing a more globally coordinated approach.

Vaccine-nationalism occurs when countries inconsiderately push to get first access to a supply of vaccines. However, there has been international cooperation under the auspices of COVAX.

The WHO and other international institutions have sincerely cooperated to provide equal access to vaccines globally by pooling resources.

Regrettably, there have been patently weak commitments from wealthier countries.  As such, vaccine-nationalism could cost the global economy approximately US$1, 2 trillion a year in GDP.

And if the poorest countries fail to access vaccines, the global economy is likely to lose between US$60 and $340 billion annually in GDP.

Vaccine testing process

Preclinical testing: scientists test a new vaccine on cells and subsequently give it to animals such as mice, or monkeys to see if it produces an immune response.

Phase 1: scientists give the vaccine to a small number of people to test safety and dosage, as well as to eventually confirm that it stimulates the immune system.

Phase 2: scientists give the vaccine to hundreds of people split into groups, such as children and the elderly, to see if the vaccine acts differently in them.

Phase 3: scientists give the vaccine to thousands of people and wait to see how many finally become infected, compared with volunteers who received a placebo.

Early or limited approval: countries begin to decisively grant emergency authorisation to vaccines based on preliminary evidence of safety and effectiveness.

Approval: regulators rigorously review the complete trial results and plans for a vaccine’s manufacturing, and decide whether to give it full approval.

More importantly, vaccines have historically reduced the burden of infectious diseases. And experts have systematically proved that vaccines are safer than therapeutic medicines.

Critically, vaccines have an excellent safety record and most “vaccine scares” have been widely shown to be false alarms.

Ultimately, vaccines are among the most efficient tools for promoting individual and public health. And investing in vaccination will crucially save countries millions of dollars.

As we keenly wait for a substantive Covid-19 vaccine, let us observe the recommended preventative and protective health measures.

Everisto Mapfidze is a registered general nurse who holds a Bsc Honours in Sociology (UZ). For feedback: [email protected] or Whatsapp +263774042111.

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