History offers two examples with which to consider the risks and benefits ofSmallpox was a dreaded acute viral disease in the 18th century. As many as 30 per cent of smallpox patients died, and of those who survive smallpox, about 80 per cent had to live with pitted scars on the face and bodies for the rest of their lives.
With the eradication of smallpox, smallpox vaccination also ceased a few years later. Children born in Singapore from 1982 onwards were no longer required to be vaccinated against this disease. Where there is no disease, anywhere in the world, vaccination offers no benefit. However, the oral polio vaccine is composed of weakened but still live polioviruses and can cause polio-like paralysis in 1 in 2.7 million vaccinations. When poliomyelitis was common, the benefit of preventing disease greatly outstripped the small risk of severe adverse events.
Vaccines that produce side effects that are not well tolerated will fail clinical development and will not be marketed. Importantly, our research found that vaccinated individuals who experience side effects do not develop better or higher levels of protection against COVID-19 than those who do not. Side effects do not indicate and are not required for good immunity, contrary to some popular views.