Vaccines

It was as recent as 1885 that Louis Pasteur, a polymath chemist, demonstrated to a skeptical world that rabies could be prevented by a vaccine.  He was not the first to demonstrate the benefits of immunization.  Smallpox immunization (variolation) was introduced into Great Britain in 1721 by Lady Wortley Montagu, the wife of the British ambassador to Turkey. That technique, which used dried material from smallpox scabs, had been practiced in the Middle East and China from the 1100s.  Lady Wortley Montagu saw its value and, against great medical opposition, introduced it to Great Britain. Edward Jenner, a physician in Great Britain in the late 1700s, saw the clinical similarities between cowpox and small pox and noted that milkmaids acquired cowpox in the course of their work but did not get smallpox. Accordingly, he applied the principle of variolation using cowpox virus - obtained from Blossom, a cow, hence the name vaccination - to cross-immunize against smallpox.  In 1796 he demonstrated that immunization with cowpox protected against a challenge with smallpox.  As a result, Jenner’s cowpox material replaced attenuated smallpox virus for purposes of immunization. He probably was not the first to note this inverse association of cowpox and smallpox but undoubtedly was the person who brought it into the mainstream practice of medicine.

Pasteur was well aware of all this; he already had done experiments to demonstrate the value of immunization for chicken cholera and anthrax. However, the dramatic success, using an experimental vaccine on a nine-year old boy, Joseph Meister, who had been bitten by a rabid dog, made him a hero.  It also made vaccination a major tool in the medical armamentarium and catalyzed vaccine research not only in his eponymous Pasteur Institute but also in pharmaceutical companies that developed in the years that followed.  This demonstration took place only sixty-five years before the mid- century we are concerned with here. 

Childhood immunizations were few at mid-twentieth century and most of us simply acquired the diseases themselves. However, the technology and science of immunization were developing rapidly and would produce successful vaccines for polio in the middle fifties and a succession of vaccines for childhood diseases in the ensuing half century.  The development of vaccines is one of the great success stories of medicine and pharmaceutical science. They virtually have eliminated the bacterial and viral infections of childhood and other infections associated with adolescence or adulthood, such as hepatitis and meningitis, among others. Vaccines eliminated smallpox from the world and we are well on the way to eliminating polio as well. Only the recurring wars in the Middle East have prevented this from happening already. The World Health Organization conducts recurring annual vaccine campaigns throughout the developing world. As a result, we slowly are gaining mastery over childhood diseases there as well. Vaccines are a triumph of public health, medicine, science, and health administration. It is beyond my understanding why some willfully ignorant people resist vaccination and thereby condemn their children to suffer diseases that could be avoided. Our world would be a very different place without vaccines.

Unfortunately, we currently are in the midst of a reaction against science and medicine brought about by the political controversies of the COVID-19 pandemic. These unnecessary, unwise, and unacceptable confrontations between medicine and politics have called into question the safety and efficacy of a new vaccine despite the efforts of the FDA to assure that any new vaccine will be both safe and effective even if brought into use as early as possible. The discussions on how to do this continue and involve the FDA, pharmaceutical companies, citizen advocates, and public health experts. Unfortunately, the unneeded and confusing political pronouncements have caused some of the general public (and some quite visible politicians) to take the position that they will not accept a COVID-19 vaccine. The ramifications of this certainly will include more resistance to the usual childhood immunizations by those already unreasonably opposed to vaccines. This will lead to the resurgence of diseases long since removed from our national conscience. Once again, we are about to suffer from self-inflicted wounds and will inflict, through our willful ignorance, wounds on our children as well.

Immunization against a disease, or acquisition of the disease itself, activates the two arms of our immune systems: the humoral (antibody) system and the cell-mediated system. The former is what we usually think about with in talking about vaccines. Neutralizing antibodies inactivate and, ultimately, bring about the death of the invading microorganisms. The cell-mediated system is concerned with the creation of a long-term cellular memory of the infection or immunization and also the production of other cells which actively seek out and kill the offending microorganisms.

When an individual acquires the same or similar infection later in life, the memory cells recognize it and activate both antibody production and the cell-mediated system. This initiates an accelerated response by both arms of the immune system against the invading microorganism and, although infection occurs, disease does not follow. A good vaccine activates both of these arms of the immune system even though they vary in their relative importance depending upon the nature of the infection. There is much discussion now in the media about coronavirus vaccines and whether or not they produce neutralizing antibody and how much antibody, and is the cell-mediated system activated as well. We will consider these vaccines next.