As the world is
starting to undertake an unprecedented vaccination effort to control the
current pandemic, it might be useful to look at other historic vaccination
programs.
Smallpox
Attempts at
smallpox vaccination have gone on for many centuries using material from the smallpox
pustules of people with mild cases or from cowpox pustules to inoculate healthy
persons. The most widely recorded example occurred in 1768 when Catherine the
Great, Empress of Russia, allowed a Scottish physician to inoculate (vaccinate)
her. She developed a mild case, recovered after two weeks, and then had fluid
from her own pustules used to inoculate her son and members of her court. After
Catherine’s heroic action, inoculation became quickly accepted, and by 1780 two
million inoculations were administered in the Russian Empire. An alternative
and improved method of vaccination was introduced in 1796 by Edward Jenner, who
noted that milkmaids who had been infected with cowpox, a skin infection caused
by a virus related to the smallpox virus, did not get smallpox. He removed
fluid from the cowpox pustules of a young dairymaid and inoculated an eight-year
old boy. The child developed a mild fever but recovered – a successful but
highly unethical experiment.
During the 20th
century, smallpox was responsible for 300 to 500 million deaths, and it is
estimated that in the early 1950s, 30 to 50 million cases occurred in the world
each year. Of those infected, three out of every 10 died and others were left
terribly scarred. From 1966 to 1977 the World Health Organization (WHO)
undertook a successful global smallpox eradication program under the direction
of Dr. Donald A. Henderson. The last known case of smallpox in the world
occurred in Somalia in 1977, and by 1980 the WHO declared that smallpox had
been eradicated. It is the only human virus infection to achieve this status
and is considered one of the crowning achievements of public health. Dr.
Henderson went on to become Dean of the Johns Hopkins Bloomberg School of
Public Health.
The last smallpox
scare in the United States occurred in 1947 with a case imported from Mexico.
It spread to the patient’s wife and 10 other contacts and resulted in two
deaths. The New York City Department of Health under its director, Dr. Israel
Weinstein, quickly mobilized forces with a “Be Sure, Be Safe, Be Vaccinated”
campaign, starting off with Dr. Weinstein being vaccinated in front of news
cameras. President Harry Truman also got into the act and rolled up his sleeve.
It was a time when there was tremendous faith in the medical community. In the
first two weeks, five million New Yorkers were vaccinated (a feat hard to
duplicate today), and within a month, 6,350,000 were vaccinated in New York
City. In the 1960s, studies carried out at the Centers for Disease Control and
Prevention (CDC) documented the frequency of complications from the smallpox
vaccine and concluded that the risk of the vaccine exceeded the risk of
importing smallpox cases into the U.S. Routine smallpox vaccination was thus
stopped in the U.S. in 1972.
Smallpox is still
the only human virus infection to have been eradicated on a worldwide basis.
One animal virus infection, Rinderpest (cattle plague), has been eradicated. A
lethal infection of cattle, it was possibly the cause of cattle dying in Egypt
during the time of the Ten Plagues. Rinderpest was considered eradicated
worldwide in 2011.
Poliomyelitis
Eradication of
polio from the U.S. represents another great public health triumph. In the
early half of the 20th century, polio outbreaks occurred frequently in
the U.S. during the summer months, leading to paralysis in one to two percent
of cases, most notably Franklin Delano Roosevelt. In 1952, the country’s worst
single year, there were 58,000 reported new cases in the U.S. resulting in
21,000 paralytic cases and over 3,000 deaths. In the U.S. it was the most
feared disease in the 20th century. Some of us probably have
recollections of swimming pools being closed, pictures of people in iron lungs,
and the March of Dimes campaign popularized by President Roosevelt.
By 1909 it was
determined that polio was probably caused by a virus, and attempts at
developing a vaccine went on throughout the first half of the 20th
century but without success. However, there were several key research findings
that paved the way to a vaccine. In 1949, David Bodian, a researcher at Johns
Hopkins identified the three different strains of the poliovirus, and in that
same year, John Enders and colleagues at the Boston Children’s Hospital were
able to grow the poliovirus in tissue culture, work for which they later
received the Nobel Prize.
A dramatic
breakthrough came in 1953 when Dr. Jonas Salk, a researcher at the University
of Pittsburgh, announced that he had successfully tested an injectable vaccine
against polio using a killed (inactivated) form of the virus. The vaccine was
approved in 1955 but was not widely available until 1957. That year, polio
cases in the U.S. decreased to 6,000. Subsequently, an oral vaccine using a
live attenuated (weakened) strain of the virus was developed by Dr. Albert
Sabin at the University of Cincinnati and approved for use in 1961. For several
decades, there was a fierce rivalry between Drs. Salk and Sabin over which
vaccine should be used. Because of rare but serious vaccine-related
complications, the use of the Sabin vaccine was discontinued in the U.S. in
1999. However, because of lower cost and ease of administration (drops on a
sugar cube), the Sabin vaccine continues in use throughout most of the world.
Today, polio has been eradicated from the U.S., and worldwide polio cases have
decreased from a yearly average of 350,000 to only 99 reported cases in 2017.
There are still sporadic cases in under-resourced countries, particularly
Pakistan and Afghanistan, where vaccination efforts are hindered by distrust of
vaccines and ongoing political conflicts.
Progress with Other Vaccines
Currently, the WHO
lists 26 diseases for which a vaccine is available. COVID-19 vaccines will need
to be added to the list. In the U.S., 16 vaccines are recommended for routine
use from birth to 19 years, and a number of vaccines, including those for
diphtheria, tetanus, pertussis, influenza, pneumococcal disease (pneumonia),
and shingles are recommended for adults. Medicare and, under the Affordable
Care Act, most insurance companies are required to cover the cost of
recommended vaccinations. Also, there is a Federal Vaccines for Children
Program that pays for vaccinations of children under age 19 years who are
Medicaid-eligible, uninsured, under-insured, Native Americans, or Alaska
natives. The CDC website is an important resource of vaccine information,
including those needed for people with special health conditions and for
international travel. Major diseases with unmet vaccine needs include AIDS and
malaria. There is a licensed but not highly effective vaccine for malaria,
while the search for a vaccine against AIDS has been going on for 40 years without success.
The rapid pace at
which COVID-19 vaccines have been developed is remarkable. Vaccine development
usually takes 10 to 15 years, but in the case of COVID-19, this was shortened
to 12 months – from the isolation and genetic sequencing of the virus in
December 2019 to approval of two vaccines in the U.S. in December 2020, with
anticipation of additional approvals in 2021. Much of this is due to advances
in mRNA vaccine platform technology over the past two decades, which should
lead to faster vaccine development going forward, hopefully including one for
HIV.
It is also well
documented that vaccines provide not only a health benefit but also a
tremendous economic return. It is estimated that for every one dollar spent on
childhood vaccinations in the U.S. there is a cost saving of $10.90, with even
greater economic benefit in low- and middle-income countries. The CDC
calculates that the vaccination of children born between 1994 and 2018 has
saved the U.S. nearly 406 billion dollars in direct medical costs and 1.88
trillion dollars in total societal costs. The good news with the COVID-19
vaccines is that because of governmental support for the development and
purchase of the vaccines, there will be no charge regardless of one’s insurance
status.
