the discovery of the plague pathogen Yersinia pestis which exemplifies the need of a

global perspective for vaccine distribution.

The development of vaccines reached its golden age during the twentieth century

with the implementation and widespread use of many successful vaccines. As a

result, smallpox has been eradicated (WHO declaration of global eradication by

October 1979) and many other infectious diseases that have threatened humanity for

centuries have virtually disappeared [7].

Eradication of the polio virus infection was targeted by year 2000 through the

WHO Global Eradication Initiative [8]; however, cases persist in war areas not

accessible to vaccination.

Accumulated data since 1800 shows a decrease of the global child mortality

under the age of 5 years from 43% (1800) to 4.3% (2015) [9]. The decrease of

global child mortality has been largely attributed to vaccination. The World Bank

estimated that a combination of vaccines, malaria prevention, and improved new-

born health care has helped reduce under-5 child mortality globally from 20 million

in 1960 to 6.6 million in 2012. Consequently, the Bill and Melinda Gates

Foundation is building its strategy to deliver vaccines to low-income countries to

achieve in 2035 the goal of reducing the deaths by 1,000 births to 15, a ratio

achieved in the United States in 1980.

Overall, these contributions to humanity are major and vaccines are making a

great difference in human health, yet they are taken for granted by the public until

challenged by a pandemic situation, as illustrated by the current COVID-19 pan-

demic situation and global exceptional measures implemented.

Table 1.1 shows the vaccines for preventable diseases since their first in-

troduction in the United States in 1798, starting with smallpox. Within the list of

vaccines shown here, in white background are microbial types of infections for

which vaccine production use microbial fermentations.

Among the vaccines listed, some are for travelers in specific countries where the

infectious disease is endemic. For example, yellow fever vaccination is mandatory

when traveling to countries in Western Africa where there is a risk of infection. The

number of marketed vaccines is increasing, but compared to pharmaceutical drugs,

this number remains low.

1.2

ROLE OF PUBLIC HEALTH ORGANIZATIONS AND INDUSTRY

Vaccines are considered commodities and they fall under public health priorities.

Governments are engaged globally aiming to implement solutions to address

public health emergencies in their countries and globally in cases of pandemic

situations. The COVID-19 unfolding pandemic situation since January 2020

is a live demonstration of the needs of these precious commodities to control

the global public health situation and reduce the emergence of SARS-CoV-2

variants.

Because of its public health importance, historically, vaccine manufacturing

and delivery was managed by public health organizations such as the National

Institute of Allergy and Infectious Diseases in the United States; Connaught

2

Bioprocessing of Viral Vaccines