human settlements/communities increased the possibility of a disease infecting many people at a time in a geographical area i.e known as an epidemic. And with time as communities mingled with each other either for trade, war, etc. they spread the diseases to new location fueling the pandemic.

1. Top 10 Deadly Diseases With Urgent Need of
Vaccinations
Presented By:
Dr. Shikha Thakur

2. Ever since organisms developed the complex interactions among them lead to the existence
of diseases. Evolution of human and diseases has been going on simultaneously. Mainly the
evolution of diseases has been linked to a shift in the way of life from hunter-gather to
agrarian. Many diseases like bubonic plague, smallpox, influenza, malaria, leprosy,
tuberculosis, and others first appeared during this period. This type of human
settlements/communities increased the possibility of a disease infecting many people at a
time in a geographical area i.e known as an epidemic. And with time as communities
mingled with each other either for trade, war, etc. they spread the diseases to new location
fueling the pandemic.

3. With the constant progress in human civilization, people started to devise techniques to cure or evade
diseases. This beckoned the dawn of medical science and technology and lead to
pioneering discoveries and inventions. We have developed many effective treatments like antibiotics,
vaccines to name some, but still, we haven’t completely come out of the grip of diseases. Still, there are
many instances of new or re-emerging outbreaks in the current world regardless of the advancement,
taking a grave toll on the human population as well as challenging the medical practices and research.

4. Epidemic vs Pandemic
• Throughout the history of mankind, we find many instances of deadly
diseases which are termed as epidemics or pandemics. Though there is a
debate for these two terms about their appropriate usage, officially when an
epidemic crosses the country’s boundary across continents it is declared to
be a pandemic.

5. • The earliest recorded pandemic can be traced back to the Peloponnesian
War. The plague which spread across countries and continents from Libya,
Ethiopia, and Egypt to Athens. The plague had the symptoms of fever, skin
lesions, bloody throat, and tongue, etc. which killed almost two-thirds of the
population. It is was the major reason behind the defeat of the Athenians in
the war.

6. Of recent, we had many outbreaks of severe nature. One being the Ebola virus
outbreak in West Africa. Ebola virus disease (EVD) is a rare hemorrhagic and deadly
fever, which affects human and non-human primates. It spreads via direct contact with
an infected animal or a sick or dead person infected with the Ebola virus. As it is still
restricted to western Africa so still considered an epidemic.

7. • Another such outbreak is of insidious Zika pandemic which had spread across more
than 80 countries or geographic territories. Zika virus, initially thought as
inconsequential as it was only confined to some African/ Asian countries but in
recent years it had been spread across the world acquiring the status of the
pandemic because of the vector – ubiquitous mosquito Aedes aegypti. The most
dangerous feature of the disease is the unprecedented ability to harm the unborn
child. Though these are some examples there are any more instances of epidemic
and pandemic occurring in the world. For all such recent outbreaks, a lot of
research is going on in treatment, disease management, and prevention in the form
of vaccine development.

8. Vaccines
The concept of a vaccine has been existing for a long time, but a significant and distinguished
experiment by Edward Jenner helped to establish the concept. His work involved inoculation of
a 13-year-old boy with vaccinia virus which successfully imparted resistance against smallpox.
With this successful immunization process, many researchers including Louis Pasteur, Alexander
Glenny, etc. contributed to further develop the field vaccinology.

9. Basically, any biological immunogenic preparation with the ability to impart immunologic
resistance against disease is a vaccine. Vaccine preparation can range from a weakened or
killed microbe to an isolated toxin or surface protein and carbohydrate. Recent
developments in RDT have been utilized to create recombinant vaccines and recombinant
vector vaccines. Another latest development is multisubunit vaccine and DNA vaccine is in
pipeline. A vaccine is a mimic of the pathogen which can stimulate the immune system but
should not cause the diseases.

10. Vaccine Preventable Diseases
According to the World Health Organization (WHO), active immunization by
vaccination saves the lives of 2.5 million people on a yearly basis. The best instance
could be of smallpox, a deadly and disfiguring disease caused by the Variola virus
which has ravaged the human population for thousands of years. By undertaking an
active immunization mission conducted throughout the world it was finally
eradicated in 1980 with no more naturally occurring cases so far.

11. • Similarly, Polio has been almost eradicated from the world except for few
locations. A staggering number of children at approximately 18 million have
been successfully saved from paralysis by the efforts of Global Polio
Eradication Initiative’s (GPEI) since 1988. Moreover, vaccination can also
reduce the medical cost worldwide which is a serious burden mainly for
developing and underdeveloped countries.

12. • Of late there is an emergence of vaccine hesitancy among people, which is
of serious concern and has been listed as one of the top 10 global health
threats by WHO in 2019. As a consequence, many vaccine-preventable
diseases are on rising globally. The incidences of measles and diphtheria have
gone up by 30% worldwide. In North America alone more than 71,550 cases
of whooping cough have been diagnosed over a nine-year span since 2008,
along with 15,000 cases of mumps. Similarly, about 670 measles outbreaks
were reported in the US in 2014, even after when it was declared eradicated
by CDC in the year 2000.

13. • Reasons behind these outbreaks are listed as a refusal to vaccination, under-
vaccination, global travel, and less effective vaccines. It is very important to
support the immunization program to stop these outbreaks or else they can
be a cause of the epidemic/pandemic. Some of the vaccine-preventable
diseases which require urgent immunization have been discussed in detail
further. Apart from the recent outbreaks of Zika, Ebola, Candia Aurius –
there are many commonly occurring Diseases with Urgent Need of
Vaccinations.

14. Listed below are Top 10 Deadly Diseases With
Urgent Need of Vaccinations:
• 1. Measles
• Measles is one of the deadly and highly contagious vaccine-preventable diseases
which affects young children globally. According to WHO approx. 2.6 million
unimmunized people die of measles yearly. It is caused by the rubeola virus and so
far, many strains of the virus have been identified. Transmission is airborne and
occurs from an infected person via droplets from the nose, mouth or throat. The
infection has an incubation time of 10-12 days after which initial symptoms appear.

15. • Symptoms include a high fever with bloodshot eyes, runny nose, and appearance of
tiny white spots on the inside mouth. A rash develops several days later first on the
face and upper neck which gradually spreads downwards. Usually, this condition
subsides without treatment in next 7 to 10 days and generates a lifelong immunity.
Severe complications can occur in malnourished children, especially those with a
weak immune system. Under such conditions, it can lead to blindness, encephalitis,
severe diarrhea and dehydration, and severe respiratory infections such as
pneumonia.
• Vaccine available is either alone, or in a measles-rubella (MR), measles-mumps-
rubella (MMR), or measles-mumps-rubella-varicella (MMRV) combination.

16. 2. Whooping cough (Pertussis)
• Pertussis is a contagious bacterial disease caused by Bordetella pertussis. It
infects the respiratory tract mainly nose, mouth, and throat. Transmission is
airborne through aerosols produced by coughing or sneezing. The incubation
period is 7-10 days and symptoms include mild fever, runny nose, and cough.
The cough gradually worsens into paroxysmal cough lasting up to four to
eight weeks. The paroxysms may be followed by periods of apnoea in
youngest infants and generally whooping. Based on this another name for
pertussis is whooping cough. Some cases it may lead to complications like
encephalitis and pneumonia. This condition can be prevented by vaccination.

17. 3. Mumps
• Another viral infection that can affect both children and adults is mumps. A highly
contagious disease that can spread from an infected person to others through
airborne droplets. The site of infection is salivary- parotid glands and thus also
called infectious parotitis. Symptoms are generally non-specific fever, headache, and
malaise along with swelling of parotid glands. Predominantly infecting children aged
between five and nine years but can also occur in adults. In adults, the condition is
serious and have many complications like meningitis, orchitis, deafness, encephalitis
and permanent neurological damage. The disease is preventable by immunization
with combined measles-mumps-rubella (MMR) vaccine.

18. 4. Rubella
• Like measles, Rubella is an acute, mild viral disease caused by the Rubella virus.
Generally, affects children and young adults and transmitted through airborne
droplets. Symptoms appear after 2-3 weeks of exposure to the virus and last up to 5
days. A characteristics red rash appears on the face and then spreads to other parts
of the body. Patients also suffer from mild fever, headache, joint ache, runny nose,
and enlarged lymph nodes. In case infection occurs just before conception and in
early pregnancy it may lead to miscarriage, fetal death or congenital rubella
syndrome (CRS). A safe and effective vaccine is available for Rubella either as
monovalent or combination preparations in form of measles (MR), measles and
mumps (MMR), or measles, mumps and varicella (MMRV).

19. 5. Diphtheria
• Diphtheria a respiratory tract infection caused by bacteria, Corynebacterium diphtheria. In 5
– 10% of cases it is fatal mainly in young children. The bacteria mainly colonize the throat
and nasopharyngeal tract but can affect other organs by releasing exotoxins. The disease is
contagious and can spread through direct contact and aerosols from an infected person.
• Diphtheria patients show acute symptoms of low fever, sore throat, and swollen glands
along with characteristics buildup of a tough membrane of made up of dead cells in the
respiratory tract which can lead to suffocation and difficulty in swallowing. In severe
conditions, the toxins can damage myocardial cells and nerves causing myocarditis and
peripheral neuropathy.
• Diphtheria vaccine is available against the toxins as toxoids either alone or in combination as
DTwP/DTaP vaccine.

20. 6. Influenza
• Influenza is an acute respiratory disease caused by influenza viruses which can be fatal.
Influenza viruses are of different subtypes among that A or B is mainly responsible for
infection in human. Highly contagious through contact or aerosol and shows seasonal
epidemics with endemic regional circulation. The incubation period is 2-4 days and causes
mild to severe infection with symptoms ranging from fever, headache, sore throat, runny nose
and cough to malaise. In severe illness, any underlying disease can worsen or even make a
person susceptible to secondary bacterial infection. People at high risk for such complications
include young children, pregnant women, elderly and people with chronic health conditions.
This is one of the commonly occurring diseases since ages with an urgent Need of better
vaccinations. Recent pandemic occurred in the year 2009 by H1N1. Though it is preventable
by immunization by flu shots, yet the continuously evolving virus requires updated vaccines.
Recent pandemic occurred in the year 2009 by H1N1. Though it is preventable by
immunization by flu shots, yet the continuously evolving virus requires updated vaccines.

21. 7. Meningitis
• Meningococcal meningitis is an endemic global disease, caused by bacteria
Neisseria meningitides. Out of 12 serotypes, A, B, C, X, W, and Y are mainly
responsible for the disease. Their distribution is found to vary based on
geographical region and time. In this disease, the meninges (protective
membranes) that surround the brain and spinal cord get infected. Commonly
occurring in babies, children, teenagers, and young adults. If not treated leads
to septicemia and has high fatality of more than 50%. Transmitted from
direct physical contact, or through airborne aerosols.

22. • Symptoms include high fever, fits, stiff neck, headache, drowsiness,
unresponsiveness and in some cases rashes. In severe conditions, even after
recovery, long term problems may be persisting like hearing loss, epilepsy
and even loss of limb.
• Vaccination against the pathogen offers some protection. Vaccine mostly
available is polysaccharide and conjugate vaccines in bivalent (A, C), trivalent
(A, C, W135), and quadrivalent (A, C, W135, Y) formulations. Some also
come with additional protection against Haemophilus influenza type b.

23. 8. Hepatitis
• Hepatitis is inflammation and damage of the liver caused by a viral infection.
Classified as Hepatitis A, B, and C depending on the causative virus. All-cause acute
infection, but mostly B and C lead to chronic infection.
• Hepatitis A infection causes mild to severe illness. Most patients make full recovery
but in cases of severe illness, complications can arise leading to acute liver failure
and high mortality. Transmitted primarily via the fecal/oral route or direct contact.
Improved sanitation and immunization are effective preventive measures. Hepatitis
B infection is a serious liver disease responsible for the death of 780,000 people
yearly due to liver cirrhosis and liver cancer. Transmission occurs via direct contact
with the blood or other body fluids of an infected person. It is preventable with
currently available safe and effective vaccines.

24. 9. Tetanus
• Tetanus also is known as lockjaw, is a fatal bacterial disease, caused by ubiquitous Clostridium
tetanus mainly through exposure to spores. Being ubiquitous it is difficult to eradicate as spores
can be found anywhere, soil, surgical instruments, etc. It is a non-contagious disease and enters
the body via deep wounds. The bacteria have an incubation period of 10 days and after that
starts to release neurotoxins which impair the nervous system.
• Common symptoms are fever, elevated blood pressure, muscle spasms – jaw muscles, stiffness
in the neck and abdominal muscles. It can also stop normal breathing and lead to mortality. It
can occur to anyone but is serious mainly for pregnant mothers and neonates. According to
WHO, in 2017 about 30,848 newborns died due to neonatal tetanus.
• There is no cure for the disease but can be prevented by active immunization. Most of the
vaccines are toxoid based and often come in combination with diphtheria toxoid.

25. 10. Varicella
• Another highly contagious disease is Chickenpox or Varicella which occur
worldwide. It is caused by Varicella-zoster virus and is transmissible via droplets or
direct physical contact. The virus has an incubation period of 10-21 days and can
range from mild to severe. Most of the cases symptoms include fever, malaise, and
rashes which self-limits and subsides by 7-10 days. Some cases severe complications
can arise like secondary bacterial infections, encephalitis and can prove fatal. People
at risk of high morbidity and mortality are infants and immunocompromised
individuals. It can be prevented by immunization with live attenuated vaccines either
available as a single antigen and in combination with measles, mumps and rubella
vaccine.

26. • Recent outbreaks of many vaccine-preventable diseases have set off the
alarm throughout the world about the current status of immunization. With
the reduction in occurrences of many epidemics/pandemics, people have
forgotten the intensity of damage caused by them. Their elimination has
been possible only through active immunization programs. The current trend
of lack of trust over vaccines, vaccine hesitation, and under-vaccination is a
serious issue which needs to be resolved asap. Otherwise, humanity should
prepare to relive the horrible past of pandemics and epidemics whose threat
is looming large.

27. THANK YOU