Diseases With Urgent Need of Vaccinations – Top 10 List
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.
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 reemerging 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.
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.
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.
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.
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.
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 of vaccinology.
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.
The mechanism behind the vaccine is the activation of adaptive immunity to generate memory cells, which can immediately stop the pathogen in case of infection by triggering memory response. Memory response is very intense and rapid immune response in form antibody production and activation cell-mediated immunity, which eliminates the infection/pathogen from the body before it can cause disease.
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. 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.
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.
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.
Listed below are Top 10 Deadly Diseases With Urgent Need of Vaccinations:
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.