Notes for Life science students Use it wisely Enhance your knowledge

1. DEVELOPMENT OF VACCINE AGAINST
HIV, MALARIA AND TUBERCULOSIS

2. HIV
HIV (human immunodeficiency
virus) is a virus that attacks the
body’s immune system. If HIV is
not treated, it can lead to AIDS
(acquired immunodeficiency
syndrome). There is currently no
effective cure. Once people get
HIV, they have it for life. But with
proper medical care, HIV can be
controlled.

3. Cause
HIV is caused by a virus. It can spread through sexual contact, illicit
injection drug use or sharing needles, contact with infected blood, or
from mother to child during pregnancy, childbirth or breastfeeding.
HIV destroys CD4 T cells — white blood cells that play a large role in
helping your body fight disease

4. Symptoms
• The first signs of HIV infection may be flu-like symptoms:
• Fever
• Chills
• Rash
• Night sweats (heavy sweating during sleep)
• Muscle aches
• Sore throat
• Fatigue
• Swollen lymph nodes
• Mouth ulcers
• These symptoms may come and go within two to four weeks. This stage is calle
acute HIV infection.

5. Molecular Basis of
Vaccine
Efficacy/Response Relevant Information
AIDSVAX B/E
No efficacy Bivalent subunit vaccine, 2 Gp120
from clades B and E were combined
and alum adjuvant added
AIDSVAX B/B
No efficacy Bivalent subunit vaccine, 2 Gp120
from clade B were combined and
alum adjuvant added
ALVAC-HIV and AIDSVAX B/E
31.2% efficacy against HIV-1
acquisition
NA
MRKAd5 HIV-1 gag/pol/nefB
No efficacy Both studies prematurely terminated.
People with high titer to adenovirus
were more likely to contract HIV.

6. Treatment
• There is no cure for HIV infection, but it can be
treated with medicines. This is called
antiretroviral therapy (ART). ART can make HIV
infection a manageable chronic condition. It also
reduces the risk of spreading the virus to others.
• Most people with HIV live long and healthy lives
if they get ART as soon as possible and stay on it.
It’s also important to take care of yourself.
Making sure that you have the support you need,
living a healthy lifestyle, and getting regular
medical care can help you enjoy a better quality
of life.

7. MALARIA 🦟
• Malaria is a life-threatening disease. It’s
typically transmitted through the bite of
an infected Anopheles mosquito. Infected
mosquitoes carry the Plasmodium
parasite. When this mosquito bites you,
the parasite is released into your
bloodstream.
• Once the parasites are inside your body,
they travel to the liver, where they
mature. After several days, the mature
parasites enter the bloodstream and
begin to infect red blood cells.

9. Malaria 🦟
• Malaria is a disease caused by a
parasite. The parasite is spread to
humans through the bites of infected
mosquitoes. People who have malaria
usually feel very sick with a high fever
and shaking chills.
• While the disease is uncommon in
temperate climates, malaria is still
common in tropical and subtropical
countries. Each year nearly 290 million
people are infected with malaria, and
more than 400,000 people die of the
disease.

10. Symptoms
Fever
Chills
General feeling of discomfort
Headache
Nausea and vomiting
Diarrhea
Abdominal pain
Muscle or joint pain
Fatigue
Rapid breathing
Rapid heart rate
Cough

11. Causes
• Malaria is caused by a single –celled parasite of the genus
plasmodium the parasite is transmitted to humans most
commonly through mosquito bites
• Malaria can occur if a mosquito infected with the
Plasmodium parasite bites you. There are four kinds of
malaria parasites that can infect humans: Plasmodium
vivax, P. Ovale, P. Malariae, and P. Falciparum.
• P. Falciparum causes a more severe form of the disease and
those who contract this form of malaria have a higher risk of
death. An infected mother can also pass the disease to her
baby at birth. This is known as congenital malaria.
• Malaria is transmitted by blood, so it can also be
transmitted through:
• an organ transplant
• a transfusion
• use of shared needles or syringes

12. Malaria vaccine
• The RTS,S/AS01 vaccine and the PfSPZ
vaccine products are two of the most
promising malaria vaccine candidates to
date. Another pre-erythrocytic vaccine
candidate, R21, recently showed good
efficacy in an early trial testing it among
children 5 – 17 months of age
• There’s a vaccine for children which was
developed and tested in Ghana, Kenya
and Malawi in a pilot program. The RTS,
S/AS01 vaccine is effective against
Plasmodium falciparum malaria, which
causes severe disease in children.
• Other programs are working to develop a
malaria vaccine.

13. • Vaccination with RTS,S induces antibodies against
circumsporozoite protein (CSP), which is expressed by
sporozoites, the infective form of Plasmodium that
mosquitos transmit. During infection in unvaccinated
individuals, sporozoites travel to the liver, where they
move through hepatocytes and differentiate to
hepatic merozoites. CSP is expressed in the early liver
stages, but not by liver stage merozoites. Antibodies
to CSP following RTS,S vaccination immobilize the
sporozoites, thereby preventing infection of
hepatocytes. RTS,S-induced protection from infection
and severe disease wanes over time and correlates
with the level of anti-CSP antibodies. RTS,S-induced
immune responses do not interfere with the
infectivity of Plasmodium gametocytes to mosquitoes.
Even following vaccination, most children will carry
parasites that will infect mosquitoes; thus,
transmission in the population will remain unchanged

14. Tuberculosis

15. Tuberculosis
• Tuberculosis is an infectious disease that can cause infection in your lungs or other
tissues. It commonly affects your lungs, but it can also affect other organs like your
spine, brain or kidneys. The word “tuberculosis” comes from a Latin word for
“nodule” or something that sticks out.
• Tuberculosis is also known as TB. Not everyone who becomes infected with TB gets
sick, but if you do get sick you need to be treated.
• If you’re infected with the bacterium, but don’t have symptoms, you have inactive
tuberculosis or latent tuberculosis infection (also called latent TB). It may seem like TB
has gone away, but it’s dormant (sleeping) inside your body.
• If you’re infected, develop symptoms and are contagious, you have active tuberculosis
or tuberculosis disease (TB disease)
The three stages of TB are:
*Primary infection.
* Latent TB infection.
*Active TB disease.

16. Causes
• Tuberculosis is caused by a bacterium called
Mycobacterium tuberculosis.
• People with active TB disease in the lungs or voice
box can spread the disease. They release tiny
droplets that carry the bacteria through the air.
This can happen when they’re speaking, singing,
laughing, coughing or sneezing. A person can get
an infection after inhaling the droplets.
• The disease is more likely to spread when people
spend a lot of time together in an indoor space.
So the disease spreads easily in places where
people live or work together for long periods.
Also, the disease spreads more easily in crowded
gatherings.
• A person with a latent TB infection cannot pass
the disease to other people. A person taking
drugs to treat active TB disease usually can’t pass
the disease after 2 to 3 weeks of treatment.

17. Treatment
• Bacillus Calmette-Guerin (BCG) is the live
attenuated vaccine form of Mycobacterium bovis
used to prevent tuberculosis and other
mycobacterial infections. The vaccine was
developed by Calmette and Guerin and was first
administered to human beings in 1921. BCG is the
only vaccine against tuberculosis. It is the most
widely administered vaccine and usually a part of
the routine newborn immunization schedule. BCG
vaccine also offers protection against non-
tuberculous mycobacterial infections like leprosy
and Buruli ulcer. This activity reviews the mode of
action of the BCG vaccine and highlights the role of
the interprofessional team in educating patients
about tuberculosis prevention.

18. Vaccination
In countries where tuberculosis is common, infants
often are vaccinated with the bacille Calmette-
Guerin (BCG) vaccine. This protects infants and
toddlers who are more likely to have active TB
disease in the fluid surrounding the brain and
spinal cord.
The vaccine may not protect against disease in the
lungs, which is more likely in the United States.
Dozens of new TB vaccines are in various stages of
development and testing.