front 1 challenges of an HIV vaccine
why is FL, esp Miami, number 1 in HIV?
HIV-related laws | |
front 2 challenges of an HIV vaccine | back 2 - while HHS secretary, heckler repeatedly assured the american
public that thw nation's blood supply was 100% safe
- said we
must conquer AIDS before it affects the hetersexual population
and the general population. very strong public interest in
stopping AIDS before spreads outside of risk groups, before
becomes an overwhelming problem
ppl had just become aware of virus causing disease at this time
these are quotes from book - gives idea for things said at the time
hecker - secretary under regan
reluctant to safeguard blood supply |
| back 3 - immune system given head start against pathogen
- trick
immune system w/ vaccine with smth that looks like the infectious
agent -> immune sysytem thinks being infected + mount immune
response, hopefully durable to provide long-term protection
- smth administered to prevent/modify course of an infection
- usually inactive pathogen or antigen (immunogen)
-
specific against a given pathogen
|
| back 4 -
antibody based vaccine
- like for covid
- general humoral response = generate antibodies specifically
binding to virions (if virus) + neutralize it
-
cell based
- generate response so immune
cells (yellow) generate that can recognize the infected
cell
- cell is harboring particular virus / infectious
agent
- then immune cells are programmed to kill cell (and
virus contained in it)
vaccines for HIV all failed so far
currently trying a combination of these 2
several large vaccine trials in the past
- subsahara africa or asia
- RV144 - vaccine trial in
thailand, started in 2003 lasted 5 years
-
only trial where partial success was received
-
ppl had 30% less chance of becoming HIV+
|
| back 5 why was it (and still is) hard to dev vaccine?
-
HIV good
at hiding - provirus immunologically
silent
-
high intra-host mutation rate
-
most important surface protein for infecting cells is very
ingenious
1) HIV good at
hiding - provirus immunologically silent
infecting CD4+ cells easy for HIV bc have receptor + bind it well
- easy targets for HIV
- HIV does infect other cells
too (all types of cells) = other ways HIV infects cells (just not
as efficient as CD4+ cells)
- ex: nerve cell, brain cell,
etc.
up until provirus integrate into chromosome of cell = phase 2 infection
after = latent stage
- process pauses in many cells at end of phase 1
(integration into chromosome)
-
means when cell divides, it also passes on HIV genome to
daughter cell
-
cell harboring HIV provirus, its presence is COMPLETELY
undetectable by immune system
- if cell
only has provirus, it is silent and immune system cannot know
its there = provirus is immunologically silent
|
front 6 2nd reason hard to dev vaccine | back 6
2) high intra-host
mutation rate
- mutation rate makes it difficult to make vaccine
- even within 1 individual HIV+
- then antibodies
cannot effectively target HIV
- = HIV always ahead of
immune system
|
front 7
3) most important surface protein for infecting cells is very
ingenious | back 7
3) most important surface protein for infecting cells is very ingenious
- HIV envelope concealed the places for virus-neutralizing
antibodies to bind until they are needed to bind to the chemokine
receptor during fusion
-
gp120 protein on surface of HIV virion - interacts
w/ CD4 (does initial tethering)
- interaction w/ chemokine receptor also involves gp120
- best type neutralizing antibodies = those that interfere w/
interaction of gp120/chemokine receptor
- if can get
antibody to stop this from happening, HIV cannot infect the
cell
-
HIV smart bc it HIDES the part of gp120 ONLY UNTIL ITS
NEEDED
- gp120 part not showed
(occluded) normally. only exposed when ready to
bind chemokine receptor
- signal within gp120 so that
when CD4 binds, it becomes available/exposed so can bind
chemokine receptor
- = so is hard to target
- bottom line: still at least several years from
having protective HIV vaccine
|
| back 8
https://apnews.com/article/hiv-vaccine-falls-short-study-b5f556fb004e9e5590b6125d0538ee51
https://www.niaid.nih.gov/diseases-conditions/hiv-vaccine-research-history |
| back 9 - miami is worst
- ft lauderdale
- 3 new
orleans
- baton rouge
- atlanta
- orlando
- philadelphia division
- jacksn, ms
- jacksonville
fl
- memphis, tn
|
front 10 making initiative in miami | back 10 programs - some by UM
testmiami |
| back 11 - to fl statutes
- person msut know their infection status
+ that it is transmittable
- = unlawful to have sex w/
someone unless theyve been informed of the std and consent
(for normal stds)
-
hiv have longer max sentence, criminally persued whether or
not is transmitted, bigger fine, is a FELONY
|
front 12 756 ppl arrested in Florida from 1986-2017 for HIV or other STD incident
614 of those were specifically for HIV | |
front 13 READING 1 - sunshine state's darkest cloud | back 13 - 2016, highest new infection rate (47/100,000)
- miami is
epicenter
- caseload growing -> called for change
- strengthen testing + treatment efforts
- promoted PrEP
-> also using in plan to eliminate HIV transmission + AIDS
deaths
- why HIV spread so rapidly in FL
- 100 million tourists/year
- population doubled since
epidemic start in 1981
- many latins/ppl from caribbeans
immigrated, where have more prevalent HIV than the US
- 15% of HIV+ ppl in florida did not know theur status =
fuels high transmission rate
- diverse
state makes FL hard to handle HIV
- not enough ppl seek out
testing
- florida late to have needle / syringe programs
- florida slow to promote PrEP
- then florida surgeon
general mandated that all counties offer PrEP at no cost
- UM made mobile clinic
- florida's system falls
short
- not good at keeping ppl in care
- only 1/2
HIV+ ppl suppressing virus w/ ARVs
- = ppl more
likely to spread virus
-
= greater risk of developing AIDS
|
front 14 READING 2 - the mother of all challenges, Nigeria struggles to slow
the spread of HIV to babies | back 14 - nigeria - 37k of world's 160k new cases in 2016
- very
large HIV+ population in nigeria
- lack of access to ARVS
(30% coverage) = a lot of children get HIV+ from mothers
- key is to treat pregnant HIV+ women
- not enough progress
in this, though they are trying
- pregnant
woman has 15-30% chance of transmitting the virus to her baby in
utero or at birth
- standard of care = treat ALL HIV+ ppl
with ARV combination therapy
- newborns should receive ARVs
for 6 weeks after birth
- formal fees in clinics also deter
women from getting care
- corruption is factor - informal
fees (scams) are a part of the problem. There has been systematic
embezzlement by ministry of health staff + improper auditing
- in a church, had celebration called baby shower + baby reception
- expecting women attend baby showers where get blood drawn
to test for things, including HIV
- if newborns, attend
baby reception - also get gift bags + check on ppl who were HIV+
at an earlier service (like baby shower) to see if they are
following their treatment, etc.
-
these celebrations are part of the healthy beginning
initiative funded by US NIH
- expanded to more
churches
- takes advantage of the fact that 90% nigerians
regularly attend church/mosque
- also good bc religious
leaders dont carry burden of politicians. ppl believe + follow
them
- HIV testing in pregnant women in churches inc from
55% to 92%
|