Tdap Efficacy Wanes Rapidly
A recently published study analyzed the efficacy of
the Tdap vaccine in preventing pertussis in adolescents. In the US,
acellular pertussis vaccines replaced whole-cell vaccines for the 5-dose
childhood vaccination series in 1997. A sixth dose of pertussis-containing
vaccine – Tetanus toxoid, reduced diphtheria toxoid, and acellular
pertussis, adsorbed (Tdap) – was recommended in 2005 for adolescents and
adults. Despite high Tdap vaccine coverage among adolescents, California
experienced a large pertussis outbreaks in 2010 and 2014. Researchers
examined these outbreaks, and on the basis of 1207 reported cases of
pertussis, they found that Tdap vaccine provided moderate defense
against the illness during the first year after vaccination but not much
longer. Immunity waned during the second year, and little protection
remained 2 to 3 years after vaccination. Tdap vaccine effectiveness
during the first year after vaccination was 68.8%, decreasing to 8.9% by
4 years after
vaccination. During each year of outbreak, incidence dropped off
precipitously among the age groups composed of children who would have
received the whole-cell pertussis vaccine. Presumably vaccination in
childhood by the whole cell vaccine provided long lasting immunity to
persons in contrast to the acellular vaccine. (Pediatrics March 2016)
The Case for Euthanasia
The case of Aruna Shaunbag, the nurse who lay in a
vegetative state in a Mumbai hospital between 1973 and 2015, had thrown
up many questions to the medical and legal communities as well as
society as a whole. In 2011, the Supreme Court had made a landmark
judement widely appreciated for its nuanced handling of this complex
issue. It provided clear guidelines on the following questions: When can
a person be declared brain dead or a persistent vegetative state? What
are the rights of this person? What are the responsibilities of the care
providers?
The Union Government has now formed a Constitutional
bench of the Supreme Court which is examining a draft bill proposed by
the Law ministry. It is developing a legislative framework to answer
whether patients who are terminally ill and beyond the scope of medical
revival can be allowed to die with dignity. It is also examining whether
living wills could be allowed. Living wills are authorizations made by
persons in a healthy state saying they need not be put on life support
systems in the event of their going into a persistent vegetative state
or terminal illness.
The experts have not agreed on active euthanasia
because of the obvious possibilities of misuse. But it supports passive
euthanasia or withdrawal of life support subject to safe guards and fair
procedure. (The Hindu 2 February 2016)
Smoke-free Movies
The WHO has called upon governments to rate movies
based on their inclusion of scenes portraying smoking. It is quite clear
that after the tight restrictions on advertisements, movies now remain
one of the few widespread mechanisms by which children and teenagers are
lured into smoking. In the United States, studies have shown that 37% of
new adolescent smokers have been influenced due to cinema. In 2014, 44%
of all Hollywood movies and 36% of movies rated for children portrayed
smoking. The US Surgeon general declared that adult rating of films with
smoking scenes would reduce adolescent smokers by one-fifth and prevent
one million tobacco-related deaths in children and teenagers. The WHO
smoke-free movie report has also recommended that movies with tobacco
imagery may be made exempt from public subsidies.
(http://www.who.int/mediacentre/news/releases/2016/protect-children-from-tobacco/en/)
Zika Virus Vaccine From India
Bharat Biotech has created history of sorts by becoming the first
company to file a global patent for two candidate vaccines against the
Zika virus. Eighteen months ago, a group of researchers from Bharat
Biotech started work to develop a traveler’s vaccine against three
mosquito borne viruses – Chikungunya, Japanese Encephalitis and Zika. In
July 2015, they had developed two vaccines against the Zika virus – a
recombinant vaccine and an inactivated vaccine. The ‘Zikavac’ is ready
for preclinical trials as is their Chikungunya vaccine. It is expected
that women will be the first beneficiaries of a successful Zika vaccine,
followed by adults because of the purported risk of Gullain Barre
Syndrome in adults due to the Zika virus. (The Hindu 4 February 2016).