The dengue vaccine is about to celebrate one year since its approval in Argentina and the National Immunization Commission (CoNaIn)
has not yet defined
what will be the strategy for using this tool against the disease that is growing the most in the country: It is expected that 2023-24 will be
the worst season in history
, a status provisionally held by the previous year.
While the scientists who advise the Government debate the issue (and two northern provinces have already decided to start vaccinating on their own in areas of high impact of dengue),
an overlapping discussion
seems to have taken place between the arguments used by the Government and those highlighted by the manufacturer of the new medicine, the Takeda laboratory.
Despite the high levels of dengue circulation (with a record number of cases and deaths for this time of year), the national Executive came out to confirm this Thursday that the vaccine will
not be used as a health strategy
for the moment .
While this is happening, a former advisor to the World Health Organization (WHO) who a decade ago was a health official in the province of Córdoba and today works in Spain, warned that “it is not a question of vaccine
yes or vaccine no.”
", but of "a concrete and comprehensive policy to counteract dengue."
The Ministry of Health was encouraged to now officially communicate what they only said in draft until a few days ago.
Mario Russo, head of the area, stated: “After multiple reviews with scientific societies and references from academic sectors of infectology, we conclude that in an outbreak context like the current one, the vaccine
is not recommended
as a public health strategy to prevent the spread. of the disease, because it requires two doses, with an
interval of three months
to achieve adequate protection for the population."
An image of the Aedes aegypti, a dengue-transmitting mosquito.
Photo: EFE
The argument, in these terms, would not be definitive, but would in principle establish
a parenthesis until the next
dengue season, at which time it is expected that there will be more information on the effectiveness of the drug and, furthermore, if used, it can be take advantage of coverage that generates immunity
before
cases skyrocket.
The newsletter that quotes Russo bears the letterhead of the Pan American Health Organization (PAHO), which in turn links to another statement from the organization with considerations about the vaccine: “It demonstrated its
effectiveness
in endemic countries to prevent the
symptomatic disease
of dengue (confirmed virologically) and hospitalization in children aged 4 to 16 years who are seropositive (with infection before vaccination) against
the four serotypes
of the virus.
Then it raises some limitations right there: “The vaccine did not demonstrate adequate efficacy in seronegative children against symptomatic dengue disease, hospitalization, dengue hemorrhagic fever, or severe dengue when the infection was due to
serotypes 3 and 4.
”
“The risk of vaccine-associated dengue-enhanced disease due to serotypes 3 and 4 in seronegative children cannot be ruled out.”
It should be remembered that almost 100 percent of the cases currently circulating in Argentina correspond to
serotypes 1 and 2
.
And he adds that although in September 2023 the WHO Strategic Advisory Group of Experts on Immunization
recommended the use of the vaccine
for children aged 6 to 16 years living in environments with high disease burden, “significant knowledge gaps continue to exist.” regarding the safety and efficacy of this vaccine against type 3 and 4 viruses in reference seronegative people.”
In terms that are not entirely clear, PAHO says on the one hand that it accepts the recommendation of the Strategic Advisory Group on the
introduction of the vaccine in environments with high impact
of virus circulation, although on the other hand it states: "Currently PAHO does not recommend that include the dengue vaccine in the immunization programs of the countries.
What is also requested are
pilot tests and phase 4 studies
(in the field) to draw further conclusions.
The effectiveness of the dengue vaccine
Pablo Bonvehí, head of Infectious Diseases at CEMIC, told
Clarín
that “there is data that is concrete, from children and adolescents up to 16 years old, which shows an effectiveness of
61.2 percent in preventing
dengue disease and
84 percent to prevent complications
, in a follow-up of more than four and a half years.”
He added that “to control the disease there is a comprehensive strategy endorsed by the WHO, PAHO and different international organizations, which includes
vector management
,
waste disposal
and individual protection.
Another part is to strengthen the country's surveillance
capacity
to establish where the cases are, which group it affects.
Also improve
diagnostic capabilities
.
The fourth is to train personnel to care for dengue.
And then there is the
vaccine
as another component of dengue management.”
Specifically regarding the vaccine, Bonvehí considered: “Today we have a vaccine available.
The WHO recommended introduction in areas with
high viral circulation
and high prevalence of cases.
From 17 to 60 years there is immunogenicity data, through a bridging study, which says that one could consider that the vaccine is effective.”
Finally, the expert pointed out that “what needs to be defined is which are the areas with the greatest disease burden.
It is not a vaccine to
be introduced throughout the country
, but in provinces and even departments with a high disease burden, probably in young adult populations, which is where we see the most cases.
In fact,
Misiones and Salta
have already introduced the vaccine.
It would be important for effectiveness studies to be carried out in those provinces so that this helps CoNaIn to have parameters.”
Dengue and the lack of a comprehensive view
Carlos Ferreyra, former WHO consultant, president of the Climate, Life and International Health Alliance and promoter of the Dengue Control Unit in Córdoba between 2010 and 2013, said that “Argentina has desktop strategies and plans
,
many times without a budget. .
They are not anchored in one's own capabilities and are replaced by
reactive actions without substance
.
We are going to fall into the debate of vaccine yes or vaccine no, while the mosquito is increasingly
effective
in its achievements.”
Carlos Ferreyra in Geneva with the Spanish María Neira, director of the Department of Public Health and Environment of the WHO.
He recalled that “when there are strategies and plans - as in Córdoba with Law 9,666 and its updates - they are not implemented with the expected and appropriate seriousness.
This is what has happened in the last decade, since I have been a privileged actor in the fight against dengue in several Argentine provinces and
I see with astonishment
how the Ministries of Health have failed with the people and science."
He warned that “the damage and losses caused by dengue, as well as other diseases related to
Aedes aegypti
, can be
anticipated, reduced and prevented
through public health interventions, epidemiological intelligence, intersectoral actions and strengthening of vulnerable communities.”
But he pointed out that this implies having “a climate and health adaptation-resilience strategy of at least 10 years and
annual operational plans and territorial programs
, which do not imply large investments.
Meanwhile, effective technologies and vaccines will surely be achieved that will complete the strategic goals.”
P.S.