Irene Hartmann
03/10/2021 1:13 PM
Clarín.com
Society
Updated 03/10/2021 1:13 PM
Despite the dozen coronavirus vaccines approved in record time, the global demand for immunization remains voracious and is far from being met.
It seems pertinent to start looking at new horizons: to know
which vaccines could take a step forward in the coming months
, after being approved by the regulatory bodies of the countries.
But, first, what is the state of the question "vaccines"?
The World Health Organization (WHO) surveyed, as of March 5, more than 260 developments, the majority (182) in the preclinical phase, that is, they did not pass the animal test instance.
Specifically,
only 79 are in the "clinical" phase
, that is, they are tested in humans.
Of those that are more advanced, only
11 stepped into phase 3
, the most anticipated research instance, when thousands of people (trial volunteers) are administered the study medication, in order to evaluate
two
key
aspects
:
efficacy
, that is to say, to what extent the drug manages to alleviate the effects of the pathogen that it is trying to combat;
and
safety
, that is, the rigorous analysis of the effects of the drug on the body.
In the jargon, the famous
ESAVI
: Adverse Events Supposedly Attributable to Vaccination and Immunization.
In "normal" life, phase 3 drugs do not hit the streets for at least two years of research.
The pandemic shortened the times.
The premise is a shared assessment of the
risk-benefit
to which we are exposed.
That is, how risky it is to contract Covid in the face of the uncertainty of using vaccines approved in months.
The hallmark between different vaccines is the
technology or platform they use
.
There are several ways to systematize them.
Here is a detail of 11 vaccines that are in the "
minor leagues
", but advanced enough to be excited that they could hit the news table in these months.
Vaccines under the magnifying glass
The new pharmacological developments against the coronavirus under study.
vaccines licensed in at least one country
Source:
COVID-19 VACCINE TRACKER
Infographic:
Clarín
1. Whole pathogens
Whatever their basic technology, vaccines seek to generate a response from the immune system, so that the body can combat the effects of the coronavirus, in case of infection.
It should be noted that
no vaccine so far has proven the ability to prevent infection itself
.
On the other hand, the severe effects of the infection diminish and, of course, the chances that the disease will be
lethal
.
In a first section, the vaccines that use a
whole pathogen
to awaken the immune reaction
can be grouped
.
There are two subtypes: vaccines with
attenuated virus
and those with
inactivated virus
, such as Sinopharm, which has been used in the country recently to immunize older adults.
In phase 3, there are only
two unapproved developments yet
, both of inactivated virus.
The first - with no commercial name released for now - is carried out by the
Institute of Medical Biology
in collaboration with the
Chinese Academy of Medical Sciences
.
It is applied in two doses, four weeks apart.
Phase 3 began in December with more than 34,000 volunteers from Brazil and Malaysia and, although there is no preliminary data, the previous stages had shown an efficiency of over
95%
, according to the developers.
The second undertaking (known as
QazCovid-in
) has the seal of the Research Institute for Biological Safety, of the Republic of
Kazakhstan
.
Those responsible, who feel hopeful after having obtained a
96%
effectiveness in phases 1 and 2, hope to complete phase 3 at the end of March.
It is a vaccine designed to be administered in two doses, this time three weeks apart.
Vaccination of the elderly at Luna Park in Buenos Aires.
Photo: Juano Tesone
2. Proteins
In another chapter are the developments that take advantage of an "antigenic subunit" or "
protein subunit
".
These are protein-based vaccines, sometimes whole, sometimes fragments.
There are familiar examples of this technology, such as influenza A and B (influenza) vaccines.
The term "
recombinant
"
is often associated with these developments
.
It actually has to do with the way in which the proteins in question are obtained, which could be by synthesis in the laboratory or after the genetic modification of microorganisms (bacteria or fungi) so that they synthesize the protein of interest.
This last strategy implies a “genetic re-combination” (this is the case of the hepatitis B vaccine), although, it should be noted,
they are not vaccines that include genetic material
, as will be seen in group 3.
One of the best known is the NVX-CoV2373, from the American company
Novavax
, which received a great economic incentive from the government of that country, and already reported auspicious preliminary results:
89.3%
effective.
In addition, earlier this year, the company announced that it expected approval from the FDA in May, and the European Regulatory Authority (EMA) is already analyzing the approval.
However, beyond phase 3 being carried out (with 15,000 volunteers from England and another 30,000 from the United States, Mexico and Puerto and Rico), it should be remembered that the phase 2 trial carried out with 4,400 volunteers from South Africa yielded an efficacy just above
50%
, which raised doubts about the ability of this drug to combat the different variants of coronavirus.
Another to consider is the
COVAXX
vaccine
(UB-612), a subsidiary of the US pharmaceutical company United Biomedical, which is progressing simultaneously with phases 2 and 3 (something, in this context of trouble, common to several companies).
Efficacy data is not reported on the official page of this development, but it was circulated that the company has
advance purchase commitments
for more than 140 million doses for countries such as Brazil, Ecuador and Peru, which could reveal some international confidence in the project .
Clover
Biopharmaceuticals Inc., together with GSK and Dynavax, also carry out phases 2 and 3 of a vaccine against Covid that involves the protein S of the coronavirus, but also an "adjuvant", a substance with which they seek to enhance the response of the virus. immune system.
At the end of this note, the company made a modification of the adjuvant involved, so phases 2 and 3 were restarted. The promise of this drug lies in nothing less than a particularity: the possibility of
storing the doses for up to a month at room temperature
.
There is also the North American
CoVLP
(from Medicago Inc. and GSK), which has been carrying out phases 2 and 3 since November, with more than 30,000 volunteers who have already received the two doses 21 days apart.
It is worth noting that Medicago is a company founded in part by the
Philip Morris cigarette
brand
, which innovated in an original immune development.
They basically apply viral genes to a wild species called
nicotiana benthamiana
(related to tobacco), so that plant cells develop protein layers that mimic the viral agent.
The vaccine also uses an "adjuvant", in this case, produced by
GSK
, which in phase 1 seems to have given promising immunogenicity results, although no specific figures have been released, for now.
Finally, the Chinese company
Anhui Zhifei Longcom
and the Institute of Microbiology of the Chinese Academy of Sciences teamed up to develop a vaccine technologically similar to those of Novavax and Medicago, which is identified with the name "ZF2001".
It is being evaluated in a phase 3 trial, with 29,000 volunteers from China.
The peculiarity of this drug is that it is administered in
three doses
: the first at four weeks and the second, four weeks later.
3. Genetics
If it is accepted that group 1 includes the most traditional or historical vaccine technologies, and that group 2 adds more modern platforms, group 3 should be defined as
"cutting edge" vaccines
.
In fact, genetically based platforms
had not been used in any vaccine
(against any infectious agent) until the pandemic, which arouses optimism in some and caution in others.
The Curevac vaccine under investigation at the UMC hospital in Amsterdam.
Photo: EFE
But the truth is that there are several vaccines already approved and in use with these technologies.
They are of two types.
On the one hand, those that
convey DNA through a certain viral vector
(replicative or non-replicative, they are two different formats), as if a kind of "
virus-taxi
" were transporting the genetic information of the coronavirus with which it is expected to awaken the reaction. immune in the body.
Two that use this technology are Sputnik V and AstraZeneca (or its Indian version, the Covishield vaccine).
The "taxi", in these cases, are different types of adenovirus, the pathogens that cause common colds.
A second group is made up of genetic vaccines that take advantage of the technology known as
messenger RNA
(mRNA).
There are two licensed in the world: the Pfizer vaccine and the Moderna vaccine.
There is an advanced and vigorous development of this last type: the German vaccine from
CureVac
(CVnCoV), a company created in 2000, dedicated to the development of vaccines with mRNA.
The support that this venture received is not less: in January they announced agreements with giants of the sector such as Bayer, GSK and Novartis, and there is a precedent that stands out, which is a collaboration agreement with the Tesla company, owned by Elon Musk, for the development of microfactories of mRNA adaptable to any latitu.
The sales commitments for this vaccine, currently in phase 3 (with more than 35,000 volunteers receiving two doses four weeks apart) include sales agreements for the European Union for 225 million doses.
In fact, the company's expectation is to produce
300 million doses this year and 1 billion in 2022
.
As for the first subgroup, those that carry
DNA
, there are several ...
One is being produced in Japan.
It is called
AG0301,
and it goes through phases 2 and 3 together, although with very few volunteers (less than 1,000).
It is the result of the work of
AnGes
, Takara Bio and the University of Osaka, and is applied in two doses only two weeks apart.
Another with few volunteers (almost 6,700) in phase 2/3 is the American
Inovio
vaccine
(INO-4800), also two doses, 28 days apart.
According to information from
The New York Times
, in these months, the company (known for its trials of HIV and Zika vaccines) entered into a series of legal disputes with shareholders, which would have delayed all development, which would now be in progress. March.
The third and final phase 3 vaccine is a work by the
Indian company Zydus Cadila
.
It's called ZyCoV-D and it's given in three doses, four weeks apart.
In December they announced the start of phase 3, with 30,000 volunteers.
And they assured what many would like to achieve: have the vaccine ready "now", in March 2021.
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