The National Epidemiology and Microbiology Research Center in Gamaleya, part of the Russian Ministry of Health, developed a vaccine against COVID-19 known as Sputnik V. Ö Gam-Covid-Vac. Gamaleya announced in December that the vaccine was 91.4 percent effective. Russia uses it in its mass vaccination campaign and it is now being distributed in Argentina, Belarus and other countries.
A fragment of the coronavirus
The SARS-CoV-2 virus is filled with proteins that it uses to enter human cells. These proteins, called spikes, are tempting targets for potential vaccines and treatments.
Gen de
Protein from
the summit
Gen de
Protein from
the summit
Sputnik V relies on the virus’ genetic instructions to put the spike protein together. However, unlike Pfizer BioNTech and Moderna vaccines, which store instructions in single-stranded or single-stranded RNA, Sputnik V uses double-stranded DNA.
DNA in adenoviruses
The researchers developed their vaccine from various adenoviruses, a type of virus that causes colds. They added the coronavirus spike protein gene to two types of adenoviruses, one called Ad26 and one called Ad5, and modified them so they could enter cells without replicating.
Sputnik V is the result of decades of research into adenovirus vaccines. The first was approved for general use last year: an Ebola vaccine from Johnson & Johnson. Some other COVID-19 vaccines are also based on adenoviruses, like one from Johnson & Johnson using Ad26 and another from Oxford University and AstraZeneca using a chimpanzee adenovirus.
Cell entry
After the Sputnik V vaccine is injected into a person’s arm, adenoviruses collide with cells and attach to proteins on their surface. The cell wraps the virus in a bubble and absorbs it. Inside, the adenovirus escapes from the bladder and travels to the nucleus, the chamber in which the cell’s DNA is located.
Enveloped virus
in a bubble
Enveloped virus
in a bubble
Enveloped virus
in a bubble
virus
packed in
a bubble
virus
packed in
a bubble
virus
packed in
a bubble
virus
wrapped up
in one
bladder
virus
wrapped up
in one
bladder
The adenovirus inserts its DNA into the nucleus. The adenovirus is modified so that it doesn’t make copies of itself, but the cell can read the gene for the coronavirus spike protein and copy it into a molecule called messenger RNA, or mRNA.
Spike protein assembly
The mRNA leaves the nucleus and the cell’s molecules read their sequence and begin assembling spike proteins.
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Combine three
Spike proteins
Fragments
of spikes
and proteins
The gifts
Fragments
top
Some of the spike proteins produced by the cell form spikes that migrate to its surface and spread their tips. The vaccinated cells also separate into fragments some of the proteins that they present on their surface. The immune system can then recognize these protruding spikes and spike protein fragments.
Adenovirus also triggers the immune system by activating the cell’s alarm systems. The cell sends out warning signals to activate nearby immune cells. With this alarm, Sputnik V makes the immune system react more strongly to spike proteins.
Intruder detection
When a vaccinated cell dies, its remains contain spike proteins and protein fragments, which can then take up a type of immune cell called an antigen-presenting cell.
Remains of a
dead cell
CELL
MODERATOR
OF ANTIGENS
Digestion of
Proteins
The gifts
a fragment of
Spike protein
Remains of a
dead cell
CELL
MODERATOR
OF ANTIGENS
Digestion of
Proteins
The gifts
a fragment of
Spike protein
Remains of a
dead cell
CELL
MODERATOR
OF ANTIGENS
Digestion of
Proteins
The gifts
a fragment of
Spike protein
The cell has fragments of the spike protein on its surface. When other cells, called helper T lymphocytes, recognize these fragments, they can sound the alarm and prompt other immune cells to fight infections.
Formation of antibodies
Other immune cells called B lymphocytes could collide with coronavirus spikes on the surface of vaccinated cells or with fragments of floating spike proteins. Some B-lymphocytes may be able to attach to the spike proteins. Later, when helper T lymphocytes activate these B lymphocytes, they begin to multiply and secrete antibodies that attack the spike protein.
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
protein
associated
on the surface
Activation of
B lymphocytes
Corresponding proteins
on the surface
Activation of
B lymphocytes
Corresponding proteins
on the surface
Activation of
B lymphocytes
Corresponding proteins
on the surface
Alto al Virus
Antibodies can stick to the coronavirus spikes, marking the virus for destruction, and blocking the infection by preventing the spikes from attaching to other cells.
Suppression of infected cells
Antigen presenting cells can also activate another type of immune cell called a cytotoxic T lymphocyte to search for and destroy coronavirus infected cells that present spike protein fragments on their surface.
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
CELL
MODERATOR
OF ANTIGENS
Presentation of
a fragment of
Spike protein
LYMPHOCYTE T.
CYTOTOXIC
ACTIVATED
Begins to suppress
to the infected cell
Two cans
Some researchers fear that if our immune system receives an adenovirus vaccine, it may make antibodies against that vaccine, so a second dose will not have any effect. To avoid this, the Russian researchers used one type of adenovirus, Ad26, for the first dose and another, Ad5, for the second.
Second dose
21 days
then:
Ad5
Second dose
21 days later: Ad5
Second dose
21 days later: Ad5
The COVID-19 vaccines developed with adenovirus are more resistant than the mRNA vaccines from Pfizer and Moderna. DNA isn’t as fragile as RNA, and the adenovirus’ hard protein shell protects the genetic material it contains. This means that Sputnik V can be refrigerated and does not require very low storage temperatures.
Memory of the virus
The Gamaleya Institute announced that the Sputnik V vaccine has an efficacy rate of 91.4 percent but has yet to publish a scientific paper that will reveal all the details of the clinical trial.
Two doses of the color-coded Sputnik V vaccine.Russian direct investment fund through Environmental Protection Agency
It is not yet clear how long the vaccine could take to protect. The levels of antibodies and cytotoxic T lymphocytes elicited by the vaccine may decrease in the months following inoculation. However, the immune system also contains special cells called memory B and T cells that can hold information about the coronavirus for years or even decades.
Additional reporting from Yuliya Parshina-Kottas. Sources: National Center for Information on Biotechnology; Nature; Lynda Coughlan, University of Maryland Medical School.
