Subunit

Purified sub-

units from

virus

material

Low/yes/short

protection/yes

Whole viruses are

disrupted by detergents

and purified into sub-

units

No risk of infection as

virus is disrupted and

split, required biosafety

level in production

determined by

pathogenicity of the virus,

inactivation and

detergents might

influence antigen

structure

ng protein/dose

Mammalian &

avian cells

influenza

Recombinant

sub-unit

Viral antigen

(protein)

Medium/yes/short

protection/yes

Recombinant expression

of viral genes to

produce virus proteins

Low risk as antigens have

no viral genome, lower

immune response as some

virus antigens are missing

ng protein/dose

Mostly insect

cells,

HEK293

and CHO

HA

(hemagglu-

tinin) from

influenza virus

Recombinant

virus-like

particle

Virus-like

particle

(VLP)

Medium/yes/short

protection/yes

Recombinant expression

of viral genes to

produce VLPs

Low risk as VLPs have no

viral genome, lower

immune response as some

virus antigens are missing

ng protein/dose

Mostly insect

cells,

HEK293

and CHO

HA from

influenza virus

Recombinant

vector/

chimeric

virus

Viral antigen

(protein)

plus vector

whole virus

High/yes/short

protection/yes

Attenuated or

recombinant viral

vector express viral

antigen in the

vaccinated person,

chimeric virus displays

recombinant antigen on

its surface

Antigens from vector can

serve as adjuvant, non-

replicating vectors makes

this interesting for viruses

of high biosafety level

e.g., ng protein/

dosee.g., 1E08

vector units/

dose/cold

chain

Mammalian,

avian and

insect cells

VSV for Ebola,

YFV, AdV

(adenovirus)

for SARS-

CoV-2 (severe

acute

respiratory

syndrome

corona virus

type 2)

mRNA

Viral antigen

(protein)

High/yes/not enough

data/no

Viral antigen is

expressed in the

vaccinated person from

the introduced mRNA,

mRNA is packed in

lipid particle to be

No risk of infection, no

risk of integration of

mRNA into genome,

relatively new

technology, possible

concerns not fully clear

0.1-100 µg/

dosecold

chain−50 to

−15°C, 2−8°C

30 days and up

Enzymatic,

lipid

chemistry

SARS-CoV-2

(Continued)

Upstream processing for viral vaccines

85