Table 1 Advantages and disadvantages of various types of COVID19 vaccines in development
From: COVID-19 vaccines for patients with cancer: benefits likely outweigh risks
Vaccine type | COVID-19 vaccines furthest in development/approved | Advantages | Disadvantages |
|---|---|---|---|
Inactivated virus | SinoVac (CoronaVac + aluminum) SinoPharm (Inactivated whole virus SARS-CoV-2 + aluminum) | Entire virus, with all antigens presented Prior experience and technology – e.g., quadrivalent influenza vaccine Easier storage – does not need to be frozen | Need adjuvants to boost Poor inducers of CD8 + T-cell immunity Hard to mass-produce Large batches of live virus pose biosecurity risk |
Protein subunits | Novavax (NVX-CoV2373) Vector Institute (EpiVacCorona) | Can focus on antigens that generate neutralizing antibodies Does not introduce intact pathogen | Produced ex vivo, may not retain post-translational modifications or conformation Not efficiently presented Lower humoral and cellular response Require adjuvants to boost |
Replication incompetent adenoviral vector | AstraZeneca (ChAdOx1 nCoV-19; AZD1222) Johnson & Johnson (Ad26.COV2.S) CanSino Biologics (Ad5-nCoV) Gamaleya (Sputnik V) | Replication-defective, no new viral particles Avoids intact pathogen Mimics natural infection Elicits humoral and cellular immunity | Anti-vector immunity may interfere Lower efficacy if prior anti-vector immunity exists |
DNA | Inovio (INO-4800) | Mimic natural infection Elicits strong humoral and cellular immunity Avoids introducing pathogen Easier to mass-produce | Delivery into cell nucleus |
mRNA | Moderna (mRNA-1273) Pfizer-BioNTech (BNT162b2) | Delivery into cytoplasm Unable to integrate into host genome Elicit strong humoral and cellular immunity Avoids anti-vector immunity Avoids introducing pathogen Easier to mass-produce | Fragile – easily degraded Needs lipid nanoparticle for delivery Frozen for storage |