Recently, Russia claimed to develop the first COVID-19 vaccine named Sputnik V.The vaccine claimed to provide immunization to people and protect them from the virus for up to two years. However, this —potential—coronavirus vaccine is yet to pass the advanced trials and lacks evidence to back their claims.
Following the announcement of the vaccine, the senior adviser to WHO’s director-general, Dr. Bruce Aylward said “We don’t have sufficient information at this point to make a judgment.”
Most vaccines are not approved for human studies…
The vaccine candidates for COVID-19 have to pass the pre-clinical barriers to reach phase-I of human testing. Several vaccines that are under design or preclinical development are not approved for human studies because of toxicity, ineffectiveness to induce immune responses or dosing failures in laboratory animals, or due to underfunding. The probability of candidate vaccines to successfully cross the preclinical barriers and reach human testing is 41-57%.
The race for the first COVID-19 vaccine is more complicated than it seems. There are altogether 226 candidate vaccines under the trial of which, only 29 vaccines have reached the clinical evaluation.
- Phase-I: Small groups of people receive the trial vaccine
- Phase-II: The clinical study is expanded and the vaccine is given to people who have characteristics like age and physical health, similar to those for whom the new vaccine is intended for.
- Phase-III: The vaccine is given to thousands of people and tested for efficacy and safety.
(*Many vaccines undergo Phase IV formal, ongoing studies after the vaccine is approved and licensed*)
Under the 29 candidate vaccines, only 3 have reached the Phase-III trials.
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Moderna /NIAID
- Vaccine Platform: RNA
- Type of Candidate Vaccine: LNP-encapsulated mRNA
- Number of doses: 2
- Timing of doses: 0,28 Days
- Adverse Effects:
Fever, Fatigue, Headache, Muscle ache, and Pain at the Injection Site
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BioNTech/Fosun Pharma/Pfizer
- Vaccine Platform: RNA
- Type of Candidate Vaccine: 3 LNP-mRNAs
- Number of doses: 2
- Timing of doses: 0,28 Days
- Adverse Effects:
Dose-dependent and moderate including pain at the injection site, Fatigue, Headache, Chills, Muscle and joint pain, Fever
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University of Oxford/AstraZeneca
- Vaccine Platform: Non-Replicating Viral Vector
- Type of Candidate Vaccine: ChAdOx1-S
- Number of doses: 1
- Timing of doses: –
- Adverse Effects:
Pain at the injection site, Headache, Fever, Chills, Muscle ache, Malaise in more than 60% of participants; paracetamol allowed for some participants to increase tolerability
