Mary Wilson
Well-known member
ACCEPTED MANUSCRIPT
Infectious Diseases Society of America
https://doi.org/10.1093/cid/ciab070
Published: 27 January 2021
Paul Bieniasz
Dear Editor:
The extraordinarily rapid development of 2-dose, prime-boost SARS-CoV-2 mRNA vaccine regimens with excellent efficacy (~95%) is a key milestone in the COVID19 pandemic [1, 2]. These mRNA vaccines will provide an important tool to protect against severe disease and death, at least in developed nations.
In phase 3 clinical trials, prime and boost mRNA vaccine doses were given 21 or 28 days apart, with the vast majority of the monitoring period occurring after the boosting dose. Nevertheless, based on the observation of an efficacy signal following the priming dose and preceding the boosting dose[1, 2], it has been proposed (and adopted as policy in the UK) that the second, boosting dose should be withheld for several months. This would allowmore individuals to receive a ‘prime-only’ vaccine regimen in the initial months of vaccineroll-out. Here, I present arguments against the adoption of such a strategy.
The first set of arguments center on the evidence of effectiveness, or lack thereof, for prime-only SARS-CoV-2 mRNA vaccination. The purported efficacy of prime-only regimens is based on a small number of infections that occurred over an extremely short time period, (~day 12 to ~day 21 or 28) between the prime and the boost[1, 2]. We simply do not know whether prime-only recipients will be protected beyond day 21 or 28 – this has not been tested in any clinical trial and assertions about effectiveness beyond day 21-28 are speculative. Even less certain is whether a prime-only regimen will allow onward transmission of SARS-CoV-2. An important benefit of the most effective vaccines, and aconcept underlying ‘herd’ immunity, is that is that vaccines protect not only the recipient, butalso to their subsequent contacts. At present, the degree to which 2-dose, prime-boosted mRNA vaccine recipients become asymptomatically infected and allow onward transmission is being assessed. We have essentially no information (certainly none beyond 21-28 days ...
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https://watermark.silverchair.com/c...1IGp3A-ovB6P7V03KhdiCMJK292GAqVEL2HWEt4rrsrgg
Downloaded From: https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciab070/6121510#.YBxVhMJdgtV.twitter
Infectious Diseases Society of America
https://doi.org/10.1093/cid/ciab070
Published: 27 January 2021
Paul Bieniasz
Dear Editor:
The extraordinarily rapid development of 2-dose, prime-boost SARS-CoV-2 mRNA vaccine regimens with excellent efficacy (~95%) is a key milestone in the COVID19 pandemic [1, 2]. These mRNA vaccines will provide an important tool to protect against severe disease and death, at least in developed nations.
In phase 3 clinical trials, prime and boost mRNA vaccine doses were given 21 or 28 days apart, with the vast majority of the monitoring period occurring after the boosting dose. Nevertheless, based on the observation of an efficacy signal following the priming dose and preceding the boosting dose[1, 2], it has been proposed (and adopted as policy in the UK) that the second, boosting dose should be withheld for several months. This would allowmore individuals to receive a ‘prime-only’ vaccine regimen in the initial months of vaccineroll-out. Here, I present arguments against the adoption of such a strategy.
The first set of arguments center on the evidence of effectiveness, or lack thereof, for prime-only SARS-CoV-2 mRNA vaccination. The purported efficacy of prime-only regimens is based on a small number of infections that occurred over an extremely short time period, (~day 12 to ~day 21 or 28) between the prime and the boost[1, 2]. We simply do not know whether prime-only recipients will be protected beyond day 21 or 28 – this has not been tested in any clinical trial and assertions about effectiveness beyond day 21-28 are speculative. Even less certain is whether a prime-only regimen will allow onward transmission of SARS-CoV-2. An important benefit of the most effective vaccines, and aconcept underlying ‘herd’ immunity, is that is that vaccines protect not only the recipient, butalso to their subsequent contacts. At present, the degree to which 2-dose, prime-boosted mRNA vaccine recipients become asymptomatically infected and allow onward transmission is being assessed. We have essentially no information (certainly none beyond 21-28 days ...
NOTE: This content is only available as a PDF.
https://watermark.silverchair.com/c...1IGp3A-ovB6P7V03KhdiCMJK292GAqVEL2HWEt4rrsrgg
Downloaded From: https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciab070/6121510#.YBxVhMJdgtV.twitter