Hey John. Do you think vaccine diturbutors should check essential workers for antibodies before giving the vaccine (not wasting vaccines on healthy people that already have antibodies as it might not help)?
Also is there reason to believe there is a differece in immunity time between vaccinated people and people who had the disease?
You're asking a great question. I've addressed this to a limited extent in previous writing for this newsletter, but recently, I've been thinking about this a lot.
I do not think that natural immune responses to SARS-CoV-2 are as consistently strong as the immune responses generated by the Pfizer and Moderna vaccines. I base this on data from the Phase 2 trials where antibody levels in convalescent plasma controls were a lot more inconsistent than levels in plasma samples from fully-vaccinated patients.
For this reason, I do not think that natural immune responses are adequate protection such that a person who is antibody-positive could skip the vaccine.
I think that addresses both of your specific questions.
However, on Twitter the other day, Dr. Florian Krammer raised an intriguing possibility: do people with preexisting immunity to SARS-CoV-2 actually need 2 doses of vaccine? We would expect that anyone who tests antibody-positive would have some amount of memory B cells, ready to respond to a new infection. These memory B-cells are the same thing that the booster dose in a normal vaccination course is looking to activate, expand, and reinforce. It's possible that a person's natural infection might be a sufficient "prime" for them to only need a single, "booster" (not really a booster) dose of vaccine. This possibility is very interesting to me, because in places like NYC, almost 25% of people have already been infected with SARS-CoV-2. Giving them only one dose would free up 12.5% of our vaccine doses, and potentially help us to fully vaccinate a 6.25% larger population.
As always, I'd like to see some kind of clinical study at least showing a booster effect on patients with past infection when receiving a first dose of vaccine, but even so I think this suggestion might just work, unlike some other ideas that I'm more skeptical about.
Hey, John, would you like to correct Nature? In the Nature Briefing, they wrote, "The COVID vaccine developed by Moderna, which was authorized by US regulators last month, can provide protection against COVID-19 within two weeks of the first dose, according to the results of a large clinical trial. (Reference: New England Journal of Medicine paper)"
However, the actual paper (https://www.nejm.org/doi/10.1056/NEJMoa2035389) says, "The finding of fewer occurrences of symptomatic SARS-CoV-2 infection after a single dose of mRNA-1273 is encouraging; however, the trial was not designed to evaluate the efficacy of a single dose, and additional evaluation is warranted."
I think Nature's description is at best misleading. What about you?
I see how it could appear misleading, but the way they have phrased it is accurate. 50% vaccine efficacy is still efficacy. People working on an HIV vaccine would be amazed at 50% efficacy. The problem is that for COVID-19, 50% protection is probably not adequate given how contagious the disease is. I think perhaps they should have considered noting that this did not exceed the expected minimum bar for adequate protection.
Still, strictly speaking, what they said here is true.
Hey John. Do you think vaccine diturbutors should check essential workers for antibodies before giving the vaccine (not wasting vaccines on healthy people that already have antibodies as it might not help)?
Also is there reason to believe there is a differece in immunity time between vaccinated people and people who had the disease?
You're asking a great question. I've addressed this to a limited extent in previous writing for this newsletter, but recently, I've been thinking about this a lot.
I do not think that natural immune responses to SARS-CoV-2 are as consistently strong as the immune responses generated by the Pfizer and Moderna vaccines. I base this on data from the Phase 2 trials where antibody levels in convalescent plasma controls were a lot more inconsistent than levels in plasma samples from fully-vaccinated patients.
For this reason, I do not think that natural immune responses are adequate protection such that a person who is antibody-positive could skip the vaccine.
I think that addresses both of your specific questions.
However, on Twitter the other day, Dr. Florian Krammer raised an intriguing possibility: do people with preexisting immunity to SARS-CoV-2 actually need 2 doses of vaccine? We would expect that anyone who tests antibody-positive would have some amount of memory B cells, ready to respond to a new infection. These memory B-cells are the same thing that the booster dose in a normal vaccination course is looking to activate, expand, and reinforce. It's possible that a person's natural infection might be a sufficient "prime" for them to only need a single, "booster" (not really a booster) dose of vaccine. This possibility is very interesting to me, because in places like NYC, almost 25% of people have already been infected with SARS-CoV-2. Giving them only one dose would free up 12.5% of our vaccine doses, and potentially help us to fully vaccinate a 6.25% larger population.
As always, I'd like to see some kind of clinical study at least showing a booster effect on patients with past infection when receiving a first dose of vaccine, but even so I think this suggestion might just work, unlike some other ideas that I'm more skeptical about.
Hey, John, would you like to correct Nature? In the Nature Briefing, they wrote, "The COVID vaccine developed by Moderna, which was authorized by US regulators last month, can provide protection against COVID-19 within two weeks of the first dose, according to the results of a large clinical trial. (Reference: New England Journal of Medicine paper)"
However, the actual paper (https://www.nejm.org/doi/10.1056/NEJMoa2035389) says, "The finding of fewer occurrences of symptomatic SARS-CoV-2 infection after a single dose of mRNA-1273 is encouraging; however, the trial was not designed to evaluate the efficacy of a single dose, and additional evaluation is warranted."
I think Nature's description is at best misleading. What about you?
I see how it could appear misleading, but the way they have phrased it is accurate. 50% vaccine efficacy is still efficacy. People working on an HIV vaccine would be amazed at 50% efficacy. The problem is that for COVID-19, 50% protection is probably not adequate given how contagious the disease is. I think perhaps they should have considered noting that this did not exceed the expected minimum bar for adequate protection.
Still, strictly speaking, what they said here is true.