Necessity of Covid-19 vaccination in previously infected individuals | Hacker News Reader

Necessity of Covid-19 vaccination in previously infected individuals

medrxiv.org

14 pointsheshiebee4 comments

> Not one of the 1359 previously infected subjects who remained unvaccinated had a SARS-CoV-2 infection over the duration of the study. In a Cox proportional hazards regression model, after adjusting for the phase of the epidemic, vaccination was associated with a significantly lower risk of SARS-CoV-2 infection among those not previously infected (HR 0.031, 95% CI 0.015 to 0.061) but not among those previously infected (HR 0.313, 95% CI 0 to Infinity).

> Conclusions Individuals who have had SARS-CoV-2 infection are unlikely to benefit from COVID-19 vaccination, and vaccines can be safely prioritized to those who have not been infected before.

Nice concise summary - It's worth noting this publication does not appear to have been peer-reviewed yet.

That said, the relatively large sample size (52238 Employees of the Cleveland Clinic Health System) provides strong statistical power, which should give the results serious credibility.

If these results hold (ie there are no systematic errors in their design or analysis), the next logical step would appear to be a similar analysis which accounts for newer variants of concern (eg delta).

Is anyone aware of such publications?

Is anybody aware of any reason there would be negative effects to getting a vaccination for previously infected people?

I had Covid in April. My doc, with a shrug, said "you should probably wait 90 days to get vaccinated?"

So I was looking to get my shots now, because the world at large seems to think that only vaccinations matter and that immunity from prior infection somehow fades in a few months. But I'm just a little concerned that the immune response to the vaccines might be much greater for me.

Here are some peer-reviewed publications that can help answer your question [1][2].

To summarize in my own words: The early literature appears to support the fact that your immune response to the vaccine will be greater because you've previously been infected & recovered. According to [1] you may be more likely to suffer from symptomatic side effects from the mRNA vaccines, however the risk of hospitalization and death remains very low.

Furthermore, evidence from [2] indicates that you likely acquired durable long-term immunity, such that the necessity or utility of getting multiple vaccine doses is questionable right now.

Highlights from [1]:

- "We wondered what the response would be to the first vaccine dose in persons with previous Covid-19"

- "We took advantage of our ongoing institutional review board–approved, longitudinal PARIS (Protection Associated with Rapid Immunity to SARS-CoV-2) study to provide a limited snapshot of the antibody responses in 110 study participants with or without documented preexisting SARS-CoV-2 immunity (mean age overall, 40.0 years [range, 24 to 68; ≥60 years, 8%]; 67 seronegative participants [64% female] with a mean age of 41.3 years and 43 seropositive participants [59% female] with a mean age of 41.4 years)"

- "Repeated sampling after the first dose indicates that the majority of seronegative participants had variable and relatively low SARS-CoV-2 IgG responses within 9 to 12 days after vaccination"

- "In contrast, participants with SARS-CoV-2 antibodies at baseline before the first vaccine injection rapidly developed uniform, high antibody titers within days after vaccination"

- "The antibody titers of vaccinees with preexisting immunity were 10 to 45 times as high as those of vaccinees without preexisting immunity at the same time points after the first vaccine dose (e.g., 25 times as high at 13 to 16 days) and also exceeded the median antibody titers measured in participants without preexisting immunity after the second vaccine dose by more than a factor of 6"

- "Although the antibody titers of the vaccinees without preexisting immunity increased by a factor of 3 after the second vaccine dose, no increase in antibody titers was observed in the Covid-19 survivors who received the second vaccine dose"

- "Overall, both vaccines (156 participants received the Pfizer vaccine and 74 the Moderna vaccine) had no side effects that resulted in hospitalization"

- "Vaccine recipients with preexisting immunity had systemic side effects at higher frequencies than those without preexisting immunity (fatigue, headache, chills, muscle pain, fever, and joint pain, in order of decreasing frequency)"

- "Because a convenience sample was used and only participants with available data were studied, caution is needed until the full data set, including side effects occurring after the first as well as the second vaccine dose, can be assessed"

[1] Antibody Responses in Seropositive Persons after a Single Dose of SARS-CoV-2 mRNA Vaccine (April 2021) https://www.nejm.org/doi/pdf/10.1056/NEJMc2101667?articleToo...

[2] SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans (May 2021) https://www.nature.com/articles/s41586-021-03647-4.pdf

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