Vaccination Mandates after Recovery from Infection

During the pandemic, decisions not backed by data have, in some cases at least, resulted from lack of data. Various, conflicting and inconsistent recommendations on many things related to Covid resulted from insufficient or poor-quality data. There has also been a Wild West atmosphere, in which individual healthcare and non-healthcare institutions and, of course, states, made up their own regulations, presumably, at times, these institutions used the infamous, now mythical, spin wheel, borrowed from JHU AIDS unit, which pulmonologists were alleged to have used to decide which pts not to bronch and which pts to spin again. Individual SNFs, for instance, have different protocols for PPE. But, now, we do have a fair amount of quality data on reinfection rates. Shown below, these data do not support mandating vaccinations for HCWs (or probably anyone else) who is antibody positive after initial infection. These studies did not test for neutralizing antibodies, just IgG antibodies against the spike and nucleocapsid proteins. BTW, the data also suggest that anti-nucleocapsid IgG is more protective or a sign of additional protection compared with the anti-spike protein IgG. Of course, the Covid vaccines currently used in Europe and the US do not induce and cannot induce an anti-nucleocapsid antibody response. If I am missing something, please explain it to me. But these data are very impressive. Further, several HCWs who were infected and received one dose of an mRNA vaccine, including my brother, had bad reactions and refuse to get the second dose. Do they really need a second dose after infection and one dose? For the record, I am extremely pro-vaccine, whatever that means. I got vaccinated as soon as I could. I urged my priorly-infected brother to get vaccinated (he's still angry with me), my entire family is vaccinated (only 1 of 5 is in healthcare). I may or may not have registered many friends and family without their consent or knowledge to NJ vaccine site, so that they would be offered the vaccine as early as possible. Recent studies on reinfection - 1. A study from Oxford in NEJM prospectively looked at HCWs PCR positivity rate by serostatus.1 Seronegative HCWs’ rate = 1.09/10,000 days. For HCWs with IgG against the spike protein, PCR+ rate = 0.13/10,000 days. The ratio of PCR positivity incidence = 0.12 or 88% lower. The symptomatic PCR+ rate for seronegative HCWs = 0.60/10,000 days. 100% or both of the anti-spike IgG seropositive HCWs, who became PCR+, were asymptomatic. The IRR for symptomatic disease = 0. HCWs with anti-spike AND anti-nucleocapsid rate of PCR+ = 0.07/10,000 days. 2. A study from Lombardy in JAMA Int Med looked at pts with prior Covid, asymptomatic and symptomatic.2 During the follow-up (mean = 280 days), 0.31% of pts with a history of Covid was reinfected (5 reinfections in the 1579 positive patients. 1 was hospitalized.) Of the 13,496 pts without prior Covid, 3.9% developed primary infection. “The incidence rate ratio adjusted for age, sex, ethnicity, and the sanitarian area was 0.07 (95%CI, 0.06-0.08).” 3. A study from Geneva in CID also looked at seropositive vs. seronegative individuals at followed them for a mean of 8.5 months.3 Reinfection occurred in 1.0%. Primary infection occurred in 15.5% of seronegative controls. This decrease corresponded to a 94% reduction in hazard. 4. A study from the UK in Lancet looked at HCWs and found “we estimated that between June, 2020, and January, 2021, after controlling for other risk factors and for a given site, participants in the positive cohort had 99·8% lower risk of new infection than did participants in the negative cohort, adjusted IRR (aIRR) 0·002 (95% CI 0·00–0·01).” 4 References:

1. Lumley SF, et al. Antibody status and incidence of SARS-CoV-2 infection in health care workers. NEJM 2021 Feb 11;384:533-40. https://www.nejm.org/doi/full/10.1056/NEJMoa2034545 2. Vitale J, et al. Assessment of SARS-CoV-2 reinfection 1 year after primary infection in a population in Lombardy, Italy. JAMA Intern Med 2021. doi:10.1001/jamainternmed.2021.2959 3. Leidi A, et al. Risk of reinfection after seroconversion to SARS-CoV-2: a population-based propensity-score matched cohort study. Clin Infect Dis 2021. https://doi.org/10.1093/cid/ciab495 4. Hall VJ, et al. SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN). Lancet 2021 Apr 17;397(10283):1459-1469. DOI: 10.1016/S0140-6736(21)00675-9