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Previous Infection, Action of Natural Immune System, Confer Robust Immunity
updated 3 weeks, 3 days ago
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<b An Oxford Study >b
“In summary, by pooling data from unvaccinated and Pfizer-BioNTech and AstraZeneca vaccinated HCWs, <b we show that natural infection resulting in detectable anti-spike antibodies [emphasis mine] and 2 doses of vaccine both provide <b robust protection against SARS-CoV-2, including against the B.1.1.7 variant of concern [Alpha variant].”
A discussion on facing COVID-19 by yourself (meaning that your immune system is going solo against SARS-CoV-2).
Why are the vaccinated people blaming unvaccinated, previously infected, seropositive people for spreading the Delta variant TODAY, and in a moment, in the near or far future, the unvaccinated survivors – have already infected the future victims of COVID-19, in pre-crime mentality – an atrocity of logic, to put it in mild terms.
“Prior SARS-CoV-2 infection protects against polymerase chain reaction (PCR)-confirmed symptomatic/asymptomatic SARS-CoV-2 infection by 83–88% up to 5–6 months postinfection, with greater reductions in symptomatic reinfections [2–4]. Ongoing longitudinal studies are required to determine the duration of protection conferred by natural immunity; however evaluating this will be more difficult with widespread vaccination.”
“Reinfection rates following natural infection have not been shown to be higher in studies using SGTF as a proxy for B.1.1.7, [20, 22] even though variably decreased sensitivity to neutralization by monoclonal antibodies, convalescent plasma and sera from vaccinated individuals has been observed in vitro for B.1.1.7 [23–34]”
“<b “Study Groups”>b
“Staff members were classified into 5 groups: (a) unvaccinated and consistently seronegative during follow-up; (b) unvaccinated and ever seropositive; (c) vaccinated once, always seronegative prior to vaccination; (d) vaccinated twice, always seronegative prior to first vaccination; (e) vaccinated (once or twice) and ever seropositive prior to first vaccination. The latter group were combined as relatively few staff were previously seropositive and vaccinated twice. Vaccinated groups were considered at-risk of infection >14 days after each vaccine dose…”
“Staff remained at risk of infection in each follow-up group until the earliest of the study end, first vaccination, second vaccination in previously seronegative HCWs, a positive PCR test, or for unvaccinated HCWs, a positive antibody test. Staff could transition from one group to another following seroconversion or vaccination after 60 or 14 days, respectively, disregarding any PCR-positive result during this crossover period, including the 14 days following a second vaccination for previously seronegative HCWs vaccinated twice.”
“<b “Outcomes” >b
“The main outcome was PCR-confirmed symptomatic SARS-CoV-2 infection. We also considered any PCR-positive result (ie, either symptomatic or asymptomatic). To assess the impact of the B.1.1.7 variant on (re)infection risk, we also analyzed PCR-positive results with and without SGTF, and those confirmed as B.1.1.7 on sequencing.”
“<b “Incidence of PCR-Confirmed Symptomatic SARS-CoV-2 Infection” >b
“PCR-confirmed symptomatic SARS-CoV-2 infection in HCWs peaked in December 2020 and January 2021, similarly to local community-based infection rates [40] . . Also, 294 unvaccinated seronegative HCWs were infected, 1 unvaccinated seropositive HCW and 32 vaccinated HCWs > 14 days post first vaccine (1 previously seropositive). Compared to unvaccinated seronegative HCWs who had the highest rates of infection, incidence was 98% lower in unvaccinated seropositive HCWs…”
“<b “Incidence of Any PCR-Confirmed Symptomatic or Asymptomatic SARS-CoV-2 Infection” >b
“Rates of any PCR-positive result, irrespective of symptoms, were highest in unvaccinated seronegative HCWs (635 cases), with 85% lower incidence in unvaccinated seropositive HCWs…”
“<b “Impact of Antibody Status and Vaccination on Viral Loads” >b
“Viral loads were higher, that is, Ct values lower, in symptomatic infections (median [IQR] Ct: 16.3 [IQR 13.5–21.7]) compared to asymptomatic screening (Ct: 20 [IQR 14.5–29.5]) ... Unvaccinated seronegative HCWs had the highest viral loads (Ct: 18.3 [IQR 14.0–25.5]), followed by vaccinated previously seronegative HCWs (Ct: 19.7 [IQR 15.0–27.5]); unvaccinated seropositive HCWs had the lowest viral loads (Ct: 27.2 [IQR 18.8–32.2])…”
“<b “Discussion” >b
“Immunity induced by natural infection and vaccination was robust to lineage, including cases confirmed to be B.1.1.7 by whole-genome sequencing, at least within the power of the study.”
“In summary, by pooling data from unvaccinated and Pfizer-BioNTech and AstraZeneca vaccinated HCWs, we show that natural infection resulting in detectable anti-spike antibodies and 2 doses of vaccine both provide robust protection against SARS-CoV-2 infection, including against the B.1.1.7 variant of concern.”
Source:
https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciab608/6314286
https://www.yalemedicine.org/news/5-things-to-know-delta-variant-covid
1. Delta is more contagious than the other virus strains. Delta is the name for the B.1.617.2. variant, a SARS-CoV-2 mutation that originally surfaced in India. The first Delta case was identified in December 2020, and the strain spread rapidly, soon becoming the dominant strain of the virus in both India and then Great Britain.
However…
Pfizer seems to claim a victory concerning the Delta variant.
The findings published in the journal Immunity, the delta was unable to escape all but one of the antibodies tested, which were produced by individuals in response to the Pfizer COVID-19 vaccination.
The question in India about natural immunity is not clarified as “yes” or “no” in the following:
India is currently reporting around 40,000 cases and 500 deaths a day. Of the total dedicated COVID-19 hospital beds in the capital, New Delhi, only 2% are currently occupied. Business activity has returned to pre-pandemic levels, even though the numbers of cases and deaths are still much higher than they were after the first wave.
Following the second wave, a very high number of Indian people have COVID-19 antibodies. In recent surveys conducted by health authorities, two-thirds of India’s population have been found to have them. Considering less than 30% of Indians had received at least one vaccine dose when the surveys were conducted, this clearly highlights how widely the virus spread during the second wave.
With the virus having overwhelmed the country’s already struggling healthcare system, India is now trying to identify and fill the gaps that became visible during the second wave.
Alongside tighter border controls to prevent cases being imported, the country has invested in promoting COVID-appropriate behavior among the public, has hired more health workers, and has set up medical oxygen plants to improve supply in future outbreaks. Medical oxygen ran out during the second wave.
On top of this, additional critical care infrastructure has been reserved for children, as dedicated facilities for them were shifted to adult COVID-19 patient care in the last two surges. Medicines have been stockpiled for opportunistic infections that can accompany COVID-19, such as mucormycosis. And India is also strengthening its network for tracking potentially dangerous new variants of the virus, with experts noting that this needs to be improved.
And with low vaccine coverage having allowed the virus to spread, there have also been efforts to strengthen India’s COVID-19 vaccination program. Exports of domestically produced doses were halted in the spring to bolster India’s own vaccine supply, and the procurement of vaccines has been handed over from state governments to the federal government.
Vaccine coverage still a problem
India is the world’s leading vaccine producer, and most low- and middle-income countries rely on it for supplies. Bringing in export controls has diminished supplies elsewhere, but has allowed India to speed up its own vaccine administration to more than 5 million doses a day. Despite this, a shortage of doses continues to be an impediment, as does vaccine hesitancy.
Incentives to get people to take a vaccine—such as subsidizing property taxes, offering cheaper air fares, discounted restaurant meals, cheaper groceries and better bank interest rates—have proven a hit. Nevertheless, so far less than 10% of the population is fully vaccinated. Looking back, it’s therefore unlikely that vaccination played a major role in bringing India’s second wave to an end.
Natural immunity generated following infection is likely to have played a bigger role—but even though two-thirds of the population have some COVID-19 antibodies, this isn’t enough to contain the virus. In many Indian states, cases are rising again.
Source https://medicalxpress.com/news/2021-08-india-covid-surge-vaccine-coverage.html
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