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Kozlov, M. (2021). Waning COVID super-immunity raises questions about Omicron. Nature. https://doi.org/10.1038/d41586-021-03674-1

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Prof. Christina Pagel 🇺🇦. (2022, March 8). What could be causing it? Likely combo of: 1—Dominant BA.2 causing more infections (we await ONS!) 2—Reduction in masks, self-isolation & testing enabling more infections 3—Waning boosters in older people esp I worry that we will be stuck at high levels for long time. 2/2 https://t.co/xZ2SLFNVkS [Tweet]. @chrischirp. https://twitter.com/chrischirp/status/1501250081693048838

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Eric Feigl-Ding. (2022, January 13). WATCH📺—Despite 97.5% of all adults in England🏴󠁧󠁢󠁥󠁮󠁧󠁿 with antibodies to #COVID19 (via vax/infection)–hospitalizations still surging. Why? Because variants like #Omicron are adapting. Need multivalent vax, plus ➡️N95 & ventilation are agnostic to variants—Key! Https://t.co/gDNRJIWojX [Tweet]. @DrEricDing. https://twitter.com/DrEricDing/status/1481732793482813443

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Tom Wenseleers. (2022, January 30). Seems that the second Omicron subvariant BA.2 may soon be about to cause cases to start rising again in South Africa... Or at least to stop the decline in new infections. Shows how fast immunity wanes & evolution can catch up. Https://t.co/3y4xqPgZ0L [Tweet]. @TWenseleers. https://twitter.com/TWenseleers/status/1487919837670219781

Health Nerd. (2022, January 15). It was always likely that immunity to COVID-19 would wane, and we now know the median time to waning is around 1.5-2 years post infection for most people, sometimes less 😕 [Tweet]. @GidMK. https://twitter.com/GidMK/status/1482188340091060229

Devlin, H., Davis, N., & correspondents, N. D. S. (2022, January 14). Expect another Omicron wave in early summer, Sage says. The Guardian. https://www.theguardian.com/world/2022/jan/14/expect-another-covid-omicron-wave-in-early-summer-sage-says

Jennifer Cohn ✍🏻 📢. (2022, January 11). This chart says it all. If u got double vaccinated early on & are not yet boosted, ur effectively unvaccinated against Omicron infection. Thus, many adults & teens are effectively unvaccinated against infection. Kids got vaccinated recently & thus may be in a safer position. 1/ [Tweet]. @jennycohn1. https://twitter.com/jennycohn1/status/1481034404260581377

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Yahoo Finance. (2021, September 21). “The J&J results exceed expectations,” Yale Radiology and Public Health Professor @thehowie says about the COVID-19 vaccine. “They continue to point out that the J&J vaccine is highly effective even as a one dose vaccine.” https://t.co/AOsxo9IwKT [Tweet]. @YahooFinance. https://twitter.com/YahooFinance/status/1440356401826590727

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John Burn-Murdoch. (2021, August 23). NEW: in the last couple of weeks there have a lot of new studies out assessing vaccine efficacy, many of which have touched on the question of waning immunity. Unsurprisingly, these have prompted a lot of questions. Time for a thread to summarise what we do and don’t know: [Tweet]. @jburnmurdoch. https://twitter.com/jburnmurdoch/status/1429878189011111936

David Dowdy on Twitter: “@NEJM joining the waning immunity debate. I’m going to push back a bit. Data from @UCSDHealth of vax effectiveness in health workers: 94% in June, 65% in July. Interpreted as ‘likely to be due to...delta and waning immunity over time, compounded by end of masking requirements.’ https://t.co/flDOfBbTs7” / Twitter. (n.d.). Retrieved September 2, 2021, from https://twitter.com/davidwdowdy/status/1433254675915157504?s=20

Bilich et al showed that IgG and IgA antibody responses declined during the six-month follow-up, raising concerns that humoral immunity against SARS-CoV-2 may not provide longterm protection. Anti-S1 antibody responses decrease over time, whereas anti-nucleocapsid antibody titres persist, this is important in the context of vaccine development focusing on the induction of immune responses to the RBD of the spike protein.

Bilich T, Nelde A, Heitmann JS, Maringer Y, Roerden M, Bauer J, et al. T cell and antibody kinetics delineate SARS-CoV-2 peptides mediating long-term immune responses in COVID-19 convalescent individuals. Science Translational Medicine. 2021:eabf7517.

Zhou et al showed that serum IgM and IgG, especially in patients with moderate‐to‐high levels, declined significantly between week 4 to 10 after illness onset. Paper suggests that a decline in IgM may be an indicator of virus clearance. Although IgG levels declined to low levels within 11 weeks, they remained detectable.

Figueiredo‐Campos et al quantified IgM, IgG and IgA and showed that although titres reduced, IgG antibodies remained robust with confirmed neutralisation activity for up to 6 months

Zhou W, Xu X, Chang Z, Wang H, Zhong X, Tong X, Liu T, Li Y. The dynamic changes of serum IgM and IgG against SARS-CoV-2 in patients with COVID-19. J Med Virol. 2021 Feb;93(2):924-933. doi: 10.1002/jmv.26353. Epub 2020 Sep 28. PMID: 32706425; PMCID: PMC7404900.

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