COVID-19 vaccine – Long term immune decline and breakthrough infections

Khoury, Johad; Najjar‐Debbiny, Ronza; Hanna, Ayman; Jabbour, Adel; Ahmad, Yara Abu; Saffuri, Amer; Abu-Sinni, Majdole; Shkeiri, Rashed; Elemy, Ameer; Hakim, Fahed

doi:10.1016/j.vaccine.2021.10.038

Cited by 97 publications

(89 citation statements)

References 9 publications

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“…In light of waning immunity over time [23][24][25][26] , health authorities in many countries are now recommending booster vaccinations. 12 The relatively low antibody levels and protective capacity in recipients of one dose of Ad26.COV2.S motivated us to investigate their levels following an mRNA booster, due to the relatively high proportion of Icelanders that received Ad26.COV2.S.…”

Section: Discussionmentioning

confidence: 99%

“…Waning of antibody levels and protection following vaccination against SARS-CoV-2 has been reported. [23][24][25][26] For recipients of two doses of ChAdOx1 and one booster dose of mRNA-1273, antibody levels were substantially increased two months after the booster (12x, 95% CI: 8.9-17x) (Figure 4A and 4B). We used measurements obtained 8-154 days after booster to estimate the waning of antibody and inhibition levels and found it to correspond to a half-life of 51 (95% CI: 48-55) and 42 days respectively (95% CI: 38-46)(Figure 4).…”

Section: Antibody Waning Following An Mrna Booster Dosementioning

confidence: 99%

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Effect of booster vaccination against Delta and Omicron variants in Iceland

Norddahl

Melsted

Gunnarsdóttir

et al. 2022

Preprint

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By the end of July 2021, the majority of the Icelandic population had received vaccination against COVID-19. In mid-July a wave of SARS-CoV-2 infections, dominated by the delta variant, spread through the population, followed by an omicron wave in December. A booster vaccination campaign was initiated to curb the spread of the virus. We estimated the risk of infection for different vaccine combinations using vaccination data from 276,028 persons and 963,557 qPCR tests for 277,687 persons. We measured anti-Spike-RBD antibody levels and ACE2-Spike binding inhibitory activity in 371 persons who received one of four recommended vaccination schedules with or without an mRNA vaccine booster. Overall, we found different antibody levels and inhibitory activity between recommended vaccination schedules, which was reflected in the observed risk of SARS-CoV-2 infections. We observed an increased protection following mRNA boosters, against both omicron and delta variant infections, although BNT162b2 boosters provided greater protection against omicron than mRNA-1273 boosters.

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Section: Discussionmentioning

confidence: 99%

Section: Antibody Waning Following An Mrna Booster Dosementioning

confidence: 99%

Effect of booster vaccination against Delta and Omicron variants in Iceland

Norddahl

Melsted

Gunnarsdóttir

et al. 2022

Preprint

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“…Similar to observations for convalescent sera after natural SARS‐CoV‐2 infection, 10 , 11 neutralizing antibodies waned significantly within months after vaccination. 12 , 13 , 14 , 15 , 16 , 17 Compared with mRNA vaccines that are dependent on intracellular production of spike protein antigens and the ability of mRNA itself to mobilize innate immune activity by inducing both higher neutralization titers and strong cellular immunity, 18 , 19 alum‐adjuvanted inactivated SARS‐CoV‐2 vaccines induced lower neutralization titers and weaker cellular immunity after two‐dose immunization and exhibited a low protection rate in clinical phase III trials. 8 , 20 , 21 To improve vaccine efficacy, additional vaccination schedules with homologous or heterologous boost strategies for alum‐adjuvanted inactivated SARS‐CoV‐2 vaccines are being considered.…”

Section: Introductionmentioning

confidence: 99%

Comparison of immune responses induced by two or three doses of an alum‐adjuvanted inactivated SARS‐CoV‐2 vaccine in mice

Luan

Wang

Cao

et al. 2022

Journal of Medical Virology

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Waning antibodies and rapidly emerging variants are challenges for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine development. Adjusting existing immunization schedules and further boosting strategies are under consideration. Here, the immune responses induced by an alum-adjuvanted inactivated SARS-CoV-2 vaccine in mice were compared among immunization schedules with two or three doses. For the two-dose schedule, a 0-28-day schedule induced 5-fold stronger spike-specific IgG responses than a 0-14-day schedule, with only a slight elevation of spike-specific cellular immunity 14 days after the last immunization. A third homologous boost 2 or 5 months after the second dose for the 0-28-day schedule slightly strengthened humoral responses (1.3-fold for the 0-1-3-month schedule, and 1.8-fold for the 0-1-6-month schedule) 14 days after the last immunization. Additionally, a third homologous boost (especially with the 0-1-3-month schedule) induced significantly stronger cell-mediated immunity than both two-dose immunization schedules for all indexes tested, with a response similar to that induced by a one-dose heterologous boost with BNT162b2 in clinical trials, according to cellular immunity analysis (1.5-fold). These T cell responses were Th2 oriented, with good CD4+ and CD8+ memory. These results may offer clues for applying a homologous boosting strategy for alum-adjuvanted inactivated SARS-CoV-2 vaccines.

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“…It may be related to : i) a variable proportion of the population not yet immunised, ii) anti-Spike antibody levels decrease over time after two doses of either RNA or ChAdOx vaccines 1 , and iii) vaccination being less efficient against the delta (B.1.617.2) variant of concern (VOC), which effectively became the single circulating form of SARS-CoV-2 during early summer 2021, compared to the original strain 2 . Several studies have characterised the rate of such breakthrough infections in vaccinated persons 3 , and reported that this risk increased over time after primary vaccination [4][5][6] . It has also been shown that even with the delta variant, in the general population, the rate of Covid-19-related hospitalisations 7,8 , intensive care unit (ICU) admissions, and mortality 9 were much lower in those who received two doses of the aforementioned vaccines.…”

Section: Introductionmentioning

confidence: 99%

Symptoms and severity in vaccinated and unvaccinated patients hospitalised with SARS-CoV-2 delta (B.1.617.2) variant infection

Épaulard

Abgrall

Lefèbvre

et al. 2022

Preprint

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Background: The diffusion of the SARS-CoV-2 delta (B.1.617.2) variant and the waning of immune response after primary Covid-19 vaccination favoured the breakthrough SARS-CoV-2 infections in vaccinated subjects. To assess the impact of vaccination, we determined the severity of infection in hospitalised patients according to vaccine status. Methods: We retrospectively analysed data from patients hospitalised in 10 centres with a SARS-CoV-2 infection (delta variant) from July to November 2021: i) all patients who had completed their primary vaccination at least 14 days before hospital admission; and ii) the same number of completely unvaccinated patients. We assessed the impact of vaccination and other risk factors through logistic regression. Findings: We included 955 patients (474 vaccinated and 481 unvaccinated). Vaccinated patients were significantly older, more frequently males, and with more comorbidities. They were less often admitted for Covid-19 (59.3% vs. 75.1%, p<0.001), showed fewer lung lesions, and required oxygen less frequently (57.5% vs. 73.0%, p<0.001), at a lower flow (3.0 vs. 6.0 L/min, p<0.001), and for a shorter duration (3 vs. 6 days, p<0.001). They less frequently required intensive care unit admission (16.2 % vs. 36.0 %, p<0.001). Mortality at day 28 was not different between the two groups (16.7% vs. 12.2%, p=0.075), but multivariate logistic regression showed that vaccination significantly decreased the risk of negative outcomes, including mortality, even when considering older patients, and those with comorbidities. Conclusions: Among patients hospitalised with a delta variant SARS-CoV-2 infection, vaccination was associated with less severe forms, even in the presence of comorbidities.

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COVID-19 vaccine – Long term immune decline and breakthrough infections

Cited by 97 publications

References 9 publications

Effect of booster vaccination against Delta and Omicron variants in Iceland

Effect of booster vaccination against Delta and Omicron variants in Iceland

Comparison of immune responses induced by two or three doses of an alum‐adjuvanted inactivated SARS‐CoV‐2 vaccine in mice

Symptoms and severity in vaccinated and unvaccinated patients hospitalised with SARS-CoV-2 delta (B.1.617.2) variant infection

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