Evaluation of Waning of SARS-CoV-2 Vaccine–Induced Immunity A Systematic Review and Meta-analysis

This is an article that sums up 40 studies.  We quickly noted that many people lost immunity quickly.  This article put numbers and times to quantify the VE or Vaccine Effectiveness over time.  The exponential decay function of time equation was used  VE(t) = Ae^{−w t}

How does the effectiveness of COVID-19 vaccines against laboratory-confirmed Omicron infection and symptomatic disease change at different times?  Going from last dose administration and number of doses?  How does this compare with previously circulating SARS-CoV-2 variants and subvariants?

This systematic review and meta-analysis of secondary data from 40 studies found that the estimated vaccine effectiveness against both laboratory-confirmed Omicron infection and symptomatic disease was lower than 20% at 6 months from the administration of the primary vaccination cycle.  This dropped to less than 30% at 9 months from the administration of a booster dose. The studies compared the Delta variant, a more prominent and found quicker waning of protection with the Delta type variants!

Results

A total of 799 original articles and 149 reviews published in peer-reviewed journals.  35 preprinted journal studies were also used. Of these, 40 studies were included in the analysis. Pooled estimates of VE of a primary vaccination cycle against laboratory-confirmed Omicron infection and symptomatic disease were both lower than 20% at 6 months from last dose administration. Booster doses restored VE to levels comparable to those acquired soon after the administration of the primary cycle. However, 9 months after booster administration, VE against Omicron was lower than 30% against laboratory-confirmed infection and symptomatic disease. The half-life of VE against symptomatic infection was estimated to be 87 days (95% CI, 67-129 days) for Omicron compared with 316 days (95% CI, 240-470 days) for Delta. Similar waning rates of VE were found for different age segments of the population.

Conclusions and Relevance

These findings suggest that the effectiveness of COVID-19 vaccines against laboratory-confirmed Omicron or Delta infection and symptomatic disease rapidly wanes over time after the primary vaccination cycle and booster dose.  These results can inform the design of appropriate targets and timing for future vaccination programs.

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Link to full Article

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2804451?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=050323