Be under no illusions, the COVID-19 pandemic is far from over.
We are currently seeing yet another wave of infections as the Omicron variant diverges into new and even more infections variants, and investigators at the US National Insitute of Allergy and Infectious Diseases have shown that the antibody levels following vaccination wane significantly in about 3 months.
From the NIH news release:
In the new analysis, investigators report that nearly all vaccine combinations evaluated (see table) elicited high levels of neutralizing antibodies to the Omicron BA.1 sub-lineage. However, antibody levels against Omicron were low in the group that received Ad26.COV2.S as both a primary vaccine and boost. Moreover, immune responses to Omicron in all groups waned substantially, with neutralizing antibody levels decreasing 2.4- to 5.3-fold by three months post-boost. Omicron sub-lineages BA.2.12.1 and BA.4/BA.5 were 1.5 and 2.5 times less susceptible to neutralization, respectively, compared to the BA.1 sub-lineage, and 7.5 and 12.4 times less susceptible relative to the ancestral D614G strain. BA.5 currently is the dominant variant in the U.S. The authors note that the findings are consistent with real-world reports showing waning protection against SARS-CoV-2 infection during the Omicron wave in people who received a primary vaccine series plus a booster shot. Additionally, the immune response to Omicron sub-lineages show reduced susceptibility to these rapidly emerging subvariants. The data could be used to inform decisions regarding future vaccine schedule recommendations, including the need for variant vaccine boosting.The findings are published open access in Cell Reports Medicine:
HighlightsSo, the message is a simple no-brainer. Unless you want to run the risk of serious illness, long-term health problems and even death from COVID-19:
- Vaccine boost substantially increases Omicron neutralizing antibody titers
- Boosted neutralization titers to Omicron but not prototypic D614G decline rapidly
- Ad26.COV2.S is better as prime or boost with mRNA vaccines than as homologous boost
- Omicron sublineages exhibit 5–12 times reduced neutralization by mRNA-1273 boost sera
Summary
The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibits reduced susceptibility to vaccine-induced neutralizing antibodies, requiring a boost to generate protective immunity. We assess the magnitude and short-term durability of neutralizing antibodies after homologous and heterologous boosting with mRNA and Ad26.COV2.S vaccines. All prime-boost combinations substantially increase the neutralization titers to Omicron, although the boosted titers decline rapidly within 2 months from the peak response compared with boosted titers against the prototypic D614G variant. Boosted Omicron neutralization titers are substantially higher for homologous mRNA vaccine boosting, and for heterologous mRNA and Ad26.COV2.S vaccine boosting, compared with homologous Ad26.COV2.S boosting. Homologous mRNA vaccine boosting generates nearly equivalent neutralizing activity against Omicron sublineages BA.1, BA.2, and BA.3 but modestly reduced neutralizing activity against BA.2.12.1 and BA.4/BA.5 compared with BA.1. These results have implications for boosting requirements to protect against Omicron and future variants of SARS-CoV-2. This trial was conducted under ClincalTrials.gov: NCT04889209.
We (my self and Cindy T) were infected by our six month old grand-daughter who has since fully recovered. Apparently my daughter and her husband had a long weekend at the beach, and caught it from someone else and brought it home to us, and we had been so careful to avoid crowds and limit other social contacts. As it were, we were fairly miserable for about a week, even though we were both fully vaccinated, the Covid infection wasn't too bad for me, but Cindy T suffered a lot more. Neither of us ended up in the hospital, but Rosa is entirely right in saying to get vaccinated, because if you don't you put friends and family at risk. We will absolutely get additional boosters when available...
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