The 50/50 split of the dosing is too small to have significant immune boosting effect against the Omicron line.

"According to the science presented in these studies, she added, two full-doses of an Omicron-specific monovalent vaccine would be much more effective than the single half-dose that's in the bivalent booster. "This might have been a good option for vulnerable populations in need of the strongest practically achievable protection."

Imprinting deserves greater attention, Gounder added. "Because the bivalent boosters are a 50-50 blend of the ancestral and BA.4/5 vaccines," she said, "only a half-dose of Omicron-specific vaccine is being administered.""

People should still mask and use other measures of self-protection.

https://www.medpagetoday.com/infectiousdisease/covid19vaccine/102604

On Saturday, January 14, 2023 at 7:54:54 AM UTC-5, bill....@ieee.org wrote:
> On Saturday, January 14, 2023 at 9:47:20 PM UTC+11, Fred Bloggs wrote:
> > The 50/50 split of the dosing is too small to have significant immune boosting effect against the Omicron line.
> >
> > "According to the science presented in these studies, she added, two full-doses of an Omicron-specific monovalent vaccine would be much more effective than the single half-dose that's in the bivalent booster. "This might have been a good option for vulnerable populations in need of the strongest practically achievable protection."
> >
> > Imprinting deserves greater attention, Gounder added. "Because the bivalent boosters are a 50-50 blend of the ancestral and BA.4/5 vaccines," she said, "only a half-dose of Omicron-specific vaccine is being administered.""
> >
> > People should still mask and use other measures of self-protection.
> >
> > https://www.medpagetoday.com/infectiousdisease/covid19vaccine/102604
> They do seem to be obsessed by the antibody titre - which is easy to measure - to the exclusion of any other aspect of the immune response, none of which seem to be as easy to monitor.
>
> Martin Brown has been posting similarly one-eyed stuff over the past six months.
>
> To somebody with a hammer, everything looks like a nail.

You need to give these people credit for having a bit more brainpower than that. The science and clinical trials have confirmed the validity of using the titer as a "correlate of protection (CoP)."

"A CoP is an immune marker that can be used to reliably predict a vaccine’s level of efficacy in preventing a clinically relevant outcome..."

From NEJM no less:

https://www.nejm.org/doi/full/10.1056/NEJMp2211314

When they say the bivalent vaccine produced only a modest increase in correlate, they were being politic. The most accurate way to say the same thing is the bivalent vaccine is only slightly less ineffective against Omicron and its subvariants than the original monovalent vaccine.

>
> --
> Bill Sloman, Sydney

On 14/01/2023 12:54, Anthony William Sloman wrote:
> On Saturday, January 14, 2023 at 9:47:20 PM UTC+11, Fred Bloggs
> wrote:
>> The 50/50 split of the dosing is too small to have significant
>> immune boosting effect against the Omicron line.
>>
>> "According to the science presented in these studies, she added,
>> two full-doses of an Omicron-specific monovalent vaccine would be
>> much more effective than the single half-dose that's in the
>> bivalent booster. "This might have been a good option for
>> vulnerable populations in need of the strongest practically
>> achievable protection."
>>
>> Imprinting deserves greater attention, Gounder added. "Because the
>> bivalent boosters are a 50-50 blend of the ancestral and BA.4/5
>> vaccines," she said, "only a half-dose of Omicron-specific vaccine
>> is being administered.""
>>
>> People should still mask and use other measures of
>> self-protection.
>>
>> https://www.medpagetoday.com/infectiousdisease/covid19vaccine/102604
>
>>
> They do seem to be obsessed by the antibody titre - which is easy to
> measure - to the exclusion of any other aspect of the immune
> response, none of which seem to be as easy to monitor.
>
> Martin Brown has been posting similarly one-eyed stuff over the past
> six months.

It is easy to measure and it is also a fairly good indicator of how
effectively the vaccination will prevent you from catching the disease.
If the antibody titre is high enough it will take down a potential Covid
infection before it manages to become established in the patient.

The other longer lasting immune responses help prevent the disease from
progressing in dangerous ways if you do catch it.

Bivalent vaccines was in all probability a marketing scheme to cut the
useful new Omicron vaccine with the now almost worthless original stuff.
Not much point programming the immune system to fight last year's battle.

> To somebody with a hammer, everything looks like a nail.

You are wildly optimistic. Australia and China both failed to keep
Omicron at bay and now XBB.1.5 is taking America by storm. It remains
unclear whether it will do the same in Europe. It is present in the UK
and appears to have a reproductive advantage over early Omicron strains.

https://www.ecdc.europa.eu/en/news-events/update-sars-cov-2-variants-ecdc-assessment-xbb15-sub-lineage

It hasn't quite made it onto the radar in the UK yet but if it doubles
every 9 days then it soon will do. We had around 3M peak with Covid over
Xmas.

UK is seeing a lot of reinfections of people who were fully vaccinated
and have had Covid (at least) once before with BA.4 and BA.5 - enough to
have fairly decent stats on the fraction of previous strains infected
and how the reinfections pan out:

https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/articles/coronaviruscovid19latestinsights/infections#reinfections

--
Regards,
Martin Brown