11 June Episode 146 More real world data and update on beta and delta variants

Fri, 06/11/2021 - 11:15

Dear colleagues,

A short update on real world data and various data on beta (South-African) and delta (Indian).  This episode is a bit superficial, because I have to follow my family, who left already on holiday….

Not sure how much time I can dedicate on COVID over the next three weeks.

Just got my second shot of AZ yesterday and I have not the slightest side effect.

Ep 146-1 : a comment in Nature on the disability cost by COVID:

  • According to UK data: 1 in 5 people who were hospitalized with COVID had a new disability after discharge
  • In US: 1 in 10 of those who had NOT been hospitalized, had ongoing symptoms 12 weeks after first positive test.
  • A comparison shows that in Pakistan, the total burden of death + disability is rather similar to UK, but occurs more in the “working age group”

A remarkable quote: “It seems self-evident that vaccines are a wise investment for wealthy nations, given the huge toll that the pandemic places on economies.

Indeed, for this reason, we think it might be cost-effective for HICs to vaccinate the entire global population, not just their own citizens.

See also the didactic explanations on DALY’s and QALY’s and the nice graphs.

 

Ep 146-2A: The debate on the role of children:

Data from Serrana, Brazil (unpublished) and Israel suggest that vaccinating adults suffices to lower infection rates in children to a similar extent, but data from UK provide a more mixed picture, with outbreaks still occurring in primary and secondary schools. The variants, especially the delta (Indian) is worrying and some scientist argue that vaccination, especially in adolescents,  is important, not only to prevent rather rare disease, but also to prevent any further disruption of the normal curriculum by temporary school closure, because of outbreaks.

Ep 146-2B: A small testimony in the Guardian on the disruption by a COVID-infected child in a family.  Could be any of us…

 

Ep 146-3: More data and consideration on “real world efficacy”

 

Comment paper in Nature (146-3A): While in Public Health England reports on very positive results by both Pfizer and Astra-Zeneca, with 85-90 % protection against symptomatic disease, a study in long-term care facilities, confirms 2 doses Pfizer efficacy of 90 % in the staff, but only 64 % in the elderly residents (average 80 years old) in Ep 146-3B.   It is not clear from the paper how good the protection against severe disease or death was.

 

In the same line, Pieter Pannus and others (146 3C) show for Belgium find very low levels of antibodies after mRNA vaccination of not-previously infected residents and also some staff of nursing homes.  Clearly, there is a population that already is or could become very vulnerable, especially when variants come in.  

 

With regard to the beta (South-African B.1.315) variant, it was noted before that protection against symptomatic disease was 75 % in Qatar by Pfizer, but much less (20 %?) by Astra-Zeneca in South-Africa.  In both cases, we also do not know what the protection was against severe disease. 

 

Ep 146-4: The delta (Indian) variant (B.1.617.2) and beta (B.1.315-South African)

 

146-4A: Berna l describes “modest reduction” of protection after two doses  against symptomatic delta as compared to alpha (B.1.117) infections: for Pfizer from 93.4 to 87.9 % and for A-Z from 66.1 to 59.8 %.   Clearly, in this study AZ is really inferior to Pfizer (as opposed to most earlier reports from UK).

 

146-4B:  Planas shows that neutralizing antibodies in convalescent and vaccinated subjects against beta (South-African) and delta are very much lower and again AZ is clearly inferior to Pfizer in this respect.  See Fig on last page (24)

 

146-4C: Riou then shows that despite lower neut, the T cell responses are largely conserved against beta.  This study is done in convalescent patients.  Note also that T cell responses are measured by evaluating IFN-gamma production, which is a parameter that is of unknown importance for protective immunity.  For instance in HIV-infected subjects, IFN-G production is preserved for a long time, while untreated patients progress in the disease. More important parameters are “polyfunctionality” (simultaneous production of several cytokines) and virus-suppressive activity, which are not measured here.

 

146-4D on breakthrough infections in 326 Indian HCW, vaccinated between Jan and March with either BBV152 (the Indian inactivated COVID vaccine) or Astra-Zeneca during the present wave, where delta is dominant.  A total of 36  (11%) symptomatic breakthrough were noted  > 14 days after second dose until beginning of June.  The incidence was higher for the inactivated vaccine (13.7 %) as compared to AZ (8.2 %), but this difference was NS. Of those 94 % were mild and the incidence was 4.5 times lower in those who had been COVID infected before.       

 

Best wishes,

 

Guido

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