Episode 136 Sputnik update

Tue, 05/04/2021 - 18:41

Episode 136: What about Sputnik V?

Ep 136-1: a reminder of the nice paper in the Lancet. Apparently more efficacious: 91.6 %  against PCR confirmed  (symptomatic?) COVID  and with less side effects than the other Adeno’s (AZ and J&J), although Sputnik’s prime is Ad26, just like J&J. Almost too good to be true.

Ep 136-2: In this recent editorial a statement by the Gamelaya company about a staggering 97.6 % protection against infection in 3.8 million fully vaccinated Russians.  There were no cases of cerebral venous sinus thrombosis. Gamaleya also makes its technology available for free, so countries can produce their own supplies. In India, for example, domestic vaccine manufacturers together aim to make 70 million doses a month. Sounds good.

Ep 136-3 A:  The Brazilian Health Regulatory Agency (Anvisa) warns that Sputnik V may contain replication competent adenoviruses, but it does so, based on an interpretation from data by Gamelaya company, which accuses Anvisa of disinformation.  But ANISA is also complaining about lack of transparency at Gamaleya about side effects and quality control.

Ep 136-B: is a press release by Gamaleya, showing that Sputnik V is superior to all other vaccines in Hungary, Mexico and Argentina.  Especially the Hungarian data are difficult to believe: Sputnik associated with 95 infections and 1 death per 100,000 vaccinations, while the corresponding figures for Pfizer are 555 and 32!!!! (AZ, Sinopharm and Moderna are “in between”).

Ep 136-4: While the European Medicines Agency is pondering over Sputnik since 2 months https://www.ema.europa.eu/en/news/ema-starts-rolling-review-sputnik-v-covid-19-vaccine , the European External Action Service (the EU ministries of foreign affairs) are complaining about disinformation by Russia on the other vaccines.  While Hungary is using it at its own risk, the Slovakian government collapsed over a planned Sputnik order.  

 

Is there any independent scientific evidence? Well, I only find three preprints from Argentina:

 

Ep 136-5: Pagotto describes seemingly much more adverse effects than reported in the Luganov paper, but it is all reasonable. Only 1 in 707 subjects had to be hospitalized.

Ep 136-6: Rossana Elena Chahla finds that the first Sputnik vaccine dose in subjects with prior COVID19 elicits a higher antibody response than two doses in uninfected individuals. This is in fact similar to what has been described with other COVID vaccines.

Ep 136-7 : is the most interesting:  8 out of 12 (67%) serum samples from a cohort of recipients of the Gamaleya Sputnik V Ad26 / Ad5 vaccine showed dose response curve slopes

indicative of failure to neutralize rcVSV-CoV2-S: B.1.351. The same set of sera

efficiently neutralized S from B.1.1.7 and showed only moderately reduced activity

against S carrying the E484K substitution alone.

The discussion is also interesting, because it points to the fact that the three most potent vaccines (Pfizer, Moderna and J&J) have genetically locked the S in a prefusion conformation, while A-Z and Sputnik use the “native S”. 

Sera from all vaccine recipients have been shown to be less active against the E848K/Q containing variants (especially the B.1.351 South-African), but it remains unclear whether there are differences between those vaccines.  Side-by-side comparison in neutralization assays with “real viruses” is urgently needed….

An interesting suggestion in this paper is also not to stick to 50 % neutralization titres, but to look for 80 or 90 %.  That value is more variable, but it could be more predictive for “true” in vivo protection.  Depending on the slope of the curve, sera with equal IC50 against a (variant) virus may have quite a different EC80 or EC90.

 

To be followed up

 

Best wishes,

 

Guido  

 

  

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