Sputnik V already has an EUA here in the Philippines, and is meant to ship here soon. If these reports are true, this is very very wrong and concerning. FDA can and should actually try to verify this. https://twitter.com/angie_rasmussen/status/1387397186372005893

Brazil's regulator, Anvisa, says they found replicating adenovirus in the vaccines. The adenovirus vector in the vaccine is just supposed to be a carrier; it shouldn't replicate on its own. it's standard to engineer the adenovirus to make it unable to replicate.

Anvisa appears to have found this by doing a plaque assay in A549 cells. will be very important if this can be replicated. but it would also be nice to see proper data: controls to rule out viral contam; sequence or other data to confirm any recombinant replication-competent AdV

afaik, this is the first such report for Sputnik V, which is why this should be urgently followed up and replicated elsewhere. concerningly, Anvisa says they saw the same thing in all lots tested.

plenty of adenoviruses naturally infect humans & can cause a wide range of disease or no disease at all. the point is, having a replicative vector in the vaccine is quite unexpected, should *not* be intended, and if true the consequences for both safety and efficacy are unknown.

naturally, though, you might reasonably expect that an actively replicating viral vector could interfere with the immune response the vaccine itself is intended to provoke, and so might end up blunting or dampening the protection from the vaccine.

the report from Anvisa is definitely very concerning, but it's worth noting that a plaque assay in itself does not definitely answer the question for good. there are other possible explanations that should be ruled out.

Gamaleya's statement emphatically denies the findings & decries the decision in Brazil as being politically motivated. honestly, transparency of data (from both anvisa and gamaleya) and independent experimental investigation would resolve this. https://sputnikvaccine.com/newsroom/pressreleases/sputnik-v-statement-on-brazilian-health-regulator-anvisa-s-decision-to-postpone-authorization/

Here’s a great commentary breaking down the issue and what it implies for lack of quality control. For those who might not be very familiar with adenovirus vector tech. https://blogs.sciencemag.org/pipeline/archives/2021/04/28/brazil-rejects-the-gamaleya-vaccine