[Lewis Thomson (OP)]

Linda seeks answers to this question on covid testing post-vaccinations.

"Could you please explain logic behind having a pre travel pcr or antigen test followed by a day 2 pcr test on arrival in uk even though you are double vaccinated."

Can you help her in the comments below?

[evan_au]

Because the vaccines provide very good protection against severe disease, but only good protection against catching & spreading the disease.
- So when cases are high (as with Omicron at present), it is important to continue with masks & social distancing.
- And also with testing, to ensure that you don't infect others.

The reason for testing before departure and after arrival is that the disease has an incubation period, during which the tests won't detect it.
- Test before departure, to reduce the chance of infecting passengers & crew on the plane/in the airport
- Test after arrival, to verify that you didn't catch it just before departure, or in the plane/airport

Background: The current vaccines were all developed to protect against the original Wuhan strain of COVID-19.
- Wait a few months, and two doses only provide around 50% protection against catching the Delta strain (but still very good protection against ICU & death)
- And 3 doses is needed to give significant protection against catching the Omicron strain (Omicron is much less likely to put you in ICU, but the vaccines provide even better protection)

[Petrochemicals]

At the moment it's because countries like china require it, so the consensus is that is what airplane travel requires. Truthfully it doesn't matter at all anywhere in Europe.

[alancalverd]

My double-vaccinated son tested positive with severe symptoms last week. He was sufficiently infectious to infect his pet guinea pig, who is now a potential source.

Airlines have different seating policies: some have restricted the number of passengers and seat them with maximum spacing, others (presumably those short of crew) have restricted the number of flights and cram the passengers close together. But the best place to sample live virus is in the "security" and immigration queues.

 

[Bored chemist]

My double-vaccinated son tested positive with severe symptoms last week. He was sufficiently infectious to infect his pet guinea pig, who is now a potential source.

Airlines have different seating policies: some have restricted the number of passengers and seat them with maximum spacing, others (presumably those short of crew) have restricted the number of flights and cram the passengers close together. But the best place to sample live virus is in the "security" and immigration queues.

 

Was the Guinea pig PCR tested?