I have heard some people in the hospitality industry on the news suggesting that a vaccine certificate should allow people to travel without the need for PCR tests and self-isolating until the results of the test come through.
Someone on Facebook, and this is therefore a second hand report, said that Lyndon Farnham was endorsing this in an interview on BBC Radio Jersey:
"Heard you on the radio today. Bless you, need to get your facts right..... Mr Farnham was talking about vaccine passports and didn't feel they would be used for pubs etc over here... That's fine. He DID, however, think that when incoming people were coming into Jersey, the passport would mean they didn't need a PCR test. REALLY..... I think Lyndon needs to understand that the vaccine does NOT STOP you catching COVID, it does reduce the symptoms but it can still be caught and transmitted. Please Government of Jersey, DO NOT let this happen."
I hope that Lyndon can tell me that is not the case.
So, let's have some science.
A growing body of evidence suggests that fully vaccinated people are less likely to have asymptomatic infection and potentially less likely to transmit SARS-CoV-2 to others. However, further investigation is ongoing.
This is the really important piece of science:
The risks of SARS-CoV-2 infection in fully vaccinated people cannot be completely eliminated as long as there is continued community transmission of the virus. Vaccinated people could potentially still get COVID-19 and spread it to others.
Vaccines can reduce transmission, but they do not stop it. When travel comes in the 18-40s will not have been vaccinated, and even more critically, the under 18s will not. Testing is currently taking place in the USA on the under 18s, as it is important to have a vaccine roll-out which covers children as well. Before their sudden lockdown in Guernsey, at least 60% of the spread of the virus was in schools.
The risks of SARS-CoV-2 infection in fully vaccinated people cannot be completely eliminated as long as there is continued community transmission of the virus. Vaccinated people could potentially still get COVID-19 and spread it to others.
Vaccines can reduce transmission, but they do not stop it. When travel comes in the 18-40s will not have been vaccinated, and even more critically, the under 18s will not. Testing is currently taking place in the USA on the under 18s, as it is important to have a vaccine roll-out which covers children as well. Before their sudden lockdown in Guernsey, at least 60% of the spread of the virus was in schools.
This means that PCR tests remain the most effective way to block importing the virus back into Jersey.
References:
NCB news notes:
Vaccines can protect against transmission by reducing a person's viral load, or how much virus is present in the body, said Dr. Becky Smith, an associate professor of medicine at Duke University.
"Theoretically, by reducing your viral load, it should prevent your ability to transmit to others," she said. "And even if it doesn't fully prevent transmission, it should lower it significantly."
Nature comments:
In February, independent data scientist Youyang Gu changed the name of his popular COVID-19 forecasting model from ‘Path to Herd Immunity’ to ‘Path to Normality’. He said that reaching a herd-immunity threshold was looking unlikely because of factors such as vaccine hesitancy, the emergence of new variants and the delayed arrival of vaccinations for children.
Gu is a data scientist, but his thinking aligns with that of many in the epidemiology community
A vaccine’s ability to block transmission doesn’t need to be 100% to make a difference. Even 70% effectiveness would be “amazing”, says Samuel Scarpino, a network scientist who studies infectious diseases at Northeastern University in Boston, Massachusetts. But there could still be a substantial amount of virus spread that would make it a lot harder to break transmission chains.
And there's a new danger from Brittany, as Euronews reports:
Now, a new strain of Sars-Cov-2 has been discovered in Brittany in western France. Eight cases have been linked to the new variant which seems to be difficult to detect by the current PCR technique in use.
CR stands for polymerase chain reaction which involves the amplification of the genome of the virus. In this case, Sars-Cov-2 is an RNA virus that is reverse transcribed into DNA and then amplified by using reagents called primers.
The primers are specific to a specific genome sequence. So if there’s a mutation in the sequence that corresponds to these primers, the PCR method just won’t work. Therefore, new PCR methods would have to be developed to target this particular strain- hence the need to develop new testing methods.
NCB news notes:
Vaccines can protect against transmission by reducing a person's viral load, or how much virus is present in the body, said Dr. Becky Smith, an associate professor of medicine at Duke University.
"Theoretically, by reducing your viral load, it should prevent your ability to transmit to others," she said. "And even if it doesn't fully prevent transmission, it should lower it significantly."
Nature comments:
In February, independent data scientist Youyang Gu changed the name of his popular COVID-19 forecasting model from ‘Path to Herd Immunity’ to ‘Path to Normality’. He said that reaching a herd-immunity threshold was looking unlikely because of factors such as vaccine hesitancy, the emergence of new variants and the delayed arrival of vaccinations for children.
Gu is a data scientist, but his thinking aligns with that of many in the epidemiology community
A vaccine’s ability to block transmission doesn’t need to be 100% to make a difference. Even 70% effectiveness would be “amazing”, says Samuel Scarpino, a network scientist who studies infectious diseases at Northeastern University in Boston, Massachusetts. But there could still be a substantial amount of virus spread that would make it a lot harder to break transmission chains.
And there's a new danger from Brittany, as Euronews reports:
Now, a new strain of Sars-Cov-2 has been discovered in Brittany in western France. Eight cases have been linked to the new variant which seems to be difficult to detect by the current PCR technique in use.
CR stands for polymerase chain reaction which involves the amplification of the genome of the virus. In this case, Sars-Cov-2 is an RNA virus that is reverse transcribed into DNA and then amplified by using reagents called primers.
The primers are specific to a specific genome sequence. So if there’s a mutation in the sequence that corresponds to these primers, the PCR method just won’t work. Therefore, new PCR methods would have to be developed to target this particular strain- hence the need to develop new testing methods.
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