Flights from the RSA (Cape Town or Johannesburg) to Amsterdam take 11-12 hours.
The Netherlands COVID-19 test requirement for entry is a PCR test within 48 hours before departure or a rapid test 24 hours before departure. Up to an additional 24 hours allowed for delays not the traveler’s fault (e.g. typical airline delays).
A traveler from the RSA could have been last tested up to two and a half days before arriving in Amsterdam (up to three and a half days if there were some bad airline delays). During that time, the traveler could have been infected after the test, or a not-yet-detectable infection at the time of the test could have increased in viral load to become detectable. Travelers using PCR tests are likely to do them as early as possible during the allowed window due to the waiting time needed to get results. Rapid tests reduce the window, but may not be as sensitive (more likely to give false negatives).
Regarding COVID-19 test detection of the Omicron variant, Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern says that “Current SARS-CoV-2 PCR diagnostics continue to detect this variant. Several labs have indicated that for one widely used PCR test, one of the three target genes is not detected (called S gene dropout or S gene target failure) and this test can therefore be used as marker for this variant, pending sequencing confirmation.”
In other words, such a PCR test result of positive for two target genes but negative for the one missing in the Omicron variant may suggest that the person has the Omicron variant, but a PCR test result of positive for all three target genes may suggest that the person has some other variant.
Travel restrictions are really just kabuki theater. You can’t keep disease from spreading and that has been well tested in the literature. At best, it delays the arrival by 1-2 weeks.
The delay is the point in my view. It gives countries time to assess the situation, collect data and make appropriate preparations, if necessary or prudent. The point isn’t prevention of transmission since the travel ban doesn’t take affect until tomorrow.
We need a much better sequencing surveillance of the samples collected for testing. So far, there are no concerted worldwide efforts to do this. This is not human genome we are talking about, sequencing of this virus is a much easier task.
Agree, delay as much as possible to assess transmissibility, disease severity, VE, vaccine adjustments and treatments. My problem is other countries put the restrictions up days ago, but not us. If another country shoots IBMs at us, we put up a shield immediately, not wait 4 days or whatever it is.
Seems that COVID-19 travel bans are often done after the virus has gotten in (“closing the barn door after the horses have escaped” type of thing). Not surprising, given asymptomatic and presymptomatic spread…
But also, the Omicron-related travel bans target only countries in southern Africa, rather than all places where the Omicron variant has been found (e.g. Canada, the UK, Belgium, Italy, Hong Kong, Israel). Presumably, this is because there is little travel volume from there compared to the other places to the travel banning countries, so it looks like “doing something” even though it does very little.
The mRNA vaccines in particular — Moderna’s and Pfizer-BioNTech’s — were built with technology that should permit rapid modification. Pfizer’s scientists “can adapt the current vaccine within six weeks and ship initial batches within 100 days in the event of an escape variant” that eludes the immune system, said Jerica Pitts, a spokeswoman for Pfizer.
Moderna could update its current vaccine in about two months and have clinical results in about three months if necessary, he said.
Both companies also plan to test whether booster shots will bolster the immune system enough to fend off the new variant. Boosters of the Pfizer-BioNTech and Moderna vaccines have been shown to raise antibody levels significantly.
I like that WHO basically says we don’t know anything yet.
Ugur Sahin, BioNTech CEO, today said that the vaccines are likely to protect against severe disease (defined as requiring hospitalization and/or intensive care).
Sahin said antibodies brought about by vaccination could struggle latching on to the new virus lineage but he added that t-cells, another line of immune defence, were set to recognise the vast parts of Omicron’s spike protein that remain unchanged.
While antibodies bind to viruses directly and prevent infections, longer lasting t-cells attack cells that have already been hijacked by the virus, warding off viral replication and severe disease.
Note this is a bit of different take than Stephane Bancel, Moderna CEO, had yesterday.
Regarding the RSA physician stating she saw mild symptoms in patients…well, that’s a small slice of reality, not to mention the majority of cases with Delta are mild too.
The statement about T-cells seems to be an indirect endorsement of the J&J / Janssen vaccine, which tends to produce a greater T-cell response but a smaller antibody response, compared to the Pfizer / BioNTech vaccine.
Ironic. Have you seen data of the relative T-Cell response of the rest of the WHO approved products? Dr. Sahin does have much more of a global perspective than those of us who are US centered.
A common vaccine used outside the US is the Oxford / AstraZeneca ChAdOx1 vaccine (CoviShield is the same vaccine license-manufactured in India). This is an adenovirus vector vaccine, similar in concept to the J&J / Janssen vaccine, although it uses a different vector virus. Some other vaccines also use adenovirus vectors.
There is some speculation on it giving greater T-cell response than mRNA vaccines, but not as much in terms of actual studies:
Traveler diagnosed with the Omicron variant returned to the US from the RSA on November 22. This was two days before the Omicron variant was reported by the RSA to the WHO. So the virus (as usual) got a head start on travel bans.
Traveler had two Moderna vaccine doses but was not boosted afterward, and reported “very mild” symptoms.
We still don’t know enough, but even if antibodies allow an infection, T cell immunity may very well still prevent severe disease…this is what Dr. Sahin, CEO of BioNTech, was saying in the article I posted above yesterday.