CDC eyes safety of J&J COVID jab as EU backs booster
Johnson & Johnson's also-ran COVID-19 vaccine has been cleared in the EU as a booster shot, although its role in the US could be impacted by new data on rare blood clots.
A Centres for Disease and Control Prevention (CDC) advisory committee is scheduled to meet today to discuss the new results, according to a Washington Post report, which point to continued rates of blood clots among people taking the vaccine.
The single-dose adenoviral shot – much like the AstraZeneca/Oxford University vaccine – has been linked to rare cases of a rare and severe type of blood clot. There have been more cases in young and middle-aged women, which the Post said will be discussed at today's meeting.
Use of J&J's vaccine was halted for 10 days in the spring after six women taking the shot experienced blood clots, leading to one death, but dosing resumed after a review concluded its benefits outweighed the risks. The new report says there have been nine deaths related to the issue.
The US vaccination campaign has been carried out mostly with two-dose mRNA vaccines from Pfizer/BioNTech and Moderna – with 282 million and 184 million doses delivered, respectively – with J&J trailing in a distant third place with just over 17 million doses administered.
There was better news for J&J yesterday when the EMA's human medicines committee recommended that a booster dose of the shot may be given at least two months after a first dose in people aged 18 years and older.
It can also be used as a booster after two doses of the mRNA vaccines, in line with FDA advice published in October.
Having the flexibility to 'mix-and-match' vaccines is likely to be important in the coming weeks as countries scramble to step up their booster campaigns in an attempt to limit the impact of the highly transmissible Omicron variant of SARS-CoV-2, which looks set to become dominant.
The EMA committee has already backed the use of third doses of the Pfizer/BioNTech and Moderna shots – given six months after the primary course – and is reviewing the AZ booster data. The UK meanwhile has trimmed the lag between primary vaccination and a third dose to three months.
GSK/Sanofi facing another delay
Meanwhile, another COVID-19 vaccine in development at Sanofi and GlaxoSmithKline has been affected by a further delay – because the two companies are struggling to find enough uninfected subjects for their pivotal clinical trial.
Preliminary results from the study have shown the jab generated encouraging increases in antibody levels against SARS-CoV-2 when given to people already vaccinated with AZ, J&J, Pfizer/BioNTech and Moderna vaccines.
The news is another setback for the programme, which has already been held up by lacklustre data in an earlier clinical trial, forcing the formulation to be modified.
In the vaccine's favour is that it is being tested as Omicron has emerged, so it should have specific data on the new variant prior to authorisation. The trial was due to end this year but is now expected to complete sometime in the first quarter of 2022.
