A new hurdle occurred in the race to bring a vaccine candidate against Covid-19 to the market. A few days after AstraZeneca, Johnson & Johnson had to announce the decision to "temporarily paused further dosing in all our Covid-19 vaccine candidate clinical trials, including the Phase 3 ENSEMBLE trial, due to an unexplained illness in a study participant". "Adverse events - illnesses, accidents, etc. - even those that are serious, are an expected part of any clinical study, especially large studies", the company added in a statement.

Despite being several months behind other vaccines makers in developing a vaccine candidate, Johnson & Johnson had the opportunity to reduce the gap. The company was among the short list of players with a vaccine candidate, JNJ-78436735. The "ENSEMBLE study" planned to enroll up to 60 000 volunteers across three continents and to evaluate the safety and efficacy of a single vaccine dose versus placebo in preventing Covid-19. That was the first big trial of a Covid-19 inoculation that might work after just one shot. Johnson & Johnson expected results of the "ENSEMBLE trial" by year end or early 2021.

Other front-runners such as Pfizer Inc. and partner BioNTech SE, Moderna Inc., or AstraZeneca Plc in conjunction with the University of Oxford, are further along in late-stage trials targeting tens of thousands of healthy participants, but with multiple doses to inject. Pfizer thinks it could determine whether its product is safe and effective based on preliminary data before the end of October, while Moderna is aiming for the end of November.

September 6, AstraZeneca also had to trigger a "voluntary pause" to vaccination across all global trials of its AZD1222 project, "to allow an independent committee to review the safety data of a single event of an unexplained illness that occurred in the UK Phase III trial". Their recommendations have been supported by international regulators in the UK, Brazil, South Africa, India and Japan, who have deemed that the trials were safe to resume. The situation was a bit more complicated in the United-States, where AstraZeneca continues to work with the Food and Drug Administration (FDA) to facilitate review of the information needed to make a decision regarding resumption of the US trial.

If the conclusions are positive for Jonhson &s; Johnson and if the company is able to resume the clinical trials, the one-dose regimen could eliminate the dropouts associated with trying to get people to return for a second shot. It would also enable the company to vaccinate up to 1 billion people each year. Meanwhile with a two-dose regimen, few manufacturers are able to reach this figure. Johnson & Johnson's vaccine candidate would also give the company another edge as it doesn't require freezing and can remain viable in its liquid form for several months.

While waiting for further results on the fight against Covid-19 pandemic, Johnson & Johnson registered another success on the acquisitions front. Beginning of October, the New Brunswick-based company completed the acquisition of Momenta Pharmaceuticals, that develops novel therapies for immune-mediated diseases and rare diseases, for approximately $6.5 billion.