Under the terms agreed last week by the US Food and Drug Administration (FDA) and the Centers for Disease Control (CDC), the adenovirus vector vaccine may be administered solely to people who are 18 years old and older or are unable to receive the mRNA vaccines made by Pfizer-BioNTech or Moderna.

An alternate category is a vague “those who would otherwise not receive a Covid-19 vaccine,” meaning the immunocompromised or vaccine skeptics who don’t trust recombinant technologies.

Next to the mRNA versions, J&J’s Covid shot – made by the healthcare giant’s pharmaceuticals offshoot Janssen – is the third and only other Covid vaccine authorized for use in the US. It is given solely under an Emergency Use Authorization (EUA), while the two mRNA vaccines have full FDA approval.

With its own clotting issues, AstraZeneca has held back on applying to the FDA following a dispute with US authorities over clinical trial methodology, and the health agency is taking its time approving the Novavax protein-based shot.

The FDA said last week it had made its decision to restrict the product after reviewing data related to thrombocytopenia syndrome (TTS) in a number of Janssen vaccine recipients roughly one or two weeks after vaccination, the same malady that threatened early recipients of the AZ shot in Europe.

In April last year, the health watchdog temporarily suspended the use of the Janssen vaccine – not quite two months after it issued the EUA – after receiving reports of TTS. It lifted the restrictions days later but in December recommended that mRNA vaccines be awarded preference. The European Medicines Agency (EMA) came to make similar recommendations. 

Up to the present, US health authorities have identified 60 cases of TTS associated with this vaccine, including nine fatalities. In the FDA’s calculation, the ratio is 3.23 reported cases of TTS per million vaccine doses administered.

The Janssen shot early on was hailed as a solution to distributing Covid vaccines to countries without sophisticated infrastructure, due to its longer shelf life and the fact that it was recommended by the manufacturer as a single-dose vaccine. However, it was beset by problems from the outset.

At a time when sufficient doses were hard to come by, initial supplies into Europe were delayed by problems at CDMOs in several countries. Along with the AstraZeneca vaccine, the J&J rollout was hampered by a mix-up at a plant operated by Emergent in the US state of Maryland. The full extent of that glitch is only now becoming transparent.

The biggest disappointment is being felt in Africa. In March this year, J&J announced that subsidiary Janssen had finally completed a manufacturing agreement with South Africa’s Aspen Pharmacare “in Africa for Africa,” where estimates see only about 12% of the continent’s population as having been vaccinated.

The US group said subsequently it had shipped more than 200 million vaccine doses to Africa through a combination of advance purchase agreements with the African Vaccine Acquisition Trust, South Africa and Gavi, the Vaccine Alliance on behalf of the Covax Facility, along with government donations.

According to the latest available information, however, the Aspen facility has found no takers for its output, which Africa CDC Director John Nkengasong said casts doubts on the continuation of production. Nkengasong said African countries are reluctant to pay for the doses when “hundreds of millions” can now be had for free. 

Author: Dede Williams, Freelance Journalist